Imported Upstream version 1.3.0+dfsgupstream/1.3.0+dfsg

1 files changed, 2194 insertions, 0 deletions

diff --git a/src/health.c b/src/health.c
new file mode 100644
index 00000000..3156cd08
--- /dev/null
+++ b/src/health.c
@@ -0,0 +1,2194 @@
+#include "common.h"
+
+#define RRDVAR_MAX_LENGTH 1024
+
+static const char *health_default_exec = PLUGINS_DIR "/alarm-email.sh";
+int health_enabled = 1;
+
+// ----------------------------------------------------------------------------
+// RRDVAR management
+
+static inline int rrdvar_fix_name(char *variable) {
+    int fixed = 0;
+    while(*variable) {
+        if (!isalnum(*variable) && *variable != '.' && *variable != '_') {
+            *variable++ = '_';
+            fixed++;
+        }
+        else
+            variable++;
+    }
+
+    return fixed;
+}
+
+int rrdvar_compare(void* a, void* b) {
+    if(((RRDVAR *)a)->hash < ((RRDVAR *)b)->hash) return -1;
+    else if(((RRDVAR *)a)->hash > ((RRDVAR *)b)->hash) return 1;
+    else return strcmp(((RRDVAR *)a)->name, ((RRDVAR *)b)->name);
+}
+
+static inline RRDVAR *rrdvar_index_add(avl_tree_lock *tree, RRDVAR *rv) {
+    RRDVAR *ret = (RRDVAR *)avl_insert_lock(tree, (avl *)(rv));
+    if(ret != rv)
+        debug(D_VARIABLES, "Request to insert RRDVAR '%s' into index failed. Already exists.", rv->name);
+
+    return ret;
+}
+
+static inline RRDVAR *rrdvar_index_del(avl_tree_lock *tree, RRDVAR *rv) {
+    RRDVAR *ret = (RRDVAR *)avl_remove_lock(tree, (avl *)(rv));
+    if(!ret)
+        error("Request to remove RRDVAR '%s' from index failed. Not Found.", rv->name);
+
+    return ret;
+}
+
+static inline RRDVAR *rrdvar_index_find(avl_tree_lock *tree, const char *name, uint32_t hash) {
+    RRDVAR tmp;
+    tmp.name = (char *)name;
+    tmp.hash = (hash)?hash:simple_hash(tmp.name);
+
+    return (RRDVAR *)avl_search_lock(tree, (avl *)&tmp);
+}
+
+static inline void rrdvar_free(RRDHOST *host, avl_tree_lock *tree, RRDVAR *rv) {
+    (void)host;
+
+    if(!rv) return;
+
+    if(tree)
+        rrdvar_index_del(tree, rv);
+
+    freez(rv->name);
+    freez(rv);
+}
+
+static inline RRDVAR *rrdvar_create_and_index(const char *scope, avl_tree_lock *tree, const char *name, int type, calculated_number *value) {
+    char *variable = strdupz(name);
+    rrdvar_fix_name(variable);
+    uint32_t hash = simple_hash(variable);
+
+    RRDVAR *rv = rrdvar_index_find(tree, variable, hash);
+    if(unlikely(!rv)) {
+        debug(D_VARIABLES, "Variable '%s' not found in scope '%s'. Creating a new one.", variable, scope);
+
+        rv = callocz(1, sizeof(RRDVAR));
+        rv->name = variable;
+        rv->hash = hash;
+        rv->type = type;
+        rv->value = value;
+
+        RRDVAR *ret = rrdvar_index_add(tree, rv);
+        if(unlikely(ret != rv)) {
+            debug(D_VARIABLES, "Variable '%s' in scope '%s' already exists", variable, scope);
+            rrdvar_free(NULL, NULL, rv);
+            rv = NULL;
+        }
+        else
+            debug(D_VARIABLES, "Variable '%s' created in scope '%s'", variable, scope);
+    }
+    else {
+        // already exists
+        freez(variable);
+        rv = NULL;
+    }
+
+    return rv;
+}
+
+// ----------------------------------------------------------------------------
+// RRDVAR lookup
+
+calculated_number rrdvar2number(RRDVAR *rv) {
+    switch(rv->type) {
+        case RRDVAR_TYPE_CALCULATED: {
+            calculated_number *n = (calculated_number *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_TIME_T: {
+            time_t *n = (time_t *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_COLLECTED: {
+            collected_number *n = (collected_number *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_TOTAL: {
+            total_number *n = (total_number *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_INT: {
+            int *n = (int *)rv->value;
+            return *n;
+        }
+
+        default:
+            error("I don't know how to convert RRDVAR type %d to calculated_number", rv->type);
+            return NAN;
+    }
+}
+
+void dump_variable(void *data) {
+    RRDVAR *rv = (RRDVAR *)data;
+    debug(D_HEALTH, "%50s : %20.5Lf", rv->name, rrdvar2number(rv));
+}
+
+int health_variable_lookup(const char *variable, uint32_t hash, RRDCALC *rc, calculated_number *result) {
+    RRDSET *st = rc->rrdset;
+    RRDVAR *rv;
+
+    if(!st) return 0;
+
+    rv = rrdvar_index_find(&st->variables_root_index, variable, hash);
+    if(rv) {
+        *result = rrdvar2number(rv);
+        return 1;
+    }
+
+    rv = rrdvar_index_find(&st->rrdfamily->variables_root_index, variable, hash);
+    if(rv) {
+        *result = rrdvar2number(rv);
+        return 1;
+    }
+
+    rv = rrdvar_index_find(&st->rrdhost->variables_root_index, variable, hash);
+    if(rv) {
+        *result = rrdvar2number(rv);
+        return 1;
+    }
+
+    debug(D_HEALTH, "Available local chart '%s' variables:", st->id);
+    avl_traverse_lock(&st->variables_root_index, dump_variable);
+
+    debug(D_HEALTH, "Available family '%s' variables:", st->rrdfamily->family);
+    avl_traverse_lock(&st->rrdfamily->variables_root_index, dump_variable);
+
+    debug(D_HEALTH, "Available host '%s' variables:", st->rrdhost->hostname);
+    avl_traverse_lock(&st->rrdhost->variables_root_index, dump_variable);
+
+    return 0;
+}
+
+// ----------------------------------------------------------------------------
+// RRDSETVAR management
+
+RRDSETVAR *rrdsetvar_create(RRDSET *st, const char *variable, int type, void *value, uint32_t options) {
+    debug(D_VARIABLES, "RRDVARSET create for chart id '%s' name '%s' with variable name '%s'", st->id, st->name, variable);
+    RRDSETVAR *rs = (RRDSETVAR *)callocz(1, sizeof(RRDSETVAR));
+
+    char buffer[RRDVAR_MAX_LENGTH + 1];
+    snprintfz(buffer, RRDVAR_MAX_LENGTH, "%s.%s", st->id, variable);
+    rs->fullid = strdupz(buffer);
+
+    snprintfz(buffer, RRDVAR_MAX_LENGTH, "%s.%s", st->name, variable);
+    rs->fullname = strdupz(buffer);
+
+    rs->variable = strdupz(variable);
+
+    rs->type = type;
+    rs->value = value;
+    rs->options = options;
+    rs->rrdset = st;
+
+    rs->local       = rrdvar_create_and_index("local",  &st->variables_root_index, rs->variable, rs->type, rs->value);
+    rs->family      = rrdvar_create_and_index("family", &st->rrdfamily->variables_root_index, rs->fullid, rs->type, rs->value);
+    rs->host        = rrdvar_create_and_index("host",   &st->rrdhost->variables_root_index, rs->fullid, rs->type, rs->value);
+    rs->family_name = rrdvar_create_and_index("family", &st->rrdfamily->variables_root_index, rs->fullname, rs->type, rs->value);
+    rs->host_name   = rrdvar_create_and_index("host",   &st->rrdhost->variables_root_index, rs->fullname, rs->type, rs->value);
+
+    rs->next = st->variables;
+    st->variables = rs;
+
+    return rs;
+}
+
+void rrdsetvar_rename_all(RRDSET *st) {
+    debug(D_VARIABLES, "RRDSETVAR rename for chart id '%s' name '%s'", st->id, st->name);
+
+    // only these 2 can change name
+    // rs->family_name
+    // rs->host_name
+
+    char buffer[RRDVAR_MAX_LENGTH + 1];
+    RRDSETVAR *rs, *next = st->variables;
+    while((rs = next)) {
+        next = rs->next;
+
+        snprintfz(buffer, RRDVAR_MAX_LENGTH, "%s.%s", st->name, rs->variable);
+
+        if (strcmp(buffer, rs->fullname)) {
+            // name changed
+            rrdvar_free(st->rrdhost, &st->rrdfamily->variables_root_index, rs->family_name);
+            rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_name);
+
+            freez(rs->fullname);
+            rs->fullname = strdupz(st->name);
+            rs->family_name = rrdvar_create_and_index("family", &st->rrdfamily->variables_root_index, rs->fullname, rs->type, rs->value);
+            rs->host_name   = rrdvar_create_and_index("host",   &st->rrdhost->variables_root_index, rs->fullname, rs->type, rs->value);
+        }
+    }
+
+    rrdsetcalc_link_matching(st);
+}
+
+void rrdsetvar_free(RRDSETVAR *rs) {
+    RRDSET *st = rs->rrdset;
+    debug(D_VARIABLES, "RRDSETVAR free for chart id '%s' name '%s', variable '%s'", st->id, st->name, rs->variable);
+
+    rrdvar_free(st->rrdhost, &st->variables_root_index, rs->local);
+    rrdvar_free(st->rrdhost, &st->rrdfamily->variables_root_index, rs->family);
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host);
+    rrdvar_free(st->rrdhost, &st->rrdfamily->variables_root_index, rs->family_name);
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_name);
+
+    if(st->variables == rs) {
+        st->variables = rs->next;
+    }
+    else {
+        RRDSETVAR *t;
+        for (t = st->variables; t && t->next != rs; t = t->next);
+        if(!t) error("RRDSETVAR '%s' not found in chart '%s' variables linked list", rs->fullname, st->id);
+        else t->next = rs->next;
+    }
+
+    freez(rs->fullid);
+    freez(rs->fullname);
+    freez(rs->variable);
+    freez(rs);
+}
+
+// ----------------------------------------------------------------------------
+// RRDDIMVAR management
+
+#define RRDDIMVAR_ID_MAX 1024
+
+RRDDIMVAR *rrddimvar_create(RRDDIM *rd, int type, const char *prefix, const char *suffix, void *value, uint32_t options) {
+    RRDSET *st = rd->rrdset;
+
+    debug(D_VARIABLES, "RRDDIMSET create for chart id '%s' name '%s', dimension id '%s', name '%s%s%s'", st->id, st->name, rd->id, (prefix)?prefix:"", rd->name, (suffix)?suffix:"");
+
+    if(!prefix) prefix = "";
+    if(!suffix) suffix = "";
+
+    char buffer[RRDDIMVAR_ID_MAX + 1];
+    RRDDIMVAR *rs = (RRDDIMVAR *)callocz(1, sizeof(RRDDIMVAR));
+
+    rs->prefix = strdupz(prefix);
+    rs->suffix = strdupz(suffix);
+
+    snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s%s%s", rs->prefix, rd->id, rs->suffix);
+    rs->id = strdupz(buffer);
+
+    snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s%s%s", rs->prefix, rd->name, rs->suffix);
+    rs->name = strdupz(buffer);
+
+    snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s.%s", rd->rrdset->id, rs->id);
+    rs->fullidid = strdupz(buffer);
+
+    snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s.%s", rd->rrdset->id, rs->name);
+    rs->fullidname = strdupz(buffer);
+
+    snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s.%s", rd->rrdset->name, rs->id);
+    rs->fullnameid = strdupz(buffer);
+
+    snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s.%s", rd->rrdset->name, rs->name);
+    rs->fullnamename = strdupz(buffer);
+
+    rs->type = type;
+    rs->value = value;
+    rs->options = options;
+    rs->rrddim = rd;
+
+    rs->local_id     = rrdvar_create_and_index("local", &st->variables_root_index, rs->id, rs->type, rs->value);
+    rs->local_name   = rrdvar_create_and_index("local", &st->variables_root_index, rs->name, rs->type, rs->value);
+
+    rs->family_id    = rrdvar_create_and_index("family", &st->rrdfamily->variables_root_index, rs->id, rs->type, rs->value);
+    rs->family_name  = rrdvar_create_and_index("family", &st->rrdfamily->variables_root_index, rs->name, rs->type, rs->value);
+
+    rs->host_fullidid     = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index, rs->fullidid, rs->type, rs->value);
+    rs->host_fullidname   = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index, rs->fullidname, rs->type, rs->value);
+    rs->host_fullnameid   = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index, rs->fullnameid, rs->type, rs->value);
+    rs->host_fullnamename = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index, rs->fullnamename, rs->type, rs->value);
+
+    rs->next = rd->variables;
+    rd->variables = rs;
+
+    return rs;
+}
+
+void rrddimvar_rename_all(RRDDIM *rd) {
+    RRDSET *st = rd->rrdset;
+    debug(D_VARIABLES, "RRDDIMSET rename for chart id '%s' name '%s', dimension id '%s', name '%s'", st->id, st->name, rd->id, rd->name);
+
+    RRDDIMVAR *rs, *next = rd->variables;
+    while((rs = next)) {
+        next = rs->next;
+
+        if (strcmp(rd->name, rs->name)) {
+            char buffer[RRDDIMVAR_ID_MAX + 1];
+            // name changed
+
+            // name
+            rrdvar_free(st->rrdhost, &st->variables_root_index, rs->local_name);
+            freez(rs->name);
+            snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s%s%s", rs->prefix, rd->name, rs->suffix);
+            rs->name = strdupz(buffer);
+            rs->local_name = rrdvar_create_and_index("local", &st->variables_root_index, rs->name, rs->type, rs->value);
+
+            rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_fullidname);
+            freez(rs->fullidname);
+            snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s.%s", st->id, rs->name);
+            rs->fullidname = strdupz(buffer);
+            rs->host_fullidname = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index,
+                                                             rs->fullidname, rs->type, rs->value);
+
+            // fullnameid
+            rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_fullnameid);
+            freez(rs->fullnameid);
+            snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s.%s", st->name, rs->id);
+            rs->fullnameid = strdupz(buffer);
+            rs->host_fullnameid = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index,
+                                                          rs->fullnameid, rs->type, rs->value);
+
+            // fullnamename
+            rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_fullnamename);
+            freez(rs->fullnamename);
+            snprintfz(buffer, RRDDIMVAR_ID_MAX, "%s.%s", st->name, rs->name);
+            rs->fullnamename = strdupz(buffer);
+            rs->host_fullnamename = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index,
+                                                          rs->fullnamename, rs->type, rs->value);
+        }
+    }
+}
+
+void rrddimvar_free(RRDDIMVAR *rs) {
+    RRDDIM *rd = rs->rrddim;
+    RRDSET *st = rd->rrdset;
+    debug(D_VARIABLES, "RRDDIMSET free for chart id '%s' name '%s', dimension id '%s', name '%s', prefix='%s', suffix='%s'", st->id, st->name, rd->id, rd->name, rs->prefix, rs->suffix);
+
+    rrdvar_free(st->rrdhost, &st->variables_root_index, rs->local_id);
+    rrdvar_free(st->rrdhost, &st->variables_root_index, rs->local_name);
+
+    rrdvar_free(st->rrdhost, &st->rrdfamily->variables_root_index, rs->family_id);
+    rrdvar_free(st->rrdhost, &st->rrdfamily->variables_root_index, rs->family_name);
+
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_fullidid);
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_fullidname);
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_fullnameid);
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rs->host_fullnamename);
+
+    if(rd->variables == rs) {
+        debug(D_VARIABLES, "RRDDIMSET removing first entry for chart id '%s' name '%s', dimension id '%s', name '%s'", st->id, st->name, rd->id, rd->name);
+        rd->variables = rs->next;
+    }
+    else {
+        debug(D_VARIABLES, "RRDDIMSET removing non-first entry for chart id '%s' name '%s', dimension id '%s', name '%s'", st->id, st->name, rd->id, rd->name);
+        RRDDIMVAR *t;
+        for (t = rd->variables; t && t->next != rs; t = t->next) ;
+        if(!t) error("RRDDIMVAR '%s' not found in dimension '%s/%s' variables linked list", rs->name, st->id, rd->id);
+        else t->next = rs->next;
+    }
+
+    freez(rs->prefix);
+    freez(rs->suffix);
+    freez(rs->id);
+    freez(rs->name);
+    freez(rs->fullidid);
+    freez(rs->fullidname);
+    freez(rs->fullnameid);
+    freez(rs->fullnamename);
+    freez(rs);
+}
+
+// ----------------------------------------------------------------------------
+// RRDCALC management
+
+static inline const char *rrdcalc_status2string(int status) {
+    switch(status) {
+        case RRDCALC_STATUS_UNINITIALIZED:
+            return "UNINITIALIZED";
+
+        case RRDCALC_STATUS_UNDEFINED:
+            return "UNDEFINED";
+
+        case RRDCALC_STATUS_CLEAR:
+            return "CLEAR";
+
+        case RRDCALC_STATUS_RAISED:
+            return "RAISED";
+
+        case RRDCALC_STATUS_WARNING:
+            return "WARNING";
+
+        case RRDCALC_STATUS_CRITICAL:
+            return "CRITICAL";
+
+        default:
+            return "UNKNOWN";
+    }
+}
+
+static void rrdsetcalc_link(RRDSET *st, RRDCALC *rc) {
+    debug(D_HEALTH, "Health linking alarm '%s.%s' to chart '%s' of host '%s'", rc->chart?rc->chart:"NOCHART", rc->name, st->id, st->rrdhost->hostname);
+
+    rc->last_status_change = time(NULL);
+    rc->rrdset = st;
+
+    rc->rrdset_next = st->alarms;
+    rc->rrdset_prev = NULL;
+    st->alarms = rc;
+
+    if(rc->update_every < rc->rrdset->update_every) {
+        error("Health alarm '%s.%s' has update every %d, less than chart update every %d. Setting alarm update frequency to %d.", rc->rrdset->id, rc->name, rc->update_every, rc->rrdset->update_every, rc->rrdset->update_every);
+        rc->update_every = rc->rrdset->update_every;
+    }
+
+    if(!isnan(rc->green) && isnan(st->green)) {
+        debug(D_HEALTH, "Health alarm '%s.%s' green threshold set from %Lf to %Lf.", rc->rrdset->id, rc->name, rc->rrdset->green, rc->green);
+        st->green = rc->green;
+    }
+
+    if(!isnan(rc->red) && isnan(st->red)) {
+        debug(D_HEALTH, "Health alarm '%s.%s' red threshold set from %Lf to %Lf.", rc->rrdset->id, rc->name, rc->rrdset->red, rc->red);
+        st->red = rc->red;
+    }
+
+    rc->local  = rrdvar_create_and_index("local",  &st->variables_root_index, rc->name, RRDVAR_TYPE_CALCULATED, &rc->value);
+    rc->family = rrdvar_create_and_index("family", &st->rrdfamily->variables_root_index, rc->name, RRDVAR_TYPE_CALCULATED, &rc->value);
+
+    char fullname[RRDVAR_MAX_LENGTH + 1];
+    snprintfz(fullname, RRDVAR_MAX_LENGTH, "%s.%s", st->id, rc->name);
+    rc->hostid   = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index, fullname, RRDVAR_TYPE_CALCULATED, &rc->value);
+
+    snprintfz(fullname, RRDVAR_MAX_LENGTH, "%s.%s", st->name, rc->name);
+    rc->hostname = rrdvar_create_and_index("host", &st->rrdhost->variables_root_index, fullname, RRDVAR_TYPE_CALCULATED, &rc->value);
+
+	if(!rc->units) rc->units = strdupz(st->units);
+}
+
+static inline int rrdcalc_is_matching_this_rrdset(RRDCALC *rc, RRDSET *st) {
+    if(     (rc->hash_chart == st->hash      && !strcmp(rc->chart, st->id)) ||
+            (rc->hash_chart == st->hash_name && !strcmp(rc->chart, st->name)))
+        return 1;
+
+    return 0;
+}
+
+// this has to be called while the RRDHOST is locked
+inline void rrdsetcalc_link_matching(RRDSET *st) {
+    // debug(D_HEALTH, "find matching alarms for chart '%s'", st->id);
+
+    RRDCALC *rc;
+    for(rc = st->rrdhost->alarms; rc ; rc = rc->next) {
+        if(rc->rrdset) continue;
+
+        if(rrdcalc_is_matching_this_rrdset(rc, st))
+            rrdsetcalc_link(st, rc);
+    }
+}
+
+// this has to be called while the RRDHOST is locked
+inline void rrdsetcalc_unlink(RRDCALC *rc) {
+    RRDSET *st = rc->rrdset;
+
+    if(!st) {
+        error("Requested to unlink RRDCALC '%s.%s' which is not linked to any RRDSET", rc->chart?rc->chart:"NOCHART", rc->name);
+        return;
+    }
+
+    RRDHOST *host = st->rrdhost;
+
+    debug(D_HEALTH, "Health unlinking alarm '%s.%s' from chart '%s' of host '%s'", rc->chart?rc->chart:"NOCHART", rc->name, st->id, host->hostname);
+
+    // unlink it
+    if(rc->rrdset_prev)
+        rc->rrdset_prev->rrdset_next = rc->rrdset_next;
+
+    if(rc->rrdset_next)
+        rc->rrdset_next->rrdset_prev = rc->rrdset_prev;
+
+    if(st->alarms == rc)
+        st->alarms = rc->rrdset_next;
+
+    rc->rrdset_prev = rc->rrdset_next = NULL;
+
+    rrdvar_free(st->rrdhost, &st->variables_root_index, rc->local);
+    rc->local = NULL;
+
+    rrdvar_free(st->rrdhost, &st->rrdfamily->variables_root_index, rc->family);
+    rc->family = NULL;
+
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rc->hostid);
+    rc->hostid = NULL;
+
+    rrdvar_free(st->rrdhost, &st->rrdhost->variables_root_index, rc->hostname);
+    rc->hostname = NULL;
+
+    rc->rrdset = NULL;
+
+    // RRDCALC will remain in RRDHOST
+    // so that if the matching chart is found in the future
+    // it will be applied automatically
+}
+
+RRDCALC *rrdcalc_find(RRDSET *st, const char *name) {
+    RRDCALC *rc;
+    uint32_t hash = simple_hash(name);
+
+    for( rc = st->alarms; rc ; rc = rc->rrdset_next ) {
+        if(rc->hash == hash && !strcmp(rc->name, name))
+            return rc;
+    }
+
+    return NULL;
+}
+
+static inline int rrdcalc_exists(RRDHOST *host, const char *name, uint32_t hash) {
+    RRDCALC *rc;
+
+    // make sure it does not already exist
+    for(rc = host->alarms; rc ; rc = rc->next) {
+        if (rc->hash == hash && !strcmp(name, rc->name)) {
+            error("Health alarm '%s' already exists in host '%s'.", name, host->hostname);
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+static inline void rrdcalc_create_part2(RRDHOST *host, RRDCALC *rc) {
+    rrdhost_check_rdlock(host);
+
+    if(rc->calculation) {
+        rc->calculation->this = &rc->value;
+        rc->calculation->after = &rc->db_after;
+        rc->calculation->before = &rc->db_before;
+        rc->calculation->rrdcalc = rc;
+    }
+
+    if(rc->warning) {
+        rc->warning->this = &rc->value;
+        rc->warning->after = &rc->db_after;
+        rc->warning->before = &rc->db_before;
+        rc->warning->rrdcalc = rc;
+    }
+
+    if(rc->critical) {
+        rc->critical->this = &rc->value;
+        rc->critical->after = &rc->db_after;
+        rc->critical->before = &rc->db_before;
+        rc->critical->rrdcalc = rc;
+    }
+
+    // link it to the host
+    rc->next = host->alarms;
+    host->alarms = rc;
+
+    // link it to its chart
+    RRDSET *st;
+    for(st = host->rrdset_root; st ; st = st->next) {
+        if(rrdcalc_is_matching_this_rrdset(rc, st)) {
+            rrdsetcalc_link(st, rc);
+            break;
+        }
+    }
+}
+
+static inline uint32_t rrdcalc_fullname(char *fullname, size_t len, const char *chart, const char *name) {
+    snprintfz(fullname, len - 1, "%s%s%s", chart?chart:"", chart?".":"", name);
+    rrdvar_fix_name(fullname);
+    return simple_hash(fullname);
+}
+
+static inline RRDCALC *rrdcalc_create(RRDHOST *host, const char *name, const char *chart, const char *dimensions,
+                        const char *units, const char *info,
+                        int group_method, int after, int before, int update_every, uint32_t options,
+                        calculated_number green, calculated_number red,
+                        const char *exec, const char *source,
+                        const char *calc, const char *warn, const char *crit) {
+
+    char fullname[RRDVAR_MAX_LENGTH + 1];
+    uint32_t hash = rrdcalc_fullname(fullname, RRDVAR_MAX_LENGTH + 1, chart, name);
+
+    if(rrdcalc_exists(host, fullname, hash))
+        return NULL;
+
+    RRDCALC *rc = callocz(1, sizeof(RRDCALC));
+
+    rc->name = strdupz(name);
+    rc->hash = simple_hash(rc->name);
+
+    rc->chart = strdupz(chart);
+    rc->hash_chart = simple_hash(rc->chart);
+
+    if(dimensions) rc->dimensions = strdupz(dimensions);
+
+    rc->green = green;
+    rc->red = red;
+    rc->value = NAN;
+    rc->old_value = NAN;
+
+    rc->group = group_method;
+    rc->after = after;
+    rc->before = before;
+    rc->update_every = update_every;
+    rc->options = options;
+
+    if(exec) rc->exec = strdupz(exec);
+    if(source) rc->source = strdupz(source);
+    if(units) rc->units = strdupz(units);
+    if(info) rc->info = strdupz(info);
+
+    if(calc) {
+        rc->calculation = expression_parse(calc, NULL, NULL);
+        if(!rc->calculation)
+            error("Health alarm '%s.%s': failed to parse calculation expression '%s'", chart, name, calc);
+    }
+    if(warn) {
+        rc->warning = expression_parse(warn, NULL, NULL);
+        if(!rc->warning)
+            error("Health alarm '%s.%s': failed to re-parse warning expression '%s'", chart, name, warn);
+    }
+    if(crit) {
+        rc->critical = expression_parse(crit, NULL, NULL);
+        if(!rc->critical)
+            error("Health alarm '%s.%s': failed to re-parse critical expression '%s'", chart, name, crit);
+    }
+
+    debug(D_HEALTH, "Health runtime added alarm '%s.%s': exec '%s', green %Lf, red %Lf, lookup: group %d, after %d, before %d, options %u, dimensions '%s', update every %d, calculation '%s', warning '%s', critical '%s', source '%s",
+          (rc->chart)?rc->chart:"NOCHART",
+          rc->name,
+          (rc->exec)?rc->exec:"DEFAULT",
+          rc->green,
+          rc->red,
+          rc->group,
+          rc->after,
+          rc->before,
+          rc->options,
+          (rc->dimensions)?rc->dimensions:"NONE",
+          rc->update_every,
+          (rc->calculation)?rc->calculation->parsed_as:"NONE",
+          (rc->warning)?rc->warning->parsed_as:"NONE",
+          (rc->critical)?rc->critical->parsed_as:"NONE",
+          rc->source
+    );
+
+    rrdcalc_create_part2(host, rc);
+    return rc;
+}
+
+void rrdcalc_free(RRDHOST *host, RRDCALC *rc) {
+    if(!rc) return;
+
+    debug(D_HEALTH, "Health removing alarm '%s.%s' of host '%s'", rc->chart?rc->chart:"NOCHART", rc->name, host->hostname);
+
+    // unlink it from RRDSET
+    if(rc->rrdset) rrdsetcalc_unlink(rc);
+
+    // unlink it from RRDHOST
+    if(rc == host->alarms)
+        host->alarms = rc->next;
+
+    else if(host->alarms) {
+        RRDCALC *t, *last = host->alarms;
+
+        for(t = last->next; t && t != rc; last = t, t = t->next) ;
+        if(last && last->next == rc)
+            last->next = rc->next;
+        else
+            error("Cannot unlink alarm '%s.%s' from host '%s': not found", rc->chart?rc->chart:"NOCHART", rc->name, host->hostname);
+    }
+    else
+        error("Cannot unlink unlink '%s.%s' from host '%s': This host does not have any calculations", rc->chart?rc->chart:"NOCHART", rc->name, host->hostname);
+
+    expression_free(rc->calculation);
+    expression_free(rc->warning);
+    expression_free(rc->critical);
+
+    freez(rc->name);
+    freez(rc->chart);
+    freez(rc->family);
+    freez(rc->dimensions);
+    freez(rc->exec);
+    freez(rc->source);
+    freez(rc->units);
+    freez(rc->info);
+    freez(rc);
+}
+
+// ----------------------------------------------------------------------------
+// RRDCALCTEMPLATE management
+
+void rrdcalctemplate_link_matching(RRDSET *st) {
+    RRDCALCTEMPLATE *rt;
+
+    for(rt = st->rrdhost->templates; rt ; rt = rt->next) {
+        if(rt->hash_context == st->hash_context && !strcmp(rt->context, st->context)) {
+
+            RRDCALC *rc = rrdcalc_create(st->rrdhost, rt->name, st->id,
+                           rt->dimensions, rt->units, rt->info, rt->group, rt->after, rt->before, rt->update_every, rt->options,
+                           rt->green, rt->red, rt->exec, rt->source,
+                           (rt->calculation)?rt->calculation->source:NULL,
+                           (rt->warning)?rt->warning->source:NULL,
+                           (rt->critical)?rt->critical->source:NULL);
+
+            if(!rc)
+                error("Health tried to create alarm from template '%s', but it failed", rt->name);
+
+#ifdef NETDATA_INTERNAL_CHECKS
+            else if(rc->rrdset != st)
+                error("Health alarm '%s.%s' should be linked to chart '%s', but it is not", rc->chart?rc->chart:"NOCHART", rc->name, st->id);
+#else
+            (void)rc;
+#endif
+        }
+    }
+}
+
+static inline void rrdcalctemplate_free(RRDHOST *host, RRDCALCTEMPLATE *rt) {
+    debug(D_HEALTH, "Health removing template '%s' of host '%s'", rt->name, host->hostname);
+
+    if(host->templates) {
+        if(host->templates == rt) {
+            host->templates = rt->next;
+        }
+        else {
+            RRDCALCTEMPLATE *t, *last = host->templates;
+            for (t = last->next; t && t != rt; last = t, t = t->next ) ;
+            if(last && last->next == rt) {
+                last->next = rt->next;
+                rt->next = NULL;
+            }
+            else
+                error("Cannot find RRDCALCTEMPLATE '%s' linked in host '%s'", rt->name, host->hostname);
+        }
+    }
+
+    expression_free(rt->calculation);
+    expression_free(rt->warning);
+    expression_free(rt->critical);
+
+    freez(rt->name);
+    freez(rt->exec);
+    freez(rt->context);
+    freez(rt->source);
+    freez(rt->units);
+    freez(rt->info);
+    freez(rt->dimensions);
+    freez(rt);
+}
+
+// ----------------------------------------------------------------------------
+// load health configuration
+
+#define HEALTH_CONF_MAX_LINE 4096
+
+#define HEALTH_ALARM_KEY "alarm"
+#define HEALTH_TEMPLATE_KEY "template"
+#define HEALTH_ON_KEY "on"
+#define HEALTH_LOOKUP_KEY "lookup"
+#define HEALTH_CALC_KEY "calc"
+#define HEALTH_EVERY_KEY "every"
+#define HEALTH_GREEN_KEY "green"
+#define HEALTH_RED_KEY "red"
+#define HEALTH_WARN_KEY "warn"
+#define HEALTH_CRIT_KEY "crit"
+#define HEALTH_EXEC_KEY "exec"
+#define HEALTH_UNITS_KEY "units"
+#define HEALTH_INFO_KEY "info"
+
+static inline int rrdcalc_add_alarm_from_config(RRDHOST *host, RRDCALC *rc) {
+    {
+        char fullname[RRDVAR_MAX_LENGTH + 1];
+        uint32_t hash = rrdcalc_fullname(fullname, RRDVAR_MAX_LENGTH + 1, rc->chart, rc->name);
+
+        if (rrdcalc_exists(host, fullname, hash))
+            return 0;
+    }
+
+    if(!rc->chart) {
+        error("Health configuration for alarm '%s' does not have a chart", rc->name);
+        return 0;
+    }
+
+    if(!rc->update_every) {
+        error("Health configuration for alarm '%s.%s' has no frequency (parameter 'every'). Ignoring it.", rc->chart?rc->chart:"NOCHART", rc->name);
+        return 0;
+    }
+
+    if(!RRDCALC_HAS_DB_LOOKUP(rc) && !rc->warning && !rc->critical) {
+        error("Health configuration for alarm '%s.%s' is useless (no calculation, no warning and no critical evaluation)", rc->chart?rc->chart:"NOCHART", rc->name);
+        return 0;
+    }
+
+    debug(D_HEALTH, "Health configuration adding alarm '%s.%s': exec '%s', green %Lf, red %Lf, lookup: group %d, after %d, before %d, options %u, dimensions '%s', update every %d, calculation '%s', warning '%s', critical '%s', source '%s",
+          rc->chart?rc->chart:"NOCHART",
+          rc->name,
+          (rc->exec)?rc->exec:"DEFAULT",
+          rc->green,
+          rc->red,
+          rc->group,
+          rc->after,
+          rc->before,
+          rc->options,
+          (rc->dimensions)?rc->dimensions:"NONE",
+          rc->update_every,
+          (rc->calculation)?rc->calculation->parsed_as:"NONE",
+          (rc->warning)?rc->warning->parsed_as:"NONE",
+          (rc->critical)?rc->critical->parsed_as:"NONE",
+          rc->source
+    );
+
+    rrdcalc_create_part2(host, rc);
+    return 1;
+}
+
+static inline int rrdcalctemplate_add_template_from_config(RRDHOST *host, RRDCALCTEMPLATE *rt) {
+    if(!rt->context) {
+        error("Health configuration for template '%s' does not have a context", rt->name);
+        return 0;
+    }
+
+    if(!rt->update_every) {
+        error("Health configuration for template '%s' has no frequency (parameter 'every'). Ignoring it.", rt->name);
+        return 0;
+    }
+
+    if(!RRDCALCTEMPLATE_HAS_CALCULATION(rt) && !rt->warning && !rt->critical) {
+        error("Health configuration for template '%s' is useless (no calculation, no warning and no critical evaluation)", rt->name);
+        return 0;
+    }
+
+    RRDCALCTEMPLATE *t;
+    for (t = host->templates; t ; t = t->next) {
+        if(t->hash_name == rt->hash_name && !strcmp(t->name, rt->name)) {
+            error("Health configuration template '%s' already exists for host '%s'.", rt->name, host->hostname);
+            return 0;
+        }
+    }
+
+    debug(D_HEALTH, "Health configuration adding template '%s': context '%s', exec '%s', green %Lf, red %Lf, lookup: group %d, after %d, before %d, options %u, dimensions '%s', update every %d, calculation '%s', warning '%s', critical '%s', source '%s'",
+          rt->name,
+          (rt->context)?rt->context:"NONE",
+          (rt->exec)?rt->exec:"DEFAULT",
+          rt->green,
+          rt->red,
+          rt->group,
+          rt->after,
+          rt->before,
+          rt->options,
+          (rt->dimensions)?rt->dimensions:"NONE",
+          rt->update_every,
+          (rt->calculation)?rt->calculation->parsed_as:"NONE",
+          (rt->warning)?rt->warning->parsed_as:"NONE",
+          (rt->critical)?rt->critical->parsed_as:"NONE",
+          rt->source
+    );
+
+    rt->next = host->templates;
+    host->templates = rt;
+    return 1;
+}
+
+static inline int health_parse_duration(char *string, int *result) {
+    // make sure it is a number
+    if(!*string || !(isdigit(*string) || *string == '+' || *string == '-')) {
+        *result = 0;
+        return 0;
+    }
+
+    char *e = NULL;
+    calculated_number n = strtold(string, &e);
+    if(e && *e) {
+        switch (*e) {
+            case 'Y':
+                *result = (int) (n * 86400 * 365);
+                break;
+            case 'M':
+                *result = (int) (n * 86400 * 30);
+                break;
+            case 'w':
+                *result = (int) (n * 86400 * 7);
+                break;
+            case 'd':
+                *result = (int) (n * 86400);
+                break;
+            case 'h':
+                *result = (int) (n * 3600);
+                break;
+            case 'm':
+                *result = (int) (n * 60);
+                break;
+
+            default:
+            case 's':
+                *result = (int) (n);
+                break;
+        }
+    }
+    else
+       *result = (int)(n);
+
+    return 1;
+}
+
+static inline int health_parse_db_lookup(
+        size_t line, const char *path, const char *file, char *string,
+        int *group_method, int *after, int *before, int *every,
+        uint32_t *options, char **dimensions
+) {
+    debug(D_HEALTH, "Health configuration parsing database lookup %zu@%s/%s: %s", line, path, file, string);
+
+    if(*dimensions) freez(*dimensions);
+    *dimensions = NULL;
+    *after = 0;
+    *before = 0;
+    *every = 0;
+    *options = 0;
+
+    char *s = string, *key;
+
+    // first is the group method
+    key = s;
+    while(*s && !isspace(*s)) s++;
+    while(*s && isspace(*s)) *s++ = '\0';
+    if(!*s) {
+        error("Health configuration invalid chart calculation at line %zu of file '%s/%s': expected group method followed by the 'after' time, but got '%s'",
+              line, path, file, key);
+        return 0;
+    }
+
+    if((*group_method = web_client_api_request_v1_data_group(key, -1)) == -1) {
+        error("Health configuration at line %zu of file '%s/%s': invalid group method '%s'",
+              line, path, file, key);
+        return 0;
+    }
+
+    // then is the 'after' time
+    key = s;
+    while(*s && !isspace(*s)) s++;
+    while(*s && isspace(*s)) *s++ = '\0';
+
+    if(!health_parse_duration(key, after)) {
+        error("Health configuration at line %zu of file '%s/%s': invalid duration '%s' after group method",
+              line, path, file, key);
+        return 0;
+    }
+
+    // sane defaults
+    *every = abs(*after);
+
+    // now we may have optional parameters
+    while(*s) {
+        key = s;
+        while(*s && !isspace(*s)) s++;
+        while(*s && isspace(*s)) *s++ = '\0';
+        if(!*key) break;
+
+        if(!strcasecmp(key, "at")) {
+            char *value = s;
+            while(*s && !isspace(*s)) s++;
+            while(*s && isspace(*s)) *s++ = '\0';
+
+            if (!health_parse_duration(value, before)) {
+                error("Health configuration at line %zu of file '%s/%s': invalid duration '%s' for '%s' keyword",
+                      line, path, file, value, key);
+            }
+        }
+        else if(!strcasecmp(key, HEALTH_EVERY_KEY)) {
+            char *value = s;
+            while(*s && !isspace(*s)) s++;
+            while(*s && isspace(*s)) *s++ = '\0';
+
+            if (!health_parse_duration(value, every)) {
+                error("Health configuration at line %zu of file '%s/%s': invalid duration '%s' for '%s' keyword",
+                      line, path, file, value, key);
+            }
+        }
+        else if(!strcasecmp(key, "absolute") || !strcasecmp(key, "abs") || !strcasecmp(key, "absolute_sum")) {
+            *options |= RRDR_OPTION_ABSOLUTE;
+        }
+        else if(!strcasecmp(key, "min2max")) {
+            *options |= RRDR_OPTION_MIN2MAX;
+        }
+        else if(!strcasecmp(key, "null2zero")) {
+            *options |= RRDR_OPTION_NULL2ZERO;
+        }
+        else if(!strcasecmp(key, "percentage")) {
+            *options |= RRDR_OPTION_PERCENTAGE;
+        }
+        else if(!strcasecmp(key, "unaligned")) {
+            *options |= RRDR_OPTION_NOT_ALIGNED;
+        }
+        else if(!strcasecmp(key, "of")) {
+            if(*s && strcasecmp(s, "all"))
+               *dimensions = strdupz(s);
+            break;
+        }
+        else {
+            error("Health configuration at line %zu of file '%s/%s': unknown keyword '%s'",
+                  line, path, file, key);
+        }
+    }
+
+    return 1;
+}
+
+static inline char *health_source_file(size_t line, const char *path, const char *filename) {
+    char buffer[FILENAME_MAX + 1];
+    snprintfz(buffer, FILENAME_MAX, "%zu@%s/%s", line, path, filename);
+    return strdupz(buffer);
+}
+
+static inline void strip_quotes(char *s) {
+    while(*s) {
+        if(*s == '\'' || *s == '"') *s = ' ';
+        s++;
+    }
+}
+
+int health_readfile(const char *path, const char *filename) {
+    debug(D_HEALTH, "Health configuration reading file '%s/%s'", path, filename);
+
+    static uint32_t hash_alarm = 0, hash_template = 0, hash_on = 0, hash_calc = 0, hash_green = 0, hash_red = 0, hash_warn = 0, hash_crit = 0, hash_exec = 0, hash_every = 0, hash_lookup = 0, hash_units = 0, hash_info = 0;
+    char buffer[HEALTH_CONF_MAX_LINE + 1];
+
+    if(unlikely(!hash_alarm)) {
+        hash_alarm = simple_uhash(HEALTH_ALARM_KEY);
+        hash_template = simple_uhash(HEALTH_TEMPLATE_KEY);
+        hash_on = simple_uhash(HEALTH_ON_KEY);
+        hash_calc = simple_uhash(HEALTH_CALC_KEY);
+        hash_lookup = simple_uhash(HEALTH_LOOKUP_KEY);
+        hash_green = simple_uhash(HEALTH_GREEN_KEY);
+        hash_red = simple_uhash(HEALTH_RED_KEY);
+        hash_warn = simple_uhash(HEALTH_WARN_KEY);
+        hash_crit = simple_uhash(HEALTH_CRIT_KEY);
+        hash_exec = simple_uhash(HEALTH_EXEC_KEY);
+        hash_every = simple_uhash(HEALTH_EVERY_KEY);
+        hash_units = simple_hash(HEALTH_UNITS_KEY);
+        hash_info = simple_hash(HEALTH_INFO_KEY);
+    }
+
+    snprintfz(buffer, HEALTH_CONF_MAX_LINE, "%s/%s", path, filename);
+    FILE *fp = fopen(buffer, "r");
+    if(!fp) {
+        error("Health configuration cannot read file '%s'.", buffer);
+        return 0;
+    }
+
+    RRDCALC *rc = NULL;
+    RRDCALCTEMPLATE *rt = NULL;
+
+    size_t line = 0, append = 0;
+    char *s;
+    while((s = fgets(&buffer[append], (int)(HEALTH_CONF_MAX_LINE - append), fp)) || append) {
+        int stop_appending = !s;
+        line++;
+        // info("Line %zu of file '%s/%s': '%s'", line, path, filename, s);
+        s = trim(buffer);
+        if(!s) continue;
+        // info("Trimmed line %zu of file '%s/%s': '%s'", line, path, filename, s);
+
+        append = strlen(s);
+        if(!stop_appending && s[append - 1] == '\\') {
+            s[append - 1] = ' ';
+            append = &s[append] - buffer;
+            if(append < HEALTH_CONF_MAX_LINE)
+                continue;
+            else {
+                error("Health configuration has too long muli-line at line %zu of file '%s/%s'.", line, path, filename);
+            }
+        }
+        append = 0;
+
+        char *key = s;
+        while(*s && *s != ':') s++;
+        if(!*s) {
+            error("Health configuration has invalid line %zu of file '%s/%s'. It does not contain a ':'. Ignoring it.", line, path, filename);
+            continue;
+        }
+        *s = '\0';
+        s++;
+
+        char *value = s;
+        key = trim(key);
+        value = trim(value);
+
+        if(!key) {
+            error("Health configuration has invalid line %zu of file '%s/%s'. Keyword is empty. Ignoring it.", line, path, filename);
+            continue;
+        }
+
+        if(!value) {
+            error("Health configuration has invalid line %zu of file '%s/%s'. value is empty. Ignoring it.", line, path, filename);
+            continue;
+        }
+
+        // info("Health file '%s/%s', key '%s', value '%s'", path, filename, key, value);
+        uint32_t hash = simple_uhash(key);
+
+        if(hash == hash_alarm && !strcasecmp(key, HEALTH_ALARM_KEY)) {
+            if(rc && !rrdcalc_add_alarm_from_config(&localhost, rc))
+                rrdcalc_free(&localhost, rc);
+
+            if(rt) {
+                if (!rrdcalctemplate_add_template_from_config(&localhost, rt))
+                    rrdcalctemplate_free(&localhost, rt);
+                rt = NULL;
+            }
+
+            rc = callocz(1, sizeof(RRDCALC));
+            rc->name = strdupz(value);
+            rc->hash = simple_hash(rc->name);
+            rc->source = health_source_file(line, path, filename);
+            rc->green = NAN;
+            rc->red = NAN;
+            rc->value = NAN;
+            rc->old_value = NAN;
+
+            if(rrdvar_fix_name(rc->name))
+                error("Health configuration renamed alarm '%s' to '%s'", value, rc->name);
+        }
+        else if(hash == hash_template && !strcasecmp(key, HEALTH_TEMPLATE_KEY)) {
+            if(rc) {
+                if(!rrdcalc_add_alarm_from_config(&localhost, rc))
+                    rrdcalc_free(&localhost, rc);
+                rc = NULL;
+            }
+
+            if(rt && !rrdcalctemplate_add_template_from_config(&localhost, rt))
+                rrdcalctemplate_free(&localhost, rt);
+
+            rt = callocz(1, sizeof(RRDCALCTEMPLATE));
+            rt->name = strdupz(value);
+            rt->hash_name = simple_hash(rt->name);
+            rt->source = health_source_file(line, path, filename);
+            rt->green = NAN;
+            rt->red = NAN;
+
+            if(rrdvar_fix_name(rt->name))
+                error("Health configuration renamed template '%s' to '%s'", value, rt->name);
+        }
+        else if(rc) {
+            if(hash == hash_on && !strcasecmp(key, HEALTH_ON_KEY)) {
+                if(rc->chart) {
+                    if(strcmp(rc->chart, value))
+                        info("Health configuration at line %zu of file '%s/%s' for alarm '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rc->name, key, rc->chart, value, value);
+
+                    freez(rc->chart);
+                }
+                rc->chart = strdupz(value);
+                rc->hash_chart = simple_hash(rc->chart);
+            }
+            else if(hash == hash_lookup && !strcasecmp(key, HEALTH_LOOKUP_KEY)) {
+                health_parse_db_lookup(line, path, filename, value, &rc->group, &rc->after, &rc->before,
+                                       &rc->update_every,
+                                       &rc->options, &rc->dimensions);
+            }
+            else if(hash == hash_every && !strcasecmp(key, HEALTH_EVERY_KEY)) {
+                if(!health_parse_duration(value, &rc->update_every))
+                    info("Health configuration at line %zu of file '%s/%s' for alarm '%s' at key '%s' cannot parse duration: '%s'.",
+                         line, path, filename, rc->name, key, value);
+            }
+            else if(hash == hash_green && !strcasecmp(key, HEALTH_GREEN_KEY)) {
+                char *e;
+                rc->green = strtold(value, &e);
+                if(e && *e) {
+                    info("Health configuration at line %zu of file '%s/%s' for alarm '%s' at key '%s' leaves this string unmatched: '%s'.",
+                         line, path, filename, rc->name, key, e);
+                }
+            }
+            else if(hash == hash_red && !strcasecmp(key, HEALTH_RED_KEY)) {
+                char *e;
+                rc->red = strtold(value, &e);
+                if(e && *e) {
+                    info("Health configuration at line %zu of file '%s/%s' for alarm '%s' at key '%s' leaves this string unmatched: '%s'.",
+                         line, path, filename, rc->name, key, e);
+                }
+            }
+            else if(hash == hash_calc && !strcasecmp(key, HEALTH_CALC_KEY)) {
+                const char *failed_at = NULL;
+                int error = 0;
+                rc->calculation = expression_parse(value, &failed_at, &error);
+                if(!rc->calculation) {
+                    error("Health configuration at line %zu of file '%s/%s' for alarm '%s' at key '%s' has unparse-able expression '%s': %s at '%s'",
+                          line, path, filename, rc->name, key, value, expression_strerror(error), failed_at);
+                }
+            }
+            else if(hash == hash_warn && !strcasecmp(key, HEALTH_WARN_KEY)) {
+                const char *failed_at = NULL;
+                int error = 0;
+                rc->warning = expression_parse(value, &failed_at, &error);
+                if(!rc->warning) {
+                    error("Health configuration at line %zu of file '%s/%s' for alarm '%s' at key '%s' has unparse-able expression '%s': %s at '%s'",
+                          line, path, filename, rc->name, key, value, expression_strerror(error), failed_at);
+                }
+            }
+            else if(hash == hash_crit && !strcasecmp(key, HEALTH_CRIT_KEY)) {
+                const char *failed_at = NULL;
+                int error = 0;
+                rc->critical = expression_parse(value, &failed_at, &error);
+                if(!rc->critical) {
+                    error("Health configuration at line %zu of file '%s/%s' for alarm '%s' at key '%s' has unparse-able expression '%s': %s at '%s'",
+                          line, path, filename, rc->name, key, value, expression_strerror(error), failed_at);
+                }
+            }
+            else if(hash == hash_exec && !strcasecmp(key, HEALTH_EXEC_KEY)) {
+                if(rc->exec) {
+                    if(strcmp(rc->exec, value))
+                        info("Health configuration at line %zu of file '%s/%s' for alarm '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rc->name, key, rc->exec, value, value);
+
+                    freez(rc->exec);
+                }
+                rc->exec = strdupz(value);
+            }
+            else if(hash == hash_units && !strcasecmp(key, HEALTH_UNITS_KEY)) {
+                if(rc->units) {
+                    if(strcmp(rc->units, value))
+                        info("Health configuration at line %zu of file '%s/%s' for alarm '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rc->name, key, rc->units, value, value);
+
+                    freez(rc->units);
+                }
+                rc->units = strdupz(value);
+                strip_quotes(rc->units);
+            }
+            else if(hash == hash_info && !strcasecmp(key, HEALTH_INFO_KEY)) {
+                if(rc->info) {
+                    if(strcmp(rc->info, value))
+                        info("Health configuration at line %zu of file '%s/%s' for alarm '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rc->name, key, rc->info, value, value);
+
+                    freez(rc->info);
+                }
+                rc->info = strdupz(value);
+                strip_quotes(rc->info);
+            }
+            else {
+                error("Health configuration at line %zu of file '%s/%s' for alarm '%s' has unknown key '%s'.",
+                     line, path, filename, rc->name, key);
+            }
+        }
+        else if(rt) {
+            if(hash == hash_on && !strcasecmp(key, HEALTH_ON_KEY)) {
+                if(rt->context) {
+                    if(strcmp(rt->context, value))
+                        info("Health configuration at line %zu of file '%s/%s' for template '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rt->name, key, rt->context, value, value);
+
+                    freez(rt->context);
+                }
+                rt->context = strdupz(value);
+                rt->hash_context = simple_hash(rt->context);
+            }
+            else if(hash == hash_lookup && !strcasecmp(key, HEALTH_LOOKUP_KEY)) {
+                health_parse_db_lookup(line, path, filename, value, &rt->group, &rt->after, &rt->before,
+                                       &rt->update_every,
+                                       &rt->options, &rt->dimensions);
+            }
+            else if(hash == hash_every && !strcasecmp(key, HEALTH_EVERY_KEY)) {
+                if(!health_parse_duration(value, &rt->update_every))
+                    info("Health configuration at line %zu of file '%s/%s' for template '%s' at key '%s' cannot parse duration: '%s'.",
+                         line, path, filename, rt->name, key, value);
+            }
+            else if(hash == hash_green && !strcasecmp(key, HEALTH_GREEN_KEY)) {
+                char *e;
+                rt->green = strtold(value, &e);
+                if(e && *e) {
+                    info("Health configuration at line %zu of file '%s/%s' for template '%s' at key '%s' leaves this string unmatched: '%s'.",
+                         line, path, filename, rt->name, key, e);
+                }
+            }
+            else if(hash == hash_red && !strcasecmp(key, HEALTH_RED_KEY)) {
+                char *e;
+                rt->red = strtold(value, &e);
+                if(e && *e) {
+                    info("Health configuration at line %zu of file '%s/%s' for template '%s' at key '%s' leaves this string unmatched: '%s'.",
+                         line, path, filename, rt->name, key, e);
+                }
+            }
+            else if(hash == hash_calc && !strcasecmp(key, HEALTH_CALC_KEY)) {
+                const char *failed_at = NULL;
+                int error = 0;
+                rt->calculation = expression_parse(value, &failed_at, &error);
+                if(!rt->calculation) {
+                    error("Health configuration at line %zu of file '%s/%s' for template '%s' at key '%s' has unparse-able expression '%s': %s at '%s'",
+                          line, path, filename, rt->name, key, value, expression_strerror(error), failed_at);
+                }
+            }
+            else if(hash == hash_warn && !strcasecmp(key, HEALTH_WARN_KEY)) {
+                const char *failed_at = NULL;
+                int error = 0;
+                rt->warning = expression_parse(value, &failed_at, &error);
+                if(!rt->warning) {
+                    error("Health configuration at line %zu of file '%s/%s' for template '%s' at key '%s' has unparse-able expression '%s': %s at '%s'",
+                          line, path, filename, rt->name, key, value, expression_strerror(error), failed_at);
+                }
+            }
+            else if(hash == hash_crit && !strcasecmp(key, HEALTH_CRIT_KEY)) {
+                const char *failed_at = NULL;
+                int error = 0;
+                rt->critical = expression_parse(value, &failed_at, &error);
+                if(!rt->critical) {
+                    error("Health configuration at line %zu of file '%s/%s' for template '%s' at key '%s' has unparse-able expression '%s': %s at '%s'",
+                          line, path, filename, rt->name, key, value, expression_strerror(error), failed_at);
+                }
+            }
+            else if(hash == hash_exec && !strcasecmp(key, HEALTH_EXEC_KEY)) {
+                if(rt->exec) {
+                    if(strcmp(rt->exec, value))
+                        info("Health configuration at line %zu of file '%s/%s' for template '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rt->name, key, rt->exec, value, value);
+
+                    freez(rt->exec);
+                }
+                rt->exec = strdupz(value);
+            }
+            else if(hash == hash_units && !strcasecmp(key, HEALTH_UNITS_KEY)) {
+                if(rt->units) {
+                    if(strcmp(rt->units, value))
+                        info("Health configuration at line %zu of file '%s/%s' for template '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rt->name, key, rt->units, value, value);
+
+                    freez(rt->units);
+                }
+                rt->units = strdupz(value);
+                strip_quotes(rt->units);
+            }
+            else if(hash == hash_info && !strcasecmp(key, HEALTH_INFO_KEY)) {
+                if(rt->info) {
+                    if(strcmp(rt->info, value))
+                        info("Health configuration at line %zu of file '%s/%s' for template '%s' has key '%s' twice, once with value '%s' and later with value '%s'. Using ('%s').",
+                             line, path, filename, rt->name, key, rt->info, value, value);
+
+                    freez(rt->info);
+                }
+                rt->info = strdupz(value);
+                strip_quotes(rt->info);
+            }
+            else {
+                error("Health configuration at line %zu of file '%s/%s' for template '%s' has unknown key '%s'.",
+                      line, path, filename, rt->name, key);
+            }
+        }
+        else {
+            error("Health configuration at line %zu of file '%s/%s' has unknown key '%s'. Expected either '" HEALTH_ALARM_KEY "' or '" HEALTH_TEMPLATE_KEY "'.",
+                  line, path, filename, key);
+        }
+    }
+
+    if(rc && !rrdcalc_add_alarm_from_config(&localhost, rc))
+        rrdcalc_free(&localhost, rc);
+
+    if(rt && !rrdcalctemplate_add_template_from_config(&localhost, rt))
+        rrdcalctemplate_free(&localhost, rt);
+
+    fclose(fp);
+    return 1;
+}
+
+void health_readdir(const char *path) {
+    size_t pathlen = strlen(path);
+
+    debug(D_HEALTH, "Health configuration reading directory '%s'", path);
+
+    DIR *dir = opendir(path);
+    if (!dir) {
+        error("Health configuration cannot open directory '%s'.", path);
+        return;
+    }
+
+    struct dirent *de = NULL;
+    while ((de = readdir(dir))) {
+        size_t len = strlen(de->d_name);
+
+        if(de->d_type == DT_DIR
+           && (
+                   (de->d_name[0] == '.' && de->d_name[1] == '\0')
+                   || (de->d_name[0] == '.' && de->d_name[1] == '.' && de->d_name[2] == '\0')
+           ))
+            continue;
+
+        else if(de->d_type == DT_DIR) {
+            char *s = mallocz(pathlen + strlen(de->d_name) + 2);
+            strcpy(s, path);
+            strcat(s, "/");
+            strcat(s, de->d_name);
+            health_readdir(s);
+            freez(s);
+            continue;
+        }
+
+        else if((de->d_type == DT_LNK || de->d_type == DT_REG) &&
+                len > 5 && !strcmp(&de->d_name[len - 5], ".conf")) {
+            health_readfile(path, de->d_name);
+        }
+    }
+
+    closedir(dir);
+}
+
+static inline char *health_config_dir(void) {
+    char buffer[FILENAME_MAX + 1];
+    snprintfz(buffer, FILENAME_MAX, "%s/health.d", config_get("global", "config directory", CONFIG_DIR));
+    return config_get("health", "health configuration directory", buffer);
+}
+
+void health_init(void) {
+    debug(D_HEALTH, "Health configuration initializing");
+
+    if(!(health_enabled = config_get_boolean("health", "enabled", 1))) {
+        debug(D_HEALTH, "Health is disabled.");
+        return;
+    }
+
+    char *path = health_config_dir();
+
+    {
+        char buffer[FILENAME_MAX + 1];
+        snprintfz(buffer, FILENAME_MAX, "%s/alarm-email.sh", config_get("global", "plugins directory", PLUGINS_DIR));
+        health_default_exec = config_get("health", "script to execute on alarm", buffer);
+    }
+
+    long n = config_get_number("health", "in memory max health log entries", (long)localhost.health_log.max);
+    if(n < 2) {
+        error("Health configuration has invalid max log entries %ld. Using default %u", n, localhost.health_log.max);
+        config_set_number("health", "in memory max health log entries", (long)localhost.health_log.max);
+    }
+    else localhost.health_log.max = (unsigned int)n;
+
+    rrdhost_rwlock(&localhost);
+    health_readdir(path);
+    rrdhost_unlock(&localhost);
+}
+
+// ----------------------------------------------------------------------------
+// JSON generation
+
+static inline void health_string2json(BUFFER *wb, const char *prefix, const char *label, const char *value, const char *suffix) {
+    if(value && *value)
+        buffer_sprintf(wb, "%s\"%s\":\"%s\"%s", prefix, label, value, suffix);
+    else
+        buffer_sprintf(wb, "%s\"%s\":null%s", prefix, label, suffix);
+}
+
+static inline void health_alarm_entry2json_nolock(BUFFER *wb, ALARM_ENTRY *ae) {
+    buffer_sprintf(wb, "\n\t{\n"
+                           "\t\t\"id\":%u,\n"
+                           "\t\t\"name\":\"%s\",\n"
+                           "\t\t\"chart\":\"%s\",\n"
+                           "\t\t\"family\":\"%s\",\n"
+                           "\t\t\"processed\":%s,\n"
+                           "\t\t\"updated\":%s,\n"
+                           "\t\t\"exec_run\":%s,\n"
+                           "\t\t\"exec_failed\":%s,\n"
+                           "\t\t\"exec\":\"%s\",\n"
+                           "\t\t\"exec_code\":%d,\n"
+                           "\t\t\"source\":\"%s\",\n"
+                           "\t\t\"units\":\"%s\",\n"
+                           "\t\t\"info\":\"%s\",\n"
+                           "\t\t\"when\":%lu,\n"
+                           "\t\t\"duration\":%lu,\n"
+                           "\t\t\"non_clear_duration\":%lu,\n"
+                           "\t\t\"status\":\"%s\",\n"
+                           "\t\t\"old_status\":\"%s\",\n",
+                   ae->id,
+                   ae->name,
+                   ae->chart,
+                   ae->family,
+                   (ae->notifications & HEALTH_ENTRY_NOTIFICATIONS_PROCESSED)?"true":"false",
+                   (ae->notifications & HEALTH_ENTRY_NOTIFICATIONS_UPDATED)?"true":"false",
+                   (ae->notifications & HEALTH_ENTRY_NOTIFICATIONS_EXEC_RUN)?"true":"false",
+                   (ae->notifications & HEALTH_ENTRY_NOTIFICATIONS_EXEC_FAILED)?"true":"false",
+                   ae->exec?ae->exec:health_default_exec,
+                   ae->exec_code,
+                   ae->source,
+                   ae->units?ae->units:"",
+                   ae->info?ae->info:"",
+                   (unsigned long)ae->when,
+                   (unsigned long)ae->duration,
+                   (unsigned long)ae->non_clear_duration,
+                   rrdcalc_status2string(ae->new_status),
+                   rrdcalc_status2string(ae->old_status)
+    );
+
+    buffer_strcat(wb, "\t\t\"value\":");
+    buffer_rrd_value(wb, ae->new_value);
+    buffer_strcat(wb, ",\n");
+
+    buffer_strcat(wb, "\t\t\"old_value\":");
+    buffer_rrd_value(wb, ae->old_value);
+    buffer_strcat(wb, "\n");
+
+    buffer_strcat(wb, "\t}");
+}
+
+void health_alarm_log2json(RRDHOST *host, BUFFER *wb) {
+    pthread_rwlock_rdlock(&host->health_log.alarm_log_rwlock);
+
+    buffer_strcat(wb, "[");
+
+    unsigned int max = host->health_log.max;
+    unsigned int count = 0;
+    ALARM_ENTRY *ae;
+    for(ae = host->health_log.alarms; ae && count < max ; count++, ae = ae->next) {
+        if(likely(count)) buffer_strcat(wb, ",");
+        health_alarm_entry2json_nolock(wb, ae);
+    }
+
+    buffer_strcat(wb, "\n]\n");
+
+    pthread_rwlock_unlock(&host->health_log.alarm_log_rwlock);
+}
+
+static inline void health_rrdcalc2json_nolock(BUFFER *wb, RRDCALC *rc) {
+    buffer_sprintf(wb,
+           "\t\t\"%s.%s\": {\n"
+                   "\t\t\t\"name\": \"%s\",\n"
+                   "\t\t\t\"chart\": \"%s\",\n"
+                   "\t\t\t\"family\": \"%s\",\n"
+                   "\t\t\t\"active\": %s,\n"
+                   "\t\t\t\"exec\": \"%s\",\n"
+                   "\t\t\t\"source\": \"%s\",\n"
+                   "\t\t\t\"units\": \"%s\",\n"
+                   "\t\t\t\"info\": \"%s\",\n"
+				   "\t\t\t\"status\": \"%s\",\n"
+                   "\t\t\t\"last_status_change\": %lu,\n"
+                   "\t\t\t\"last_updated\": %lu,\n"
+                   "\t\t\t\"next_update\": %lu,\n"
+                   "\t\t\t\"update_every\": %d,\n"
+            , rc->chart, rc->name
+            , rc->name
+            , rc->chart
+            , (rc->rrdset && rc->rrdset->family)?rc->rrdset->family:""
+            , (rc->rrdset)?"true":"false"
+            , rc->exec?rc->exec:health_default_exec
+            , rc->source
+            , rc->units?rc->units:""
+            , rc->info?rc->info:""
+            , rrdcalc_status2string(rc->status)
+            , (unsigned long)rc->last_status_change
+            , (unsigned long)rc->last_updated
+            , (unsigned long)rc->next_update
+            , rc->update_every
+    );
+
+    if(RRDCALC_HAS_DB_LOOKUP(rc)) {
+        if(rc->dimensions && *rc->dimensions)
+            health_string2json(wb, "\t\t\t", "lookup_dimensions", rc->dimensions, ",\n");
+
+        buffer_sprintf(wb,
+                       "\t\t\t\"db_after\": %lu,\n"
+                       "\t\t\t\"db_before\": %lu,\n"
+                       "\t\t\t\"lookup_method\": \"%s\",\n"
+                       "\t\t\t\"lookup_after\": %d,\n"
+                       "\t\t\t\"lookup_before\": %d,\n"
+                       "\t\t\t\"lookup_options\": \"",
+                       (unsigned long) rc->db_after,
+                       (unsigned long) rc->db_before,
+                       group_method2string(rc->group),
+                       rc->after,
+                       rc->before
+        );
+        buffer_data_options2string(wb, rc->options);
+        buffer_strcat(wb, "\",\n");
+    }
+
+    if(rc->calculation) {
+        health_string2json(wb, "\t\t\t", "calc", rc->calculation->source, ",\n");
+        health_string2json(wb, "\t\t\t", "calc_parsed", rc->calculation->parsed_as, ",\n");
+    }
+
+    if(rc->warning) {
+        health_string2json(wb, "\t\t\t", "warn", rc->warning->source, ",\n");
+        health_string2json(wb, "\t\t\t", "warn_parsed", rc->warning->parsed_as, ",\n");
+    }
+
+    if(rc->critical) {
+        health_string2json(wb, "\t\t\t", "crit", rc->critical->source, ",\n");
+        health_string2json(wb, "\t\t\t", "crit_parsed", rc->critical->parsed_as, ",\n");
+    }
+
+    buffer_strcat(wb, "\t\t\t\"green\":");
+    buffer_rrd_value(wb, rc->green);
+    buffer_strcat(wb, ",\n");
+
+    buffer_strcat(wb, "\t\t\t\"red\":");
+    buffer_rrd_value(wb, rc->red);
+    buffer_strcat(wb, ",\n");
+
+    buffer_strcat(wb, "\t\t\t\"value\":");
+    buffer_rrd_value(wb, rc->value);
+    buffer_strcat(wb, "\n");
+
+    buffer_strcat(wb, "\t\t}");
+}
+
+//void health_rrdcalctemplate2json_nolock(BUFFER *wb, RRDCALCTEMPLATE *rt) {
+//
+//}
+
+void health_alarms2json(RRDHOST *host, BUFFER *wb, int all) {
+    int i;
+    rrdhost_rdlock(&localhost);
+
+    buffer_strcat(wb, "{\n\t\"alarms\": {\n");
+    RRDCALC *rc;
+    for(i = 0, rc = host->alarms; rc ; rc = rc->next) {
+        if(!rc->rrdset)
+            continue;
+
+        if(!all && !(rc->status == RRDCALC_STATUS_WARNING || rc->status == RRDCALC_STATUS_CRITICAL))
+            continue;
+
+        if(likely(i)) buffer_strcat(wb, ",\n");
+        health_rrdcalc2json_nolock(wb, rc);
+        i++;
+    }
+
+//    buffer_strcat(wb, "\n\t},\n\t\"templates\": {");
+
+//    RRDCALCTEMPLATE *rt;
+//    for(rt = host->templates; rt ; rt = rt->next)
+//        health_rrdcalctemplate2json_nolock(wb, rt);
+
+    buffer_sprintf(wb, "\n\t},\n\t\"now\": %lu\n}\n", (unsigned long)time(NULL));
+    rrdhost_unlock(&localhost);
+}
+
+
+// ----------------------------------------------------------------------------
+// re-load health configuration
+
+static inline void health_free_all_nolock(RRDHOST *host) {
+    while(host->templates)
+        rrdcalctemplate_free(host, host->templates);
+
+    while(host->alarms)
+        rrdcalc_free(host, host->alarms);
+}
+
+void health_reload(void) {
+    if(!health_enabled) {
+        error("Health reload is requested, but health is not enabled.");
+        return;
+    }
+
+    char *path = health_config_dir();
+
+    rrdhost_rwlock(&localhost);
+    health_free_all_nolock(&localhost);
+    rrdhost_unlock(&localhost);
+
+    RRDSET *st;
+    for(st = localhost.rrdset_root; st ; st = st->next) {
+        st->green = NAN;
+        st->red = NAN;
+    }
+
+    rrdhost_rwlock(&localhost);
+    health_readdir(path);
+    rrdhost_unlock(&localhost);
+
+    for(st = localhost.rrdset_root; st ; st = st->next) {
+        rrdhost_rwlock(&localhost);
+
+        rrdsetcalc_link_matching(st);
+        rrdcalctemplate_link_matching(st);
+
+        rrdhost_unlock(&localhost);
+    }
+}
+
+
+// ----------------------------------------------------------------------------
+// health main thread and friends
+
+static inline int rrdcalc_isrunnable(RRDCALC *rc, time_t now, time_t *next_run) {
+    if (unlikely(!rc->rrdset)) {
+        debug(D_HEALTH, "Health not running alarm '%s.%s'. It is not linked to a chart.", rc->chart?rc->chart:"NOCHART", rc->name);
+        return 0;
+    }
+
+    if (unlikely(!rc->update_every)) {
+        debug(D_HEALTH, "Health not running alarm '%s.%s'. It does not have an update frequency", rc->chart?rc->chart:"NOCHART", rc->name);
+        return 0;
+    }
+
+    if (unlikely(rc->next_update > now)) {
+        if (*next_run > rc->next_update)
+            *next_run = rc->next_update;
+
+        debug(D_HEALTH, "Health not examining alarm '%s.%s' yet (will do in %d secs).", rc->chart?rc->chart:"NOCHART", rc->name, (int) (rc->next_update - now));
+        return 0;
+    }
+
+    return 1;
+}
+
+static inline int rrdcalc_value2status(calculated_number n) {
+    if(isnan(n)) return RRDCALC_STATUS_UNDEFINED;
+    if(n) return RRDCALC_STATUS_RAISED;
+    return RRDCALC_STATUS_CLEAR;
+}
+
+static inline void health_alarm_execute(ALARM_ENTRY *ae) {
+    if(ae->old_status == RRDCALC_STATUS_UNINITIALIZED && ae->new_status == RRDCALC_STATUS_CLEAR)
+        return;
+
+    char buffer[FILENAME_MAX + 1];
+    pid_t command_pid;
+
+    const char *exec = ae->exec;
+    if(!exec) exec = health_default_exec;
+
+    snprintfz(buffer, FILENAME_MAX, "exec %s '%s' '%s' '%s' '%s' '%s' '%0.0Lf' '%0.0Lf' '%s' '%u' '%u' '%s' '%s'",
+              exec,
+              ae->name,
+              ae->chart?ae->chart:"NOCAHRT",
+              ae->family?ae->family:"NOFAMILY",
+              rrdcalc_status2string(ae->new_status),
+              rrdcalc_status2string(ae->old_status),
+              ae->new_value,
+              ae->old_value,
+              ae->source?ae->source:"UNKNOWN",
+              (uint32_t)ae->duration,
+              (uint32_t)ae->non_clear_duration,
+              ae->units?ae->units:"",
+              ae->info?ae->info:""
+    );
+
+    ae->notifications |= HEALTH_ENTRY_NOTIFICATIONS_EXEC_RUN;
+
+    debug(D_HEALTH, "executing command '%s'", buffer);
+    FILE *fp = mypopen(buffer, &command_pid);
+    if(!fp) {
+        error("HEALTH: Cannot popen(\"%s\", \"r\").", buffer);
+        return;
+    }
+    debug(D_HEALTH, "HEALTH reading from command");
+    char *s = fgets(buffer, FILENAME_MAX, fp);
+    (void)s;
+    debug(D_HEALTH, "HEALTH closing command");
+    ae->exec_code = mypclose(fp, command_pid);
+    debug(D_HEALTH, "done executing command - returned with code %d", ae->exec_code);
+
+    if(ae->exec_code != 0)
+        ae->notifications |= HEALTH_ENTRY_NOTIFICATIONS_EXEC_FAILED;
+}
+
+static inline void health_process_notifications(ALARM_ENTRY *ae) {
+    info("Health alarm '%s.%s' = %0.2Lf - changed status from %s to %s",
+         ae->chart?ae->chart:"NOCHART", ae->name,
+         ae->new_value,
+         rrdcalc_status2string(ae->old_status),
+         rrdcalc_status2string(ae->new_status)
+    );
+
+    health_alarm_execute(ae);
+}
+
+static inline void health_alarm_log(RRDHOST *host, time_t when,
+                const char *name, const char *chart, const char *family,
+                const char *exec, time_t duration,
+                calculated_number old_value, calculated_number new_value,
+                int old_status, int new_status,
+                const char *source,
+                const char *units,
+                const char *info
+) {
+    ALARM_ENTRY *ae = callocz(1, sizeof(ALARM_ENTRY));
+    ae->name = strdupz(name);
+    ae->hash_name = simple_hash(ae->name);
+
+    if(chart) {
+        ae->chart = strdupz(chart);
+        ae->hash_chart = simple_hash(ae->chart);
+    }
+
+    if(family)
+        ae->family = strdupz(family);
+
+    if(exec) ae->exec = strdupz(exec);
+    if(source) ae->source = strdupz(source);
+    if(units) ae->units = strdupz(units);
+    if(info) ae->info = strdupz(info);
+
+    ae->id = host->health_log.nextid++;
+    ae->when = when;
+    ae->old_value = old_value;
+    ae->new_value = new_value;
+    ae->old_status = old_status;
+    ae->new_status = new_status;
+    ae->duration = duration;
+
+    if(ae->old_status == RRDCALC_STATUS_WARNING || ae->old_status == RRDCALC_STATUS_CRITICAL)
+        ae->non_clear_duration += ae->duration;
+
+    // link it
+    pthread_rwlock_wrlock(&host->health_log.alarm_log_rwlock);
+    ae->next = host->health_log.alarms;
+    host->health_log.alarms = ae;
+    host->health_log.count++;
+    pthread_rwlock_unlock(&host->health_log.alarm_log_rwlock);
+
+    // match previous alarms
+    pthread_rwlock_rdlock(&host->health_log.alarm_log_rwlock);
+    ALARM_ENTRY *t;
+    for(t = host->health_log.alarms ; t ; t = t->next) {
+        if(t != ae &&
+                t->hash_name == ae->hash_name &&
+                t->hash_chart == ae->hash_chart &&
+                !strcmp(t->name, ae->name) &&
+                t->chart && ae->chart && !strcmp(t->chart, ae->chart)) {
+
+            if(!(t->notifications & HEALTH_ENTRY_NOTIFICATIONS_UPDATED) && !t->updated_by) {
+                t->notifications |= HEALTH_ENTRY_NOTIFICATIONS_UPDATED;
+                t->updated_by = ae;
+
+                if((t->new_status == RRDCALC_STATUS_WARNING || t->new_status == RRDCALC_STATUS_CRITICAL) &&
+                   (t->old_status == RRDCALC_STATUS_WARNING || t->old_status == RRDCALC_STATUS_CRITICAL))
+                    ae->non_clear_duration += t->non_clear_duration;
+            }
+            else {
+                // no need to continue
+                break;
+            }
+        }
+    }
+    pthread_rwlock_unlock(&host->health_log.alarm_log_rwlock);
+}
+
+static inline void health_alarm_log_process(RRDHOST *host) {
+    static uint32_t last_processed = 0;
+    ALARM_ENTRY *ae;
+
+    pthread_rwlock_rdlock(&host->health_log.alarm_log_rwlock);
+
+    for(ae = host->health_log.alarms; ae ;ae = ae->next) {
+        if(last_processed >= ae->id) break;
+
+        if(!(ae->notifications & HEALTH_ENTRY_NOTIFICATIONS_PROCESSED) &&
+                !(ae->notifications & HEALTH_ENTRY_NOTIFICATIONS_UPDATED)) {
+            ae->notifications |= HEALTH_ENTRY_NOTIFICATIONS_PROCESSED;
+            health_process_notifications(ae);
+        }
+    }
+
+    if(host->health_log.alarms)
+        last_processed = host->health_log.alarms->id;
+
+    pthread_rwlock_unlock(&host->health_log.alarm_log_rwlock);
+
+    if(host->health_log.count <= host->health_log.max)
+        return;
+
+    // cleanup excess entries in the log
+    pthread_rwlock_wrlock(&host->health_log.alarm_log_rwlock);
+
+    ALARM_ENTRY *last = NULL;
+    unsigned int count = host->health_log.max;
+    for(ae = host->health_log.alarms; ae && count ; count--, last = ae, ae = ae->next) ;
+
+    if(ae && last && last->next == ae)
+        last->next = NULL;
+    else
+        ae = NULL;
+
+    while(ae) {
+        ALARM_ENTRY *t = ae->next;
+
+        freez(ae->name);
+        freez(ae->chart);
+        freez(ae->family);
+        freez(ae->exec);
+        freez(ae->source);
+        freez(ae->units);
+        freez(ae->info);
+        freez(ae);
+
+        ae = t;
+    }
+
+    pthread_rwlock_unlock(&host->health_log.alarm_log_rwlock);
+}
+
+void *health_main(void *ptr) {
+    (void)ptr;
+
+    info("HEALTH thread created with task id %d", gettid());
+
+    if(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL) != 0)
+        error("Cannot set pthread cancel type to DEFERRED.");
+
+    if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
+        error("Cannot set pthread cancel state to ENABLE.");
+
+    int min_run_every = (int)config_get_number("health", "run at least every seconds", 10);
+    if(min_run_every < 1) min_run_every = 1;
+
+    BUFFER *wb = buffer_create(100);
+
+    unsigned int loop = 0;
+    while(health_enabled) {
+        loop++;
+        debug(D_HEALTH, "Health monitoring iteration no %u started", loop);
+
+        int oldstate, runnable = 0;
+        time_t now = time(NULL);
+        time_t next_run = now + min_run_every;
+        RRDCALC *rc;
+
+        if (unlikely(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate) != 0))
+            error("Cannot set pthread cancel state to DISABLE.");
+
+        rrdhost_rdlock(&localhost);
+
+        // the first loop is to lookup values from the db
+        for (rc = localhost.alarms; rc; rc = rc->next) {
+            if (unlikely(!rrdcalc_isrunnable(rc, now, &next_run)))
+                continue;
+
+            runnable++;
+            rc->old_value = rc->value;
+
+            // 1. if there is database lookup, do it
+            // 2. if there is calculation expression, run it
+
+            if (unlikely(RRDCALC_HAS_DB_LOOKUP(rc))) {
+                time_t old_db_timestamp = rc->db_before;
+                int value_is_null = 0;
+
+                int ret = rrd2value(rc->rrdset, wb, &rc->value,
+                                    rc->dimensions, 1, rc->after, rc->before, rc->group,
+                                    rc->options, &rc->db_after, &rc->db_before, &value_is_null);
+
+                if (unlikely(ret != 200)) {
+                    // database lookup failed
+                    rc->value = NAN;
+
+                    debug(D_HEALTH, "Health alarm '%s.%s': database lookup returned error %d", rc->chart?rc->chart:"NOCHART", rc->name, ret);
+
+                    if (unlikely(!(rc->rrdcalc_flags & RRDCALC_FLAG_DB_ERROR))) {
+                        rc->rrdcalc_flags |= RRDCALC_FLAG_DB_ERROR;
+                        error("Health alarm '%s.%s': database lookup returned error %d", rc->chart?rc->chart:"NOCHART", rc->name, ret);
+                    }
+                }
+                else if (unlikely(rc->rrdcalc_flags & RRDCALC_FLAG_DB_ERROR))
+                    rc->rrdcalc_flags &= ~RRDCALC_FLAG_DB_ERROR;
+
+                if (unlikely(old_db_timestamp == rc->db_before)) {
+                    // database is stale
+
+                    debug(D_HEALTH, "Health alarm '%s.%s': database is stale", rc->chart?rc->chart:"NOCHART", rc->name);
+
+                    if (unlikely(!(rc->rrdcalc_flags & RRDCALC_FLAG_DB_STALE))) {
+                        rc->rrdcalc_flags |= RRDCALC_FLAG_DB_STALE;
+                        error("Health alarm '%s.%s': database is stale", rc->chart?rc->chart:"NOCHART", rc->name);
+                    }
+                }
+                else if (unlikely(rc->rrdcalc_flags & RRDCALC_FLAG_DB_STALE))
+                    rc->rrdcalc_flags &= ~RRDCALC_FLAG_DB_STALE;
+
+                if (unlikely(value_is_null)) {
+                    // collected value is null
+
+                    rc->value = NAN;
+
+                    debug(D_HEALTH, "Health alarm '%s.%s': database lookup returned empty value (possibly value is not collected yet)",
+                          rc->chart?rc->chart:"NOCHART", rc->name);
+
+                    if (unlikely(!(rc->rrdcalc_flags & RRDCALC_FLAG_DB_NAN))) {
+                        rc->rrdcalc_flags |= RRDCALC_FLAG_DB_NAN;
+                        error("Health alarm '%s.%s': database lookup returned empty value (possibly value is not collected yet)",
+                              rc->chart?rc->chart:"NOCHART", rc->name);
+                    }
+                }
+                else if (unlikely(rc->rrdcalc_flags & RRDCALC_FLAG_DB_NAN))
+                    rc->rrdcalc_flags &= ~RRDCALC_FLAG_DB_NAN;
+
+                debug(D_HEALTH, "Health alarm '%s.%s': database lookup gave value "
+                        CALCULATED_NUMBER_FORMAT, rc->chart?rc->chart:"NOCHART", rc->name, rc->value);
+            }
+
+            if(unlikely(rc->calculation)) {
+                if (unlikely(!expression_evaluate(rc->calculation))) {
+                    // calculation failed
+
+                    rc->value = NAN;
+
+                    debug(D_HEALTH, "Health alarm '%s.%s': failed to evaluate calculation with error: %s",
+                          rc->chart?rc->chart:"NOCHART", rc->name, buffer_tostring(rc->calculation->error_msg));
+
+                    if (unlikely(!(rc->rrdcalc_flags & RRDCALC_FLAG_CALC_ERROR))) {
+                        rc->rrdcalc_flags |= RRDCALC_FLAG_CALC_ERROR;
+                        error("Health alarm '%s.%s': failed to evaluate calculation with error: %s",
+                              rc->chart?rc->chart:"NOCHART", rc->name, buffer_tostring(rc->calculation->error_msg));
+                    }
+                }
+                else {
+                    if (unlikely(rc->rrdcalc_flags & RRDCALC_FLAG_CALC_ERROR))
+                        rc->rrdcalc_flags &= ~RRDCALC_FLAG_CALC_ERROR;
+
+                    debug(D_HEALTH, "Health alarm '%s.%s': calculation expression gave value "
+                            CALCULATED_NUMBER_FORMAT
+                            ": %s (source: %s)",
+                          rc->chart?rc->chart:"NOCHART", rc->name,
+                          rc->calculation->result,
+                          buffer_tostring(rc->calculation->error_msg),
+                          rc->source
+                    );
+
+                    rc->value = rc->calculation->result;
+                }
+            }
+        }
+        rrdhost_unlock(&localhost);
+
+        if (runnable) {
+            rrdhost_rdlock(&localhost);
+
+            for (rc = localhost.alarms; rc; rc = rc->next) {
+                if (unlikely(!rrdcalc_isrunnable(rc, now, &next_run)))
+                    continue;
+
+                int warning_status  = RRDCALC_STATUS_UNDEFINED;
+                int critical_status = RRDCALC_STATUS_UNDEFINED;
+
+                if(unlikely(rc->warning)) {
+                    if(unlikely(!expression_evaluate(rc->warning))) {
+                        // calculation failed
+
+                        debug(D_HEALTH, "Health alarm '%s.%s': warning expression failed with error: %s",
+                              rc->chart?rc->chart:"NOCHART", rc->name, buffer_tostring(rc->warning->error_msg));
+
+                        if (unlikely(!(rc->rrdcalc_flags & RRDCALC_FLAG_WARN_ERROR))) {
+                            rc->rrdcalc_flags |= RRDCALC_FLAG_WARN_ERROR;
+                            error("Health alarm '%s.%s': warning expression failed with error: %s",
+                                  rc->chart?rc->chart:"NOCHART", rc->name, buffer_tostring(rc->warning->error_msg));
+                        }
+                    }
+                    else {
+                        if(unlikely(rc->rrdcalc_flags & RRDCALC_FLAG_WARN_ERROR))
+                            rc->rrdcalc_flags &= ~RRDCALC_FLAG_WARN_ERROR;
+
+                        debug(D_HEALTH, "Health alarm '%s.%s': warning expression gave value "
+                                CALCULATED_NUMBER_FORMAT
+                                ": %s (source: %s)",
+                              rc->chart?rc->chart:"NOCHART", rc->name,
+                              rc->warning->result,
+                              buffer_tostring(rc->warning->error_msg),
+                              rc->source
+                        );
+
+                        warning_status = rrdcalc_value2status(rc->warning->result);
+                    }
+                }
+
+                if(unlikely(rc->critical)) {
+                    if(unlikely(!expression_evaluate(rc->critical))) {
+                        // calculation failed
+
+                        debug(D_HEALTH, "Health alarm '%s.%s': critical expression failed with error: %s",
+                              rc->chart?rc->chart:"NOCHART", rc->name, buffer_tostring(rc->critical->error_msg));
+
+                        if (unlikely(!(rc->rrdcalc_flags & RRDCALC_FLAG_CRIT_ERROR))) {
+                            rc->rrdcalc_flags |= RRDCALC_FLAG_CRIT_ERROR;
+                            error("Health alarm '%s.%s': critical expression failed with error: %s",
+                                  rc->chart?rc->chart:"NOCHART", rc->name, buffer_tostring(rc->critical->error_msg));
+                        }
+                    }
+                    else {
+                        if(unlikely(rc->rrdcalc_flags & RRDCALC_FLAG_CRIT_ERROR))
+                            rc->rrdcalc_flags &= ~RRDCALC_FLAG_CRIT_ERROR;
+
+                        debug(D_HEALTH, "Health alarm '%s.%s': critical expression gave value "
+                                CALCULATED_NUMBER_FORMAT
+                                ": %s (source: %s)",
+                              rc->chart?rc->chart:"NOCHART", rc->name,
+                              rc->critical->result,
+                              buffer_tostring(rc->critical->error_msg),
+                              rc->source
+                        );
+
+                        critical_status = rrdcalc_value2status(rc->critical->result);
+                    }
+                }
+
+                int status = RRDCALC_STATUS_UNDEFINED;
+
+                switch(warning_status) {
+                    case RRDCALC_STATUS_CLEAR:
+                        status = RRDCALC_STATUS_CLEAR;
+                        break;
+
+                    case RRDCALC_STATUS_RAISED:
+                        status = RRDCALC_STATUS_WARNING;
+                        break;
+
+                    default:
+                        break;
+                }
+
+                switch(critical_status) {
+                    case RRDCALC_STATUS_CLEAR:
+                        if(status == RRDCALC_STATUS_UNDEFINED)
+                            status = RRDCALC_STATUS_CLEAR;
+                        break;
+
+                    case RRDCALC_STATUS_RAISED:
+                        status = RRDCALC_STATUS_CRITICAL;
+                        break;
+
+                    default:
+                        break;
+                }
+
+                if(status != rc->status) {
+                    health_alarm_log(&localhost, time(NULL), rc->name, rc->rrdset->id, rc->rrdset->family, rc->exec, now - rc->last_status_change, rc->old_value, rc->value, rc->status, status, rc->source, rc->units, rc->info);
+                    rc->last_status_change = now;
+                    rc->status = status;
+                }
+
+                rc->last_updated = now;
+                rc->next_update = now + rc->update_every;
+
+                if (next_run > rc->next_update)
+                    next_run = rc->next_update;
+            }
+
+            rrdhost_unlock(&localhost);
+        }
+
+        if (unlikely(pthread_setcancelstate(oldstate, NULL) != 0))
+            error("Cannot set pthread cancel state to RESTORE (%d).", oldstate);
+
+        // execute notifications
+        // and cleanup
+        health_alarm_log_process(&localhost);
+
+        now = time(NULL);
+        if(now < next_run) {
+            debug(D_HEALTH, "Health monitoring iteration no %u done. Next iteration in %d secs",
+                  loop, (int) (next_run - now));
+            sleep_usec(1000000 * (unsigned long long) (next_run - now));
+        }
+        else {
+            debug(D_HEALTH, "Health monitoring iteration no %u done. Next iteration now", loop);
+        }
+    }
+
+    buffer_free(wb);
+
+    info("HEALTH thread exiting");
+    pthread_exit(NULL);
+    return NULL;
+}