Merging upstream version 1.11.0+dfsg.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 0 insertions, 969 deletions

diff --git a/src/backends.c b/src/backends.c
deleted file mode 100644
index 1360638f2..000000000
--- a/src/backends.c
+++ /dev/null
@@ -1,969 +0,0 @@
-#include "common.h"
-
-// ----------------------------------------------------------------------------
-// How backends work in netdata:
-//
-// 1. There is an independent thread that runs at the required interval
-//    (for example, once every 10 seconds)
-//
-// 2. Every time it wakes, it calls the backend formatting functions to build
-//    a buffer of data. This is a very fast, memory only operation.
-//
-// 3. If the buffer already includes data, the new data are appended.
-//    If the buffer becomes too big, because the data cannot be sent, a
-//    log is written and the buffer is discarded.
-//
-// 4. Then it tries to send all the data. It blocks until all the data are sent
-//    or the socket returns an error.
-//    If the time required for this is above the interval, it starts skipping
-//    intervals, but the calculated values include the entire database, without
-//    gaps (it remembers the timestamps and continues from where it stopped).
-//
-// 5. repeats the above forever.
-//
-
-const char *backend_prefix = "netdata";
-int backend_send_names = 1;
-int backend_update_every = 10;
-uint32_t backend_options = BACKEND_SOURCE_DATA_AVERAGE;
-
-// ----------------------------------------------------------------------------
-// helper functions for backends
-
-static inline size_t backend_name_copy(char *d, const char *s, size_t usable) {
-    size_t n;
-
-    for(n = 0; *s && n < usable ; d++, s++, n++) {
-        char c = *s;
-
-        if(c != '.' && !isalnum(c)) *d = '_';
-        else *d = c;
-    }
-    *d = '\0';
-
-    return n;
-}
-
-// calculate the SUM or AVERAGE of a dimension, for any timeframe
-// may return NAN if the database does not have any value in the give timeframe
-
-inline calculated_number backend_calculate_value_from_stored_data(
-          RRDSET *st                // the chart
-        , RRDDIM *rd                // the dimension
-        , time_t after              // the start timestamp
-        , time_t before             // the end timestamp
-        , uint32_t options          // BACKEND_SOURCE_* bitmap
-        , time_t *first_timestamp   // the first point of the database used in this response
-        , time_t *last_timestamp    // the timestamp that should be reported to backend
-) {
-    RRDHOST *host = st->rrdhost;
-
-    // find the edges of the rrd database for this chart
-    time_t first_t = rrdset_first_entry_t(st);
-    time_t last_t  = rrdset_last_entry_t(st);
-    time_t update_every = st->update_every;
-
-    // step back a little, to make sure we have complete data collection
-    // for all metrics
-    after  -= update_every * 2;
-    before -= update_every * 2;
-
-    // align the time-frame
-    after  = after  - (after  % update_every);
-    before = before - (before % update_every);
-
-    // for before, loose another iteration
-    // the latest point will be reported the next time
-    before -= update_every;
-
-    if(unlikely(after > before))
-        // this can happen when update_every > before - after
-        after = before;
-
-    if(unlikely(after < first_t))
-        after = first_t;
-
-    if(unlikely(before > last_t))
-        before = last_t;
-
-    if(unlikely(before < first_t || after > last_t)) {
-        // the chart has not been updated in the wanted timeframe
-        debug(D_BACKEND, "BACKEND: %s.%s.%s: aligned timeframe %lu to %lu is outside the chart's database range %lu to %lu",
-              host->hostname, st->id, rd->id,
-              (unsigned long)after, (unsigned long)before,
-              (unsigned long)first_t, (unsigned long)last_t
-        );
-        return NAN;
-    }
-
-    *first_timestamp = after;
-    *last_timestamp = before;
-
-    size_t counter = 0;
-    calculated_number sum = 0;
-
-    long    start_at_slot = rrdset_time2slot(st, before),
-            stop_at_slot  = rrdset_time2slot(st, after),
-            slot, stop_now = 0;
-
-    for(slot = start_at_slot; !stop_now ; slot--) {
-
-        if(unlikely(slot < 0)) slot = st->entries - 1;
-        if(unlikely(slot == stop_at_slot)) stop_now = 1;
-
-        storage_number n = rd->values[slot];
-
-        if(unlikely(!does_storage_number_exist(n))) {
-            // not collected
-            continue;
-        }
-
-        calculated_number value = unpack_storage_number(n);
-        sum += value;
-
-        counter++;
-    }
-
-    if(unlikely(!counter)) {
-        debug(D_BACKEND, "BACKEND: %s.%s.%s: no values stored in database for range %lu to %lu",
-              host->hostname, st->id, rd->id,
-              (unsigned long)after, (unsigned long)before
-        );
-        return NAN;
-    }
-
-    if(unlikely((options & BACKEND_SOURCE_BITS) == BACKEND_SOURCE_DATA_SUM))
-        return sum;
-
-    return sum / (calculated_number)counter;
-}
-
-
-// discard a response received by a backend
-// after logging a simple of it to error.log
-
-static inline int discard_response(BUFFER *b, const char *backend) {
-    char sample[1024];
-    const char *s = buffer_tostring(b);
-    char *d = sample, *e = &sample[sizeof(sample) - 1];
-
-    for(; *s && d < e ;s++) {
-        char c = *s;
-        if(unlikely(!isprint(c))) c = ' ';
-        *d++ = c;
-    }
-    *d = '\0';
-
-    info("BACKEND: received %zu bytes from %s backend. Ignoring them. Sample: '%s'", buffer_strlen(b), backend, sample);
-    buffer_flush(b);
-    return 0;
-}
-
-
-// ----------------------------------------------------------------------------
-// graphite backend
-
-static inline int format_dimension_collected_graphite_plaintext(
-          BUFFER *b                 // the buffer to write data to
-        , const char *prefix        // the prefix to use
-        , RRDHOST *host             // the host this chart comes from
-        , const char *hostname      // the hostname (to override host->hostname)
-        , RRDSET *st                // the chart
-        , RRDDIM *rd                // the dimension
-        , time_t after              // the start timestamp
-        , time_t before             // the end timestamp
-        , uint32_t options          // BACKEND_SOURCE_* bitmap
-) {
-    (void)host;
-    (void)after;
-    (void)before;
-    (void)options;
-
-    char chart_name[RRD_ID_LENGTH_MAX + 1];
-    char dimension_name[RRD_ID_LENGTH_MAX + 1];
-    backend_name_copy(chart_name, (backend_send_names && st->name)?st->name:st->id, RRD_ID_LENGTH_MAX);
-    backend_name_copy(dimension_name, (backend_send_names && rd->name)?rd->name:rd->id, RRD_ID_LENGTH_MAX);
-
-    buffer_sprintf(
-            b
-            , "%s.%s.%s.%s " COLLECTED_NUMBER_FORMAT " %u\n"
-            , prefix
-            , hostname
-            , chart_name
-            , dimension_name
-            , rd->last_collected_value
-            , (uint32_t)rd->last_collected_time.tv_sec
-    );
-
-    return 1;
-}
-
-static inline int format_dimension_stored_graphite_plaintext(
-          BUFFER *b                 // the buffer to write data to
-        , const char *prefix        // the prefix to use
-        , RRDHOST *host             // the host this chart comes from
-        , const char *hostname      // the hostname (to override host->hostname)
-        , RRDSET *st                // the chart
-        , RRDDIM *rd                // the dimension
-        , time_t after              // the start timestamp
-        , time_t before             // the end timestamp
-        , uint32_t options          // BACKEND_SOURCE_* bitmap
-) {
-    (void)host;
-
-    char chart_name[RRD_ID_LENGTH_MAX + 1];
-    char dimension_name[RRD_ID_LENGTH_MAX + 1];
-    backend_name_copy(chart_name, (backend_send_names && st->name)?st->name:st->id, RRD_ID_LENGTH_MAX);
-    backend_name_copy(dimension_name, (backend_send_names && rd->name)?rd->name:rd->id, RRD_ID_LENGTH_MAX);
-
-    time_t first_t = after, last_t = before;
-    calculated_number value = backend_calculate_value_from_stored_data(st, rd, after, before, options, &first_t, &last_t);
-
-    if(!isnan(value)) {
-
-        buffer_sprintf(
-                b
-                , "%s.%s.%s.%s " CALCULATED_NUMBER_FORMAT " %u\n"
-                , prefix
-                , hostname
-                , chart_name
-                , dimension_name
-                , value
-                , (uint32_t) last_t
-        );
-
-        return 1;
-    }
-    return 0;
-}
-
-static inline int process_graphite_response(BUFFER *b) {
-    return discard_response(b, "graphite");
-}
-
-
-// ----------------------------------------------------------------------------
-// opentsdb backend
-
-static inline int format_dimension_collected_opentsdb_telnet(
-          BUFFER *b                 // the buffer to write data to
-        , const char *prefix        // the prefix to use
-        , RRDHOST *host             // the host this chart comes from
-        , const char *hostname      // the hostname (to override host->hostname)
-        , RRDSET *st                // the chart
-        , RRDDIM *rd                // the dimension
-        , time_t after              // the start timestamp
-        , time_t before             // the end timestamp
-        , uint32_t options          // BACKEND_SOURCE_* bitmap
-) {
-    (void)host;
-    (void)after;
-    (void)before;
-    (void)options;
-
-    char chart_name[RRD_ID_LENGTH_MAX + 1];
-    char dimension_name[RRD_ID_LENGTH_MAX + 1];
-    backend_name_copy(chart_name, (backend_send_names && st->name)?st->name:st->id, RRD_ID_LENGTH_MAX);
-    backend_name_copy(dimension_name, (backend_send_names && rd->name)?rd->name:rd->id, RRD_ID_LENGTH_MAX);
-
-    buffer_sprintf(
-            b
-            , "put %s.%s.%s %u " COLLECTED_NUMBER_FORMAT " host=%s%s%s\n"
-            , prefix
-            , chart_name
-            , dimension_name
-            , (uint32_t)rd->last_collected_time.tv_sec
-            , rd->last_collected_value
-            , hostname
-            , (host->tags)?" ":""
-            , (host->tags)?host->tags:""
-    );
-
-    return 1;
-}
-
-static inline int format_dimension_stored_opentsdb_telnet(
-          BUFFER *b                 // the buffer to write data to
-        , const char *prefix        // the prefix to use
-        , RRDHOST *host             // the host this chart comes from
-        , const char *hostname      // the hostname (to override host->hostname)
-        , RRDSET *st                // the chart
-        , RRDDIM *rd                // the dimension
-        , time_t after              // the start timestamp
-        , time_t before             // the end timestamp
-        , uint32_t options          // BACKEND_SOURCE_* bitmap
-) {
-    (void)host;
-
-    time_t first_t = after, last_t = before;
-    calculated_number value = backend_calculate_value_from_stored_data(st, rd, after, before, options, &first_t, &last_t);
-
-    char chart_name[RRD_ID_LENGTH_MAX + 1];
-    char dimension_name[RRD_ID_LENGTH_MAX + 1];
-    backend_name_copy(chart_name, (backend_send_names && st->name)?st->name:st->id, RRD_ID_LENGTH_MAX);
-    backend_name_copy(dimension_name, (backend_send_names && rd->name)?rd->name:rd->id, RRD_ID_LENGTH_MAX);
-
-    if(!isnan(value)) {
-
-        buffer_sprintf(
-                b
-                , "put %s.%s.%s %u " CALCULATED_NUMBER_FORMAT " host=%s%s%s\n"
-                , prefix
-                , chart_name
-                , dimension_name
-                , (uint32_t) last_t
-                , value
-                , hostname
-                , (host->tags)?" ":""
-                , (host->tags)?host->tags:""
-        );
-
-        return 1;
-    }
-    return 0;
-}
-
-static inline int process_opentsdb_response(BUFFER *b) {
-    return discard_response(b, "opentsdb");
-}
-
-
-// ----------------------------------------------------------------------------
-// json backend
-
-static inline int format_dimension_collected_json_plaintext(
-          BUFFER *b                 // the buffer to write data to
-        , const char *prefix        // the prefix to use
-        , RRDHOST *host             // the host this chart comes from
-        , const char *hostname      // the hostname (to override host->hostname)
-        , RRDSET *st                // the chart
-        , RRDDIM *rd                // the dimension
-        , time_t after              // the start timestamp
-        , time_t before             // the end timestamp
-        , uint32_t options          // BACKEND_SOURCE_* bitmap
-) {
-    (void)host;
-    (void)after;
-    (void)before;
-    (void)options;
-
-    const char *tags_pre = "", *tags_post = "", *tags = host->tags;
-    if(!tags) tags = "";
-
-    if(*tags) {
-        if(*tags == '{' || *tags == '[' || *tags == '"') {
-            tags_pre = "\"host_tags\":";
-            tags_post = ",";
-        }
-        else {
-            tags_pre = "\"host_tags\":\"";
-            tags_post = "\",";
-        }
-    }
-
-    buffer_sprintf(b, "{"
-        "\"prefix\":\"%s\","
-        "\"hostname\":\"%s\","
-        "%s%s%s"
-
-        "\"chart_id\":\"%s\","
-        "\"chart_name\":\"%s\","
-        "\"chart_family\":\"%s\","
-        "\"chart_context\": \"%s\","
-        "\"chart_type\":\"%s\","
-        "\"units\": \"%s\","
-
-        "\"id\":\"%s\","
-        "\"name\":\"%s\","
-        "\"value\":" COLLECTED_NUMBER_FORMAT ","
-
-        "\"timestamp\": %u}\n",
-            prefix,
-            hostname,
-            tags_pre, tags, tags_post,
-
-            st->id,
-            st->name,
-            st->family,
-            st->context,
-            st->type,
-            st->units,
-
-            rd->id,
-            rd->name,
-            rd->last_collected_value,
-
-            (uint32_t)rd->last_collected_time.tv_sec
-    );
-
-    return 1;
-}
-
-static inline int format_dimension_stored_json_plaintext(
-          BUFFER *b                 // the buffer to write data to
-        , const char *prefix        // the prefix to use
-        , RRDHOST *host             // the host this chart comes from
-        , const char *hostname      // the hostname (to override host->hostname)
-        , RRDSET *st                // the chart
-        , RRDDIM *rd                // the dimension
-        , time_t after              // the start timestamp
-        , time_t before             // the end timestamp
-        , uint32_t options          // BACKEND_SOURCE_* bitmap
-) {
-    (void)host;
-
-    time_t first_t = after, last_t = before;
-    calculated_number value = backend_calculate_value_from_stored_data(st, rd, after, before, options, &first_t, &last_t);
-
-    if(!isnan(value)) {
-        const char *tags_pre = "", *tags_post = "", *tags = host->tags;
-        if(!tags) tags = "";
-
-        if(*tags) {
-            if(*tags == '{' || *tags == '[' || *tags == '"') {
-                tags_pre = "\"host_tags\":";
-                tags_post = ",";
-            }
-            else {
-                tags_pre = "\"host_tags\":\"";
-                tags_post = "\",";
-            }
-        }
-
-        buffer_sprintf(b, "{"
-            "\"prefix\":\"%s\","
-            "\"hostname\":\"%s\","
-            "%s%s%s"
-
-            "\"chart_id\":\"%s\","
-            "\"chart_name\":\"%s\","
-            "\"chart_family\":\"%s\","
-            "\"chart_context\": \"%s\","
-            "\"chart_type\":\"%s\","
-            "\"units\": \"%s\","
-
-            "\"id\":\"%s\","
-            "\"name\":\"%s\","
-            "\"value\":" CALCULATED_NUMBER_FORMAT ","
-
-            "\"timestamp\": %u}\n", 
-                prefix,
-                hostname,
-                tags_pre, tags, tags_post,
-
-                st->id,
-                st->name,
-                st->family,
-                st->context,
-                st->type,
-                st->units,
-
-                rd->id,
-                rd->name,
-                value, 
-                
-                (uint32_t) last_t
-        );
-        
-        return 1;
-    }
-    return 0;
-}
-
-static inline int process_json_response(BUFFER *b) {
-    return discard_response(b, "json");
-}
-
-
-// ----------------------------------------------------------------------------
-// the backend thread
-
-static SIMPLE_PATTERN *charts_pattern = NULL;
-static SIMPLE_PATTERN *hosts_pattern = NULL;
-
-inline int backends_can_send_rrdset(uint32_t options, RRDSET *st) {
-    RRDHOST *host = st->rrdhost;
-
-    if(unlikely(rrdset_flag_check(st, RRDSET_FLAG_BACKEND_IGNORE)))
-        return 0;
-
-    if(unlikely(!rrdset_flag_check(st, RRDSET_FLAG_BACKEND_SEND))) {
-        // we have not checked this chart
-        if(simple_pattern_matches(charts_pattern, st->id) || simple_pattern_matches(charts_pattern, st->name))
-            rrdset_flag_set(st, RRDSET_FLAG_BACKEND_SEND);
-        else {
-            rrdset_flag_set(st, RRDSET_FLAG_BACKEND_IGNORE);
-            debug(D_BACKEND, "BACKEND: not sending chart '%s' of host '%s', because it is disabled for backends.", st->id, host->hostname);
-            return 0;
-        }
-    }
-
-    if(unlikely(!rrdset_is_available_for_backends(st))) {
-        debug(D_BACKEND, "BACKEND: not sending chart '%s' of host '%s', because it is not available for backends.", st->id, host->hostname);
-        return 0;
-    }
-
-    if(unlikely(st->rrd_memory_mode == RRD_MEMORY_MODE_NONE && !((options & BACKEND_SOURCE_BITS) == BACKEND_SOURCE_DATA_AS_COLLECTED))) {
-        debug(D_BACKEND, "BACKEND: not sending chart '%s' of host '%s' because its memory mode is '%s' and the backend requires database access.", st->id, host->hostname, rrd_memory_mode_name(host->rrd_memory_mode));
-        return 0;
-    }
-
-    return 1;
-}
-
-inline uint32_t backend_parse_data_source(const char *source, uint32_t mode) {
-    if(!strcmp(source, "raw") || !strcmp(source, "as collected") || !strcmp(source, "as-collected") || !strcmp(source, "as_collected") || !strcmp(source, "ascollected")) {
-        mode |= BACKEND_SOURCE_DATA_AS_COLLECTED;
-        mode &= ~(BACKEND_SOURCE_BITS ^ BACKEND_SOURCE_DATA_AS_COLLECTED);
-    }
-    else if(!strcmp(source, "average")) {
-        mode |= BACKEND_SOURCE_DATA_AVERAGE;
-        mode &= ~(BACKEND_SOURCE_BITS ^ BACKEND_SOURCE_DATA_AVERAGE);
-    }
-    else if(!strcmp(source, "sum") || !strcmp(source, "volume")) {
-        mode |= BACKEND_SOURCE_DATA_SUM;
-        mode &= ~(BACKEND_SOURCE_BITS ^ BACKEND_SOURCE_DATA_SUM);
-    }
-    else {
-        error("BACKEND: invalid data source method '%s'.", source);
-    }
-
-    return mode;
-}
-
-static void backends_main_cleanup(void *ptr) {
-    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)ptr;
-    static_thread->enabled = NETDATA_MAIN_THREAD_EXITING;
-
-    info("cleaning up...");
-
-    static_thread->enabled = NETDATA_MAIN_THREAD_EXITED;
-}
-
-void *backends_main(void *ptr) {
-    netdata_thread_cleanup_push(backends_main_cleanup, ptr);
-
-    int default_port = 0;
-    int sock = -1;
-    BUFFER *b = buffer_create(1), *response = buffer_create(1);
-    int (*backend_request_formatter)(BUFFER *, const char *, RRDHOST *, const char *, RRDSET *, RRDDIM *, time_t, time_t, uint32_t) = NULL;
-    int (*backend_response_checker)(BUFFER *) = NULL;
-
-    // ------------------------------------------------------------------------
-    // collect configuration options
-
-    struct timeval timeout = {
-            .tv_sec = 0,
-            .tv_usec = 0
-    };
-    int enabled             = config_get_boolean(CONFIG_SECTION_BACKEND, "enabled", 0);
-    const char *source      = config_get(CONFIG_SECTION_BACKEND, "data source", "average");
-    const char *type        = config_get(CONFIG_SECTION_BACKEND, "type", "graphite");
-    const char *destination = config_get(CONFIG_SECTION_BACKEND, "destination", "localhost");
-    backend_prefix          = config_get(CONFIG_SECTION_BACKEND, "prefix", "netdata");
-    const char *hostname    = config_get(CONFIG_SECTION_BACKEND, "hostname", localhost->hostname);
-    backend_update_every    = (int)config_get_number(CONFIG_SECTION_BACKEND, "update every", backend_update_every);
-    int buffer_on_failures  = (int)config_get_number(CONFIG_SECTION_BACKEND, "buffer on failures", 10);
-    long timeoutms          = config_get_number(CONFIG_SECTION_BACKEND, "timeout ms", backend_update_every * 2 * 1000);
-    backend_send_names      = config_get_boolean(CONFIG_SECTION_BACKEND, "send names instead of ids", backend_send_names);
-
-    charts_pattern = simple_pattern_create(config_get(CONFIG_SECTION_BACKEND, "send charts matching", "*"), NULL, SIMPLE_PATTERN_EXACT);
-    hosts_pattern = simple_pattern_create(config_get(CONFIG_SECTION_BACKEND, "send hosts matching", "localhost *"), NULL, SIMPLE_PATTERN_EXACT);
-
-
-    // ------------------------------------------------------------------------
-    // validate configuration options
-    // and prepare for sending data to our backend
-
-    backend_options = backend_parse_data_source(source, backend_options);
-
-    if(timeoutms < 1) {
-        error("BACKEND: invalid timeout %ld ms given. Assuming %d ms.", timeoutms, backend_update_every * 2 * 1000);
-        timeoutms = backend_update_every * 2 * 1000;
-    }
-    timeout.tv_sec  = (timeoutms * 1000) / 1000000;
-    timeout.tv_usec = (timeoutms * 1000) % 1000000;
-
-    if(!enabled || backend_update_every < 1)
-        goto cleanup;
-
-    // ------------------------------------------------------------------------
-    // select the backend type
-
-    if(!strcmp(type, "graphite") || !strcmp(type, "graphite:plaintext")) {
-
-        default_port = 2003;
-        backend_response_checker = process_graphite_response;
-
-        if((backend_options & BACKEND_SOURCE_BITS) == BACKEND_SOURCE_DATA_AS_COLLECTED)
-            backend_request_formatter = format_dimension_collected_graphite_plaintext;
-        else
-            backend_request_formatter = format_dimension_stored_graphite_plaintext;
-
-    }
-    else if(!strcmp(type, "opentsdb") || !strcmp(type, "opentsdb:telnet")) {
-
-        default_port = 4242;
-        backend_response_checker = process_opentsdb_response;
-
-        if((backend_options & BACKEND_SOURCE_BITS) == BACKEND_SOURCE_DATA_AS_COLLECTED)
-            backend_request_formatter = format_dimension_collected_opentsdb_telnet;
-        else
-            backend_request_formatter = format_dimension_stored_opentsdb_telnet;
-
-    }
-    else if (!strcmp(type, "json") || !strcmp(type, "json:plaintext")) {
-
-        default_port = 5448;
-        backend_response_checker = process_json_response;
-
-        if ((backend_options & BACKEND_SOURCE_BITS) == BACKEND_SOURCE_DATA_AS_COLLECTED)
-            backend_request_formatter = format_dimension_collected_json_plaintext;
-        else
-            backend_request_formatter = format_dimension_stored_json_plaintext;
-
-    }
-    else {
-        error("BACKEND: Unknown backend type '%s'", type);
-        goto cleanup;
-    }
-
-    if(backend_request_formatter == NULL || backend_response_checker == NULL) {
-        error("BACKEND: backend is misconfigured - disabling it.");
-        goto cleanup;
-    }
-
-
-    // ------------------------------------------------------------------------
-    // prepare the charts for monitoring the backend operation
-
-    struct rusage thread;
-
-    collected_number
-            chart_buffered_metrics = 0,
-            chart_lost_metrics = 0,
-            chart_sent_metrics = 0,
-            chart_buffered_bytes = 0,
-            chart_received_bytes = 0,
-            chart_sent_bytes = 0,
-            chart_receptions = 0,
-            chart_transmission_successes = 0,
-            chart_transmission_failures = 0,
-            chart_data_lost_events = 0,
-            chart_lost_bytes = 0,
-            chart_backend_reconnects = 0,
-            chart_backend_latency = 0;
-
-    RRDSET *chart_metrics = rrdset_create_localhost("netdata", "backend_metrics", NULL, "backend", NULL, "Netdata Buffered Metrics", "metrics", "backends", NULL, 130600, backend_update_every, RRDSET_TYPE_LINE);
-    rrddim_add(chart_metrics, "buffered", NULL,  1, 1, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_metrics, "lost",     NULL,  1, 1, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_metrics, "sent",     NULL,  1, 1, RRD_ALGORITHM_ABSOLUTE);
-
-    RRDSET *chart_bytes = rrdset_create_localhost("netdata", "backend_bytes", NULL, "backend", NULL, "Netdata Backend Data Size", "KB", "backends", NULL, 130610, backend_update_every, RRDSET_TYPE_AREA);
-    rrddim_add(chart_bytes, "buffered", NULL, 1, 1024, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_bytes, "lost",     NULL, 1, 1024, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_bytes, "sent",     NULL, 1, 1024, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_bytes, "received", NULL, 1, 1024, RRD_ALGORITHM_ABSOLUTE);
-
-    RRDSET *chart_ops = rrdset_create_localhost("netdata", "backend_ops", NULL, "backend", NULL, "Netdata Backend Operations", "operations", "backends", NULL, 130630, backend_update_every, RRDSET_TYPE_LINE);
-    rrddim_add(chart_ops, "write",     NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_ops, "discard",   NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_ops, "reconnect", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_ops, "failure",   NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
-    rrddim_add(chart_ops, "read",      NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
-
-    /*
-     * this is misleading - we can only measure the time we need to send data
-     * this time is not related to the time required for the data to travel to
-     * the backend database and the time that server needed to process them
-     *
-     * issue #1432 and https://www.softlab.ntua.gr/facilities/documentation/unix/unix-socket-faq/unix-socket-faq-2.html
-     *
-    RRDSET *chart_latency = rrdset_create_localhost("netdata", "backend_latency", NULL, "backend", NULL, "Netdata Backend Latency", "ms", "backends", NULL, 130620, backend_update_every, RRDSET_TYPE_AREA);
-    rrddim_add(chart_latency, "latency",   NULL,  1, 1000, RRD_ALGORITHM_ABSOLUTE);
-    */
-
-    RRDSET *chart_rusage = rrdset_create_localhost("netdata", "backend_thread_cpu", NULL, "backend", NULL, "NetData Backend Thread CPU usage", "milliseconds/s", "backends", NULL, 130630, backend_update_every, RRDSET_TYPE_STACKED);
-    rrddim_add(chart_rusage, "user",   NULL, 1, 1000, RRD_ALGORITHM_INCREMENTAL);
-    rrddim_add(chart_rusage, "system", NULL, 1, 1000, RRD_ALGORITHM_INCREMENTAL);
-
-
-    // ------------------------------------------------------------------------
-    // prepare the backend main loop
-
-    info("BACKEND: configured ('%s' on '%s' sending '%s' data, every %d seconds, as host '%s', with prefix '%s')", type, destination, source, backend_update_every, hostname, backend_prefix);
-
-    usec_t step_ut = backend_update_every * USEC_PER_SEC;
-    time_t after = now_realtime_sec();
-    int failures = 0;
-    heartbeat_t hb;
-    heartbeat_init(&hb);
-
-    while(!netdata_exit) {
-
-        // ------------------------------------------------------------------------
-        // Wait for the next iteration point.
-
-        heartbeat_next(&hb, step_ut);
-        time_t before = now_realtime_sec();
-        debug(D_BACKEND, "BACKEND: preparing buffer for timeframe %lu to %lu", (unsigned long)after, (unsigned long)before);
-
-        // ------------------------------------------------------------------------
-        // add to the buffer the data we need to send to the backend
-
-        netdata_thread_disable_cancelability();
-
-        size_t count_hosts = 0;
-        size_t count_charts_total = 0;
-        size_t count_dims_total = 0;
-
-        rrd_rdlock();
-        RRDHOST *host;
-        rrdhost_foreach_read(host) {
-            if(unlikely(!rrdhost_flag_check(host, RRDHOST_FLAG_BACKEND_SEND|RRDHOST_FLAG_BACKEND_DONT_SEND))) {
-                char *name = (host == localhost)?"localhost":host->hostname;
-                if (!hosts_pattern || simple_pattern_matches(hosts_pattern, name)) {
-                    rrdhost_flag_set(host, RRDHOST_FLAG_BACKEND_SEND);
-                    info("enabled backend for host '%s'", name);
-                }
-                else {
-                    rrdhost_flag_set(host, RRDHOST_FLAG_BACKEND_DONT_SEND);
-                    info("disabled backend for host '%s'", name);
-                }
-            }
-
-            if(unlikely(!rrdhost_flag_check(host, RRDHOST_FLAG_BACKEND_SEND)))
-                continue;
-
-            rrdhost_rdlock(host);
-
-            count_hosts++;
-            size_t count_charts = 0;
-            size_t count_dims = 0;
-            size_t count_dims_skipped = 0;
-
-            const char *__hostname = (host == localhost)?hostname:host->hostname;
-
-            RRDSET *st;
-            rrdset_foreach_read(st, host) {
-                if(likely(backends_can_send_rrdset(backend_options, st))) {
-                    rrdset_rdlock(st);
-
-                    count_charts++;
-
-                    RRDDIM *rd;
-                    rrddim_foreach_read(rd, st) {
-                        if (likely(rd->last_collected_time.tv_sec >= after)) {
-                            chart_buffered_metrics += backend_request_formatter(b, backend_prefix, host, __hostname, st, rd, after, before, backend_options);
-                            count_dims++;
-                        }
-                        else {
-                            debug(D_BACKEND, "BACKEND: not sending dimension '%s' of chart '%s' from host '%s', its last data collection (%lu) is not within our timeframe (%lu to %lu)", rd->id, st->id, __hostname, (unsigned long)rd->last_collected_time.tv_sec, (unsigned long)after, (unsigned long)before);
-                            count_dims_skipped++;
-                        }
-                    }
-
-                    rrdset_unlock(st);
-                }
-            }
-
-            debug(D_BACKEND, "BACKEND: sending host '%s', metrics of %zu dimensions, of %zu charts. Skipped %zu dimensions.", __hostname, count_dims, count_charts, count_dims_skipped);
-            count_charts_total += count_charts;
-            count_dims_total += count_dims;
-
-            rrdhost_unlock(host);
-        }
-        rrd_unlock();
-
-        netdata_thread_enable_cancelability();
-
-        debug(D_BACKEND, "BACKEND: buffer has %zu bytes, added metrics for %zu dimensions, of %zu charts, from %zu hosts", buffer_strlen(b), count_dims_total, count_charts_total, count_hosts);
-
-        // ------------------------------------------------------------------------
-
-        chart_buffered_bytes = (collected_number)buffer_strlen(b);
-
-        // reset the monitoring chart counters
-        chart_received_bytes =
-        chart_sent_bytes =
-        chart_sent_metrics =
-        chart_lost_metrics =
-        chart_transmission_successes =
-        chart_transmission_failures =
-        chart_data_lost_events =
-        chart_lost_bytes =
-        chart_backend_reconnects =
-        chart_backend_latency = 0;
-
-        if(unlikely(netdata_exit)) break;
-
-        //fprintf(stderr, "\nBACKEND BEGIN:\n%s\nBACKEND END\n", buffer_tostring(b)); // FIXME
-        //fprintf(stderr, "after = %lu, before = %lu\n", after, before);
-
-        // prepare for the next iteration
-        // to add incrementally data to buffer
-        after = before;
-
-        // ------------------------------------------------------------------------
-        // if we are connected, receive a response, without blocking
-
-        if(likely(sock != -1)) {
-            errno = 0;
-
-            // loop through to collect all data
-            while(sock != -1 && errno != EWOULDBLOCK) {
-                buffer_need_bytes(response, 4096);
-
-                ssize_t r = recv(sock, &response->buffer[response->len], response->size - response->len, MSG_DONTWAIT);
-                if(likely(r > 0)) {
-                    // we received some data
-                    response->len += r;
-                    chart_received_bytes += r;
-                    chart_receptions++;
-                }
-                else if(r == 0) {
-                    error("BACKEND: '%s' closed the socket", destination);
-                    close(sock);
-                    sock = -1;
-                }
-                else {
-                    // failed to receive data
-                    if(errno != EAGAIN && errno != EWOULDBLOCK) {
-                        error("BACKEND: cannot receive data from backend '%s'.", destination);
-                    }
-                }
-            }
-
-            // if we received data, process them
-            if(buffer_strlen(response))
-                backend_response_checker(response);
-        }
-
-        // ------------------------------------------------------------------------
-        // if we are not connected, connect to a backend server
-
-        if(unlikely(sock == -1)) {
-            usec_t start_ut = now_monotonic_usec();
-            size_t reconnects = 0;
-
-            sock = connect_to_one_of(destination, default_port, &timeout, &reconnects, NULL, 0);
-
-            chart_backend_reconnects += reconnects;
-            chart_backend_latency += now_monotonic_usec() - start_ut;
-        }
-
-        if(unlikely(netdata_exit)) break;
-
-        // ------------------------------------------------------------------------
-        // if we are connected, send our buffer to the backend server
-
-        if(likely(sock != -1)) {
-            size_t len = buffer_strlen(b);
-            usec_t start_ut = now_monotonic_usec();
-            int flags = 0;
-#ifdef MSG_NOSIGNAL
-            flags += MSG_NOSIGNAL;
-#endif
-
-            ssize_t written = send(sock, buffer_tostring(b), len, flags);
-            chart_backend_latency += now_monotonic_usec() - start_ut;
-            if(written != -1 && (size_t)written == len) {
-                // we sent the data successfully
-                chart_transmission_successes++;
-                chart_sent_bytes += written;
-                chart_sent_metrics = chart_buffered_metrics;
-
-                // reset the failures count
-                failures = 0;
-
-                // empty the buffer
-                buffer_flush(b);
-            }
-            else {
-                // oops! we couldn't send (all or some of the) data
-                error("BACKEND: failed to write data to database backend '%s'. Willing to write %zu bytes, wrote %zd bytes. Will re-connect.", destination, len, written);
-                chart_transmission_failures++;
-
-                if(written != -1)
-                    chart_sent_bytes += written;
-
-                // increment the counter we check for data loss
-                failures++;
-
-                // close the socket - we will re-open it next time
-                close(sock);
-                sock = -1;
-            }
-        }
-        else {
-            error("BACKEND: failed to update database backend '%s'", destination);
-            chart_transmission_failures++;
-
-            // increment the counter we check for data loss
-            failures++;
-        }
-
-        if(failures > buffer_on_failures) {
-            // too bad! we are going to lose data
-            chart_lost_bytes += buffer_strlen(b);
-            error("BACKEND: reached %d backend failures. Flushing buffers to protect this host - this results in data loss on back-end server '%s'", failures, destination);
-            buffer_flush(b);
-            failures = 0;
-            chart_data_lost_events++;
-            chart_lost_metrics = chart_buffered_metrics;
-        }
-
-        if(unlikely(netdata_exit)) break;
-
-        // ------------------------------------------------------------------------
-        // update the monitoring charts
-
-        if(likely(chart_ops->counter_done)) rrdset_next(chart_ops);
-        rrddim_set(chart_ops, "read",         chart_receptions);
-        rrddim_set(chart_ops, "write",        chart_transmission_successes);
-        rrddim_set(chart_ops, "discard",      chart_data_lost_events);
-        rrddim_set(chart_ops, "failure",      chart_transmission_failures);
-        rrddim_set(chart_ops, "reconnect",    chart_backend_reconnects);
-        rrdset_done(chart_ops);
-
-        if(likely(chart_metrics->counter_done)) rrdset_next(chart_metrics);
-        rrddim_set(chart_metrics, "buffered", chart_buffered_metrics);
-        rrddim_set(chart_metrics, "lost",     chart_lost_metrics);
-        rrddim_set(chart_metrics, "sent",     chart_sent_metrics);
-        rrdset_done(chart_metrics);
-
-        if(likely(chart_bytes->counter_done)) rrdset_next(chart_bytes);
-        rrddim_set(chart_bytes, "buffered",   chart_buffered_bytes);
-        rrddim_set(chart_bytes, "lost",       chart_lost_bytes);
-        rrddim_set(chart_bytes, "sent",       chart_sent_bytes);
-        rrddim_set(chart_bytes, "received",   chart_received_bytes);
-        rrdset_done(chart_bytes);
-
-        /*
-        if(likely(chart_latency->counter_done)) rrdset_next(chart_latency);
-        rrddim_set(chart_latency, "latency",  chart_backend_latency);
-        rrdset_done(chart_latency);
-        */
-
-        getrusage(RUSAGE_THREAD, &thread);
-        if(likely(chart_rusage->counter_done)) rrdset_next(chart_rusage);
-        rrddim_set(chart_rusage, "user",   thread.ru_utime.tv_sec * 1000000ULL + thread.ru_utime.tv_usec);
-        rrddim_set(chart_rusage, "system", thread.ru_stime.tv_sec * 1000000ULL + thread.ru_stime.tv_usec);
-        rrdset_done(chart_rusage);
-
-        if(likely(buffer_strlen(b) == 0))
-            chart_buffered_metrics = 0;
-
-        if(unlikely(netdata_exit)) break;
-    }
-
-cleanup:
-    if(sock != -1)
-        close(sock);
-
-    buffer_free(b);
-    buffer_free(response);
-
-    netdata_thread_cleanup_pop(1);
-    return NULL;
-}