Merging upstream version 1.11.0+dfsg.

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

1 files changed, 1279 insertions, 0 deletions

diff --git a/streaming/rrdpush.c b/streaming/rrdpush.c
new file mode 100644
index 000000000..df1a2177f
--- /dev/null
+++ b/streaming/rrdpush.c
@@ -0,0 +1,1279 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "rrdpush.h"
+
+/*
+ * rrdpush
+ *
+ * 3 threads are involved for all stream operations
+ *
+ * 1. a random data collection thread, calling rrdset_done_push()
+ *    this is called for each chart.
+ *
+ *    the output of this work is kept in a BUFFER in RRDHOST
+ *    the sender thread is signalled via a pipe (also in RRDHOST)
+ *
+ * 2. a sender thread running at the sending netdata
+ *    this is spawned automatically on the first chart to be pushed
+ *
+ *    It tries to push the metrics to the remote netdata, as fast
+ *    as possible (i.e. immediately after they are collected).
+ *
+ * 3. a receiver thread, running at the receiving netdata
+ *    this is spawned automatically when the sender connects to
+ *    the receiver.
+ *
+ */
+
+#define START_STREAMING_PROMPT "Hit me baby, push them over..."
+
+typedef enum {
+    RRDPUSH_MULTIPLE_CONNECTIONS_ALLOW,
+    RRDPUSH_MULTIPLE_CONNECTIONS_DENY_NEW
+} RRDPUSH_MULTIPLE_CONNECTIONS_STRATEGY;
+
+static struct config stream_config = {
+        .sections = NULL,
+        .mutex = NETDATA_MUTEX_INITIALIZER,
+        .index = {
+                .avl_tree = {
+                        .root = NULL,
+                        .compar = appconfig_section_compare
+                },
+                .rwlock = AVL_LOCK_INITIALIZER
+        }
+};
+
+unsigned int default_rrdpush_enabled = 0;
+char *default_rrdpush_destination = NULL;
+char *default_rrdpush_api_key = NULL;
+char *default_rrdpush_send_charts_matching = NULL;
+
+static void load_stream_conf() {
+    errno = 0;
+    char *filename = strdupz_path_subpath(netdata_configured_user_config_dir, "stream.conf");
+    if(!appconfig_load(&stream_config, filename, 0)) {
+        info("CONFIG: cannot load user config '%s'. Will try stock config.", filename);
+        freez(filename);
+
+        filename = strdupz_path_subpath(netdata_configured_stock_config_dir, "stream.conf");
+        if(!appconfig_load(&stream_config, filename, 0))
+            info("CONFIG: cannot load stock config '%s'. Running with internal defaults.", filename);
+    }
+    freez(filename);
+}
+
+int rrdpush_init() {
+    // --------------------------------------------------------------------
+    // load stream.conf
+    load_stream_conf();
+
+    default_rrdpush_enabled     = (unsigned int)appconfig_get_boolean(&stream_config, CONFIG_SECTION_STREAM, "enabled", default_rrdpush_enabled);
+    default_rrdpush_destination = appconfig_get(&stream_config, CONFIG_SECTION_STREAM, "destination", "");
+    default_rrdpush_api_key     = appconfig_get(&stream_config, CONFIG_SECTION_STREAM, "api key", "");
+    default_rrdpush_send_charts_matching      = appconfig_get(&stream_config, CONFIG_SECTION_STREAM, "send charts matching", "*");
+    rrdhost_free_orphan_time    = config_get_number(CONFIG_SECTION_GLOBAL, "cleanup orphan hosts after seconds", rrdhost_free_orphan_time);
+
+    if(default_rrdpush_enabled && (!default_rrdpush_destination || !*default_rrdpush_destination || !default_rrdpush_api_key || !*default_rrdpush_api_key)) {
+        error("STREAM [send]: cannot enable sending thread - information is missing.");
+        default_rrdpush_enabled = 0;
+    }
+
+    return default_rrdpush_enabled;
+}
+
+#define CONNECTED_TO_SIZE 100
+
+// data collection happens from multiple threads
+// each of these threads calls rrdset_done()
+// which in turn calls rrdset_done_push()
+// which uses this pipe to notify the streaming thread
+// that there are more data ready to be sent
+#define PIPE_READ 0
+#define PIPE_WRITE 1
+
+// to have the remote netdata re-sync the charts
+// to its current clock, we send for this many
+// iterations a BEGIN line without microseconds
+// this is for the first iterations of each chart
+unsigned int remote_clock_resync_iterations = 60;
+
+#define rrdpush_buffer_lock(host) netdata_mutex_lock(&((host)->rrdpush_sender_buffer_mutex))
+#define rrdpush_buffer_unlock(host) netdata_mutex_unlock(&((host)->rrdpush_sender_buffer_mutex))
+
+static inline int should_send_chart_matching(RRDSET *st) {
+    if(unlikely(!rrdset_flag_check(st, RRDSET_FLAG_ENABLED))) {
+        rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_SEND);
+        rrdset_flag_set(st, RRDSET_FLAG_UPSTREAM_IGNORE);
+    }
+    else if(!rrdset_flag_check(st, RRDSET_FLAG_UPSTREAM_SEND|RRDSET_FLAG_UPSTREAM_IGNORE)) {
+        RRDHOST *host = st->rrdhost;
+
+        if(simple_pattern_matches(host->rrdpush_send_charts_matching, st->id) ||
+            simple_pattern_matches(host->rrdpush_send_charts_matching, st->name)) {
+            rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_IGNORE);
+            rrdset_flag_set(st, RRDSET_FLAG_UPSTREAM_SEND);
+        }
+        else {
+            rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_SEND);
+            rrdset_flag_set(st, RRDSET_FLAG_UPSTREAM_IGNORE);
+        }
+    }
+
+    return(rrdset_flag_check(st, RRDSET_FLAG_UPSTREAM_SEND));
+}
+
+// checks if the current chart definition has been sent
+static inline int need_to_send_chart_definition(RRDSET *st) {
+    rrdset_check_rdlock(st);
+
+    if(unlikely(!(rrdset_flag_check(st, RRDSET_FLAG_UPSTREAM_EXPOSED))))
+        return 1;
+
+    RRDDIM *rd;
+    rrddim_foreach_read(rd, st) {
+        if(unlikely(!rd->exposed)) {
+            #ifdef NETDATA_INTERNAL_CHECKS
+            info("host '%s', chart '%s', dimension '%s' flag 'exposed' triggered chart refresh to upstream", st->rrdhost->hostname, st->id, rd->id);
+            #endif
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+// sends the current chart definition
+static inline void rrdpush_send_chart_definition_nolock(RRDSET *st) {
+    RRDHOST *host = st->rrdhost;
+
+    rrdset_flag_set(st, RRDSET_FLAG_UPSTREAM_EXPOSED);
+
+    // properly set the name for the remote end to parse it
+    char *name = "";
+    if(unlikely(strcmp(st->id, st->name))) {
+        // they differ
+        name = strchr(st->name, '.');
+        if(name)
+            name++;
+        else
+            name = "";
+    }
+
+    // info("CHART '%s' '%s'", st->id, name);
+
+    // send the chart
+    buffer_sprintf(
+            host->rrdpush_sender_buffer
+            , "CHART \"%s\" \"%s\" \"%s\" \"%s\" \"%s\" \"%s\" \"%s\" %ld %d \"%s %s %s %s\" \"%s\" \"%s\"\n"
+            , st->id
+            , name
+            , st->title
+            , st->units
+            , st->family
+            , st->context
+            , rrdset_type_name(st->chart_type)
+            , st->priority
+            , st->update_every
+            , rrdset_flag_check(st, RRDSET_FLAG_OBSOLETE)?"obsolete":""
+            , rrdset_flag_check(st, RRDSET_FLAG_DETAIL)?"detail":""
+            , rrdset_flag_check(st, RRDSET_FLAG_STORE_FIRST)?"store_first":""
+            , rrdset_flag_check(st, RRDSET_FLAG_HIDDEN)?"hidden":""
+            , (st->plugin_name)?st->plugin_name:""
+            , (st->module_name)?st->module_name:""
+    );
+
+    // send the dimensions
+    RRDDIM *rd;
+    rrddim_foreach_read(rd, st) {
+        buffer_sprintf(
+                host->rrdpush_sender_buffer
+                , "DIMENSION \"%s\" \"%s\" \"%s\" " COLLECTED_NUMBER_FORMAT " " COLLECTED_NUMBER_FORMAT " \"%s %s\"\n"
+                , rd->id
+                , rd->name
+                , rrd_algorithm_name(rd->algorithm)
+                , rd->multiplier
+                , rd->divisor
+                , rrddim_flag_check(rd, RRDDIM_FLAG_HIDDEN)?"hidden":""
+                , rrddim_flag_check(rd, RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS)?"noreset":""
+        );
+        rd->exposed = 1;
+    }
+
+    // send the chart local custom variables
+    RRDSETVAR *rs;
+    for(rs = st->variables; rs ;rs = rs->next) {
+        if(unlikely(rs->type == RRDVAR_TYPE_CALCULATED && rs->options & RRDVAR_OPTION_CUSTOM_CHART_VAR)) {
+            calculated_number *value = (calculated_number *) rs->value;
+
+            buffer_sprintf(
+                    host->rrdpush_sender_buffer
+                    , "VARIABLE CHART %s = " CALCULATED_NUMBER_FORMAT "\n"
+                    , rs->variable
+                    , *value
+            );
+        }
+    }
+
+    st->upstream_resync_time = st->last_collected_time.tv_sec + (remote_clock_resync_iterations * st->update_every);
+}
+
+// sends the current chart dimensions
+static inline void rrdpush_send_chart_metrics_nolock(RRDSET *st) {
+    RRDHOST *host = st->rrdhost;
+    buffer_sprintf(host->rrdpush_sender_buffer, "BEGIN \"%s\" %llu\n", st->id, (st->last_collected_time.tv_sec > st->upstream_resync_time)?st->usec_since_last_update:0);
+
+    RRDDIM *rd;
+    rrddim_foreach_read(rd, st) {
+        if(rd->updated && rd->exposed)
+            buffer_sprintf(host->rrdpush_sender_buffer
+                           , "SET \"%s\" = " COLLECTED_NUMBER_FORMAT "\n"
+                           , rd->id
+                           , rd->collected_value
+        );
+    }
+
+    buffer_strcat(host->rrdpush_sender_buffer, "END\n");
+}
+
+static void rrdpush_sender_thread_spawn(RRDHOST *host);
+
+void rrdset_push_chart_definition_now(RRDSET *st) {
+    RRDHOST *host = st->rrdhost;
+
+    if(unlikely(!host->rrdpush_send_enabled || !should_send_chart_matching(st)))
+        return;
+
+    rrdset_rdlock(st);
+    rrdpush_buffer_lock(host);
+    rrdpush_send_chart_definition_nolock(st);
+    rrdpush_buffer_unlock(host);
+    rrdset_unlock(st);
+}
+
+void rrdset_done_push(RRDSET *st) {
+    if(unlikely(!should_send_chart_matching(st)))
+        return;
+
+    RRDHOST *host = st->rrdhost;
+
+    rrdpush_buffer_lock(host);
+
+    if(unlikely(host->rrdpush_send_enabled && !host->rrdpush_sender_spawn))
+        rrdpush_sender_thread_spawn(host);
+
+    if(unlikely(!host->rrdpush_sender_buffer || !host->rrdpush_sender_connected)) {
+        if(unlikely(!host->rrdpush_sender_error_shown))
+            error("STREAM %s [send]: not ready - discarding collected metrics.", host->hostname);
+
+        host->rrdpush_sender_error_shown = 1;
+
+        rrdpush_buffer_unlock(host);
+        return;
+    }
+    else if(unlikely(host->rrdpush_sender_error_shown)) {
+        info("STREAM %s [send]: sending metrics...", host->hostname);
+        host->rrdpush_sender_error_shown = 0;
+    }
+
+    if(need_to_send_chart_definition(st))
+        rrdpush_send_chart_definition_nolock(st);
+
+    rrdpush_send_chart_metrics_nolock(st);
+
+    // signal the sender there are more data
+    if(host->rrdpush_sender_pipe[PIPE_WRITE] != -1 && write(host->rrdpush_sender_pipe[PIPE_WRITE], " ", 1) == -1)
+        error("STREAM %s [send]: cannot write to internal pipe", host->hostname);
+
+    rrdpush_buffer_unlock(host);
+}
+
+// ----------------------------------------------------------------------------
+// rrdpush sender thread
+
+static inline void rrdpush_sender_add_host_variable_to_buffer_nolock(RRDHOST *host, RRDVAR *rv) {
+    calculated_number *value = (calculated_number *)rv->value;
+
+    buffer_sprintf(
+            host->rrdpush_sender_buffer
+            , "VARIABLE HOST %s = " CALCULATED_NUMBER_FORMAT "\n"
+            , rv->name
+            , *value
+    );
+
+    debug(D_STREAM, "RRDVAR pushed HOST VARIABLE %s = " CALCULATED_NUMBER_FORMAT, rv->name, *value);
+}
+
+void rrdpush_sender_send_this_host_variable_now(RRDHOST *host, RRDVAR *rv) {
+    if(host->rrdpush_send_enabled && host->rrdpush_sender_spawn && host->rrdpush_sender_connected) {
+        rrdpush_buffer_lock(host);
+        rrdpush_sender_add_host_variable_to_buffer_nolock(host, rv);
+        rrdpush_buffer_unlock(host);
+    }
+}
+
+static int rrdpush_sender_thread_custom_host_variables_callback(void *rrdvar_ptr, void *host_ptr) {
+    RRDVAR *rv = (RRDVAR *)rrdvar_ptr;
+    RRDHOST *host = (RRDHOST *)host_ptr;
+
+    if(unlikely(rv->options & RRDVAR_OPTION_CUSTOM_HOST_VAR && rv->type == RRDVAR_TYPE_CALCULATED)) {
+        rrdpush_sender_add_host_variable_to_buffer_nolock(host, rv);
+
+        // return 1, so that the traversal will return the number of variables sent
+        return 1;
+    }
+
+    // returning a negative number will break the traversal
+    return 0;
+}
+
+static void rrdpush_sender_thread_send_custom_host_variables(RRDHOST *host) {
+    int ret = rrdvar_callback_for_all_host_variables(host, rrdpush_sender_thread_custom_host_variables_callback, host);
+    (void)ret;
+
+    debug(D_STREAM, "RRDVAR sent %d VARIABLES", ret);
+}
+
+// resets all the chart, so that their definitions
+// will be resent to the central netdata
+static void rrdpush_sender_thread_reset_all_charts(RRDHOST *host) {
+    rrdhost_rdlock(host);
+
+    RRDSET *st;
+    rrdset_foreach_read(st, host) {
+        rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_EXPOSED);
+
+        st->upstream_resync_time = 0;
+
+        rrdset_rdlock(st);
+
+        RRDDIM *rd;
+        rrddim_foreach_read(rd, st)
+            rd->exposed = 0;
+
+        rrdset_unlock(st);
+    }
+
+    rrdhost_unlock(host);
+}
+
+static inline void rrdpush_sender_thread_data_flush(RRDHOST *host) {
+    rrdpush_buffer_lock(host);
+
+    if(buffer_strlen(host->rrdpush_sender_buffer))
+        error("STREAM %s [send]: discarding %zu bytes of metrics already in the buffer.", host->hostname, buffer_strlen(host->rrdpush_sender_buffer));
+
+    buffer_flush(host->rrdpush_sender_buffer);
+
+    rrdpush_sender_thread_reset_all_charts(host);
+    rrdpush_sender_thread_send_custom_host_variables(host);
+
+    rrdpush_buffer_unlock(host);
+}
+
+void rrdpush_sender_thread_stop(RRDHOST *host) {
+    rrdpush_buffer_lock(host);
+    rrdhost_wrlock(host);
+
+    netdata_thread_t thr = 0;
+
+    if(host->rrdpush_sender_spawn) {
+        info("STREAM %s [send]: signaling sending thread to stop...", host->hostname);
+
+        // signal the thread that we want to join it
+        host->rrdpush_sender_join = 1;
+
+        // copy the thread id, so that we will be waiting for the right one
+        // even if a new one has been spawn
+        thr = host->rrdpush_sender_thread;
+
+        // signal it to cancel
+        netdata_thread_cancel(host->rrdpush_sender_thread);
+    }
+
+    rrdhost_unlock(host);
+    rrdpush_buffer_unlock(host);
+
+    if(thr != 0) {
+        info("STREAM %s [send]: waiting for the sending thread to stop...", host->hostname);
+        void *result;
+        netdata_thread_join(thr, &result);
+        info("STREAM %s [send]: sending thread has exited.", host->hostname);
+    }
+}
+
+static inline void rrdpush_sender_thread_close_socket(RRDHOST *host) {
+    host->rrdpush_sender_connected = 0;
+
+    if(host->rrdpush_sender_socket != -1) {
+        close(host->rrdpush_sender_socket);
+        host->rrdpush_sender_socket = -1;
+    }
+}
+
+static int rrdpush_sender_thread_connect_to_master(RRDHOST *host, int default_port, int timeout, size_t *reconnects_counter, char *connected_to, size_t connected_to_size) {
+    struct timeval tv = {
+            .tv_sec = timeout,
+            .tv_usec = 0
+    };
+
+    // make sure the socket is closed
+    rrdpush_sender_thread_close_socket(host);
+
+    debug(D_STREAM, "STREAM: Attempting to connect...");
+    info("STREAM %s [send to %s]: connecting...", host->hostname, host->rrdpush_send_destination);
+
+    host->rrdpush_sender_socket = connect_to_one_of(
+            host->rrdpush_send_destination
+            , default_port
+            , &tv
+            , reconnects_counter
+            , connected_to
+            , connected_to_size
+    );
+
+    if(unlikely(host->rrdpush_sender_socket == -1)) {
+        error("STREAM %s [send to %s]: failed to connect", host->hostname, host->rrdpush_send_destination);
+        return 0;
+    }
+
+    info("STREAM %s [send to %s]: initializing communication...", host->hostname, connected_to);
+
+    #define HTTP_HEADER_SIZE 8192
+    char http[HTTP_HEADER_SIZE + 1];
+    snprintfz(http, HTTP_HEADER_SIZE,
+            "STREAM key=%s&hostname=%s&registry_hostname=%s&machine_guid=%s&update_every=%d&os=%s&timezone=%s&tags=%s HTTP/1.1\r\n"
+                    "User-Agent: %s/%s\r\n"
+                    "Accept: */*\r\n\r\n"
+              , host->rrdpush_send_api_key
+              , host->hostname
+              , host->registry_hostname
+              , host->machine_guid
+              , default_rrd_update_every
+              , host->os
+              , host->timezone
+              , (host->tags)?host->tags:""
+              , host->program_name
+              , host->program_version
+    );
+
+    if(send_timeout(host->rrdpush_sender_socket, http, strlen(http), 0, timeout) == -1) {
+        error("STREAM %s [send to %s]: failed to send HTTP header to remote netdata.", host->hostname, connected_to);
+        rrdpush_sender_thread_close_socket(host);
+        return 0;
+    }
+
+    info("STREAM %s [send to %s]: waiting response from remote netdata...", host->hostname, connected_to);
+
+    if(recv_timeout(host->rrdpush_sender_socket, http, HTTP_HEADER_SIZE, 0, timeout) == -1) {
+        error("STREAM %s [send to %s]: remote netdata does not respond.", host->hostname, connected_to);
+        rrdpush_sender_thread_close_socket(host);
+        return 0;
+    }
+
+    if(strncmp(http, START_STREAMING_PROMPT, strlen(START_STREAMING_PROMPT)) != 0) {
+        error("STREAM %s [send to %s]: server is not replying properly (is it a netdata?).", host->hostname, connected_to);
+        rrdpush_sender_thread_close_socket(host);
+        return 0;
+    }
+
+    info("STREAM %s [send to %s]: established communication - ready to send metrics...", host->hostname, connected_to);
+
+    if(sock_setnonblock(host->rrdpush_sender_socket) < 0)
+        error("STREAM %s [send to %s]: cannot set non-blocking mode for socket.", host->hostname, connected_to);
+
+    if(sock_enlarge_out(host->rrdpush_sender_socket) < 0)
+        error("STREAM %s [send to %s]: cannot enlarge the socket buffer.", host->hostname, connected_to);
+
+    debug(D_STREAM, "STREAM: Connected on fd %d...", host->rrdpush_sender_socket);
+
+    return 1;
+}
+
+static void rrdpush_sender_thread_cleanup_callback(void *ptr) {
+    RRDHOST *host = (RRDHOST *)ptr;
+
+    rrdpush_buffer_lock(host);
+    rrdhost_wrlock(host);
+
+    info("STREAM %s [send]: sending thread cleans up...", host->hostname);
+
+    rrdpush_sender_thread_close_socket(host);
+
+    // close the pipe
+    if(host->rrdpush_sender_pipe[PIPE_READ] != -1) {
+        close(host->rrdpush_sender_pipe[PIPE_READ]);
+        host->rrdpush_sender_pipe[PIPE_READ] = -1;
+    }
+
+    if(host->rrdpush_sender_pipe[PIPE_WRITE] != -1) {
+        close(host->rrdpush_sender_pipe[PIPE_WRITE]);
+        host->rrdpush_sender_pipe[PIPE_WRITE] = -1;
+    }
+
+    buffer_free(host->rrdpush_sender_buffer);
+    host->rrdpush_sender_buffer = NULL;
+
+    if(!host->rrdpush_sender_join) {
+        info("STREAM %s [send]: sending thread detaches itself.", host->hostname);
+        netdata_thread_detach(netdata_thread_self());
+    }
+
+    host->rrdpush_sender_spawn = 0;
+
+    info("STREAM %s [send]: sending thread now exits.", host->hostname);
+
+    rrdhost_unlock(host);
+    rrdpush_buffer_unlock(host);
+}
+
+void *rrdpush_sender_thread(void *ptr) {
+    RRDHOST *host = (RRDHOST *)ptr;
+
+    if(!host->rrdpush_send_enabled || !host->rrdpush_send_destination || !*host->rrdpush_send_destination || !host->rrdpush_send_api_key || !*host->rrdpush_send_api_key) {
+        error("STREAM %s [send]: thread created (task id %d), but host has streaming disabled.", host->hostname, gettid());
+        return NULL;
+    }
+
+    info("STREAM %s [send]: thread created (task id %d)", host->hostname, gettid());
+
+    int timeout = (int)appconfig_get_number(&stream_config, CONFIG_SECTION_STREAM, "timeout seconds", 60);
+    int default_port = (int)appconfig_get_number(&stream_config, CONFIG_SECTION_STREAM, "default port", 19999);
+    size_t max_size = (size_t)appconfig_get_number(&stream_config, CONFIG_SECTION_STREAM, "buffer size bytes", 1024 * 1024);
+    unsigned int reconnect_delay = (unsigned int)appconfig_get_number(&stream_config, CONFIG_SECTION_STREAM, "reconnect delay seconds", 5);
+    remote_clock_resync_iterations = (unsigned int)appconfig_get_number(&stream_config, CONFIG_SECTION_STREAM, "initial clock resync iterations", remote_clock_resync_iterations);
+    char connected_to[CONNECTED_TO_SIZE + 1] = "";
+
+    // initialize rrdpush globals
+    host->rrdpush_sender_buffer = buffer_create(1);
+    host->rrdpush_sender_connected = 0;
+    if(pipe(host->rrdpush_sender_pipe) == -1) fatal("STREAM %s [send]: cannot create required pipe.", host->hostname);
+
+    // initialize local variables
+    size_t begin = 0;
+    size_t reconnects_counter = 0;
+    size_t sent_bytes = 0;
+    size_t sent_bytes_on_this_connection = 0;
+    size_t send_attempts = 0;
+
+
+    time_t last_sent_t = 0;
+    struct pollfd fds[2], *ifd, *ofd;
+    nfds_t fdmax;
+
+    ifd = &fds[0];
+    ofd = &fds[1];
+
+    size_t not_connected_loops = 0;
+
+    netdata_thread_cleanup_push(rrdpush_sender_thread_cleanup_callback, host);
+
+        for(; host->rrdpush_send_enabled && !netdata_exit ;) {
+            // check for outstanding cancellation requests
+            netdata_thread_testcancel();
+
+            // if we don't have socket open, lets wait a bit
+            if(unlikely(host->rrdpush_sender_socket == -1)) {
+                send_attempts = 0;
+
+                if(not_connected_loops == 0 && sent_bytes_on_this_connection > 0) {
+                    // fast re-connection on first disconnect
+                    sleep_usec(USEC_PER_MS * 500); // milliseconds
+                }
+                else {
+                    // slow re-connection on repeating errors
+                    sleep_usec(USEC_PER_SEC * reconnect_delay); // seconds
+                }
+
+                if(rrdpush_sender_thread_connect_to_master(host, default_port, timeout, &reconnects_counter, connected_to, CONNECTED_TO_SIZE)) {
+                    last_sent_t = now_monotonic_sec();
+
+                    // reset the buffer, to properly send charts and metrics
+                    rrdpush_sender_thread_data_flush(host);
+
+                    // send from the beginning
+                    begin = 0;
+
+                    // make sure the next reconnection will be immediate
+                    not_connected_loops = 0;
+
+                    // reset the bytes we have sent for this session
+                    sent_bytes_on_this_connection = 0;
+
+                    // let the data collection threads know we are ready
+                    host->rrdpush_sender_connected = 1;
+                }
+                else {
+                    // increase the failed connections counter
+                    not_connected_loops++;
+
+                    // reset the number of bytes sent
+                    sent_bytes_on_this_connection = 0;
+                }
+
+                // loop through
+                continue;
+            }
+            else if(unlikely(now_monotonic_sec() - last_sent_t > timeout)) {
+                error("STREAM %s [send to %s]: could not send metrics for %d seconds - closing connection - we have sent %zu bytes on this connection via %zu send attempts.", host->hostname, connected_to, timeout, sent_bytes_on_this_connection, send_attempts);
+                rrdpush_sender_thread_close_socket(host);
+            }
+
+            ifd->fd = host->rrdpush_sender_pipe[PIPE_READ];
+            ifd->events = POLLIN;
+            ifd->revents = 0;
+
+            ofd->fd = host->rrdpush_sender_socket;
+            ofd->revents = 0;
+            if(ofd->fd != -1 && begin < buffer_strlen(host->rrdpush_sender_buffer)) {
+                debug(D_STREAM, "STREAM: Requesting data output on streaming socket %d...", ofd->fd);
+                ofd->events = POLLOUT;
+                fdmax = 2;
+                send_attempts++;
+            }
+            else {
+                debug(D_STREAM, "STREAM: Not requesting data output on streaming socket %d (nothing to send now)...", ofd->fd);
+                ofd->events = 0;
+                fdmax = 1;
+            }
+
+            debug(D_STREAM, "STREAM: Waiting for poll() events (current buffer length %zu bytes)...", buffer_strlen(host->rrdpush_sender_buffer));
+            if(unlikely(netdata_exit)) break;
+            int retval = poll(fds, fdmax, 1000);
+            if(unlikely(netdata_exit)) break;
+
+            if(unlikely(retval == -1)) {
+                debug(D_STREAM, "STREAM: poll() failed (current buffer length %zu bytes)...", buffer_strlen(host->rrdpush_sender_buffer));
+
+                if(errno == EAGAIN || errno == EINTR) {
+                    debug(D_STREAM, "STREAM: poll() failed with EAGAIN or EINTR...");
+                }
+                else {
+                    error("STREAM %s [send to %s]: failed to poll(). Closing socket.", host->hostname, connected_to);
+                    rrdpush_sender_thread_close_socket(host);
+                }
+
+                continue;
+            }
+            else if(likely(retval)) {
+                if (ifd->revents & POLLIN || ifd->revents & POLLPRI) {
+                    debug(D_STREAM, "STREAM: Data added to send buffer (current buffer length %zu bytes)...", buffer_strlen(host->rrdpush_sender_buffer));
+
+                    char buffer[1000 + 1];
+                    if (read(host->rrdpush_sender_pipe[PIPE_READ], buffer, 1000) == -1)
+                        error("STREAM %s [send to %s]: cannot read from internal pipe.", host->hostname, connected_to);
+                }
+
+                if (ofd->revents & POLLOUT) {
+                    if (begin < buffer_strlen(host->rrdpush_sender_buffer)) {
+                        debug(D_STREAM, "STREAM: Sending data (current buffer length %zu bytes, begin = %zu)...", buffer_strlen(host->rrdpush_sender_buffer), begin);
+
+                        // BEGIN RRDPUSH LOCKED SESSION
+
+                        // during this session, data collectors
+                        // will not be able to append data to our buffer
+                        // but the socket is in non-blocking mode
+                        // so, we will not block at send()
+
+                        netdata_thread_disable_cancelability();
+
+                        debug(D_STREAM, "STREAM: Getting exclusive lock on host...");
+                        rrdpush_buffer_lock(host);
+
+                        debug(D_STREAM, "STREAM: Sending data, starting from %zu, size %zu...", begin, buffer_strlen(host->rrdpush_sender_buffer));
+                        ssize_t ret = send(host->rrdpush_sender_socket, &host->rrdpush_sender_buffer->buffer[begin], buffer_strlen(host->rrdpush_sender_buffer) - begin, MSG_DONTWAIT);
+                        if (unlikely(ret == -1)) {
+                            if (errno != EAGAIN && errno != EINTR && errno != EWOULDBLOCK) {
+                                debug(D_STREAM, "STREAM: Send failed - closing socket...");
+                                error("STREAM %s [send to %s]: failed to send metrics - closing connection - we have sent %zu bytes on this connection.", host->hostname, connected_to, sent_bytes_on_this_connection);
+                                rrdpush_sender_thread_close_socket(host);
+                            }
+                            else {
+                                debug(D_STREAM, "STREAM: Send failed - will retry...");
+                            }
+                        }
+                        else if (likely(ret > 0)) {
+                            // DEBUG - dump the string to see it
+                            //char c = host->rrdpush_sender_buffer->buffer[begin + ret];
+                            //host->rrdpush_sender_buffer->buffer[begin + ret] = '\0';
+                            //debug(D_STREAM, "STREAM: sent from %zu to %zd:\n%s\n", begin, ret, &host->rrdpush_sender_buffer->buffer[begin]);
+                            //host->rrdpush_sender_buffer->buffer[begin + ret] = c;
+
+                            sent_bytes_on_this_connection += ret;
+                            sent_bytes += ret;
+                            begin += ret;
+
+                            if (begin == buffer_strlen(host->rrdpush_sender_buffer)) {
+                                // we send it all
+
+                                debug(D_STREAM, "STREAM: Sent %zd bytes (the whole buffer)...", ret);
+                                buffer_flush(host->rrdpush_sender_buffer);
+                                begin = 0;
+                            }
+                            else {
+                                debug(D_STREAM, "STREAM: Sent %zd bytes (part of the data buffer)...", ret);
+                            }
+
+                            last_sent_t = now_monotonic_sec();
+                        }
+                        else {
+                            debug(D_STREAM, "STREAM: send() returned %zd - closing the socket...", ret);
+                            error("STREAM %s [send to %s]: failed to send metrics (send() returned %zd) - closing connection - we have sent %zu bytes on this connection.",
+                                  host->hostname, connected_to, ret, sent_bytes_on_this_connection);
+                            rrdpush_sender_thread_close_socket(host);
+                        }
+
+                        debug(D_STREAM, "STREAM: Releasing exclusive lock on host...");
+                        rrdpush_buffer_unlock(host);
+
+                        netdata_thread_enable_cancelability();
+
+                        // END RRDPUSH LOCKED SESSION
+                    }
+                    else {
+                        debug(D_STREAM, "STREAM: we have sent the entire buffer, but we received POLLOUT...");
+                    }
+                }
+
+                if(host->rrdpush_sender_socket != -1) {
+                    char *error = NULL;
+                    
+                    if (unlikely(ofd->revents & POLLERR))
+                        error = "socket reports errors (POLLERR)";
+                        
+                    else if (unlikely(ofd->revents & POLLHUP))
+                        error = "connection closed by remote end (POLLHUP)";
+                        
+                    else if (unlikely(ofd->revents & POLLNVAL))
+                        error = "connection is invalid (POLLNVAL)";
+                    
+                    if(unlikely(error)) {
+                        debug(D_STREAM, "STREAM: %s - closing socket...", error);
+                        error("STREAM %s [send to %s]: %s - reopening socket - we have sent %zu bytes on this connection.", host->hostname, connected_to, error, sent_bytes_on_this_connection);
+                        rrdpush_sender_thread_close_socket(host);
+                    }
+                }
+            }
+            else {
+                debug(D_STREAM, "STREAM: poll() timed out.");
+            }
+
+            // protection from overflow
+            if(buffer_strlen(host->rrdpush_sender_buffer) > max_size) {
+                debug(D_STREAM, "STREAM: Buffer is too big (%zu bytes), bigger than the max (%zu) - flushing it...", buffer_strlen(host->rrdpush_sender_buffer), max_size);
+                errno = 0;
+                error("STREAM %s [send to %s]: too many data pending - buffer is %zu bytes long, %zu unsent - we have sent %zu bytes in total, %zu on this connection. Closing connection to flush the data.", host->hostname, connected_to, host->rrdpush_sender_buffer->len, host->rrdpush_sender_buffer->len - begin, sent_bytes, sent_bytes_on_this_connection);
+                rrdpush_sender_thread_close_socket(host);
+            }
+        }
+
+    netdata_thread_cleanup_pop(1);
+    return NULL;
+}
+
+
+// ----------------------------------------------------------------------------
+// rrdpush receiver thread
+
+static void log_stream_connection(const char *client_ip, const char *client_port, const char *api_key, const char *machine_guid, const char *host, const char *msg) {
+    log_access("STREAM: %d '[%s]:%s' '%s' host '%s' api key '%s' machine guid '%s'", gettid(), client_ip, client_port, msg, host, api_key, machine_guid);
+}
+
+static RRDPUSH_MULTIPLE_CONNECTIONS_STRATEGY get_multiple_connections_strategy(struct config *c, const char *section, const char *name, RRDPUSH_MULTIPLE_CONNECTIONS_STRATEGY def) {
+    char *value;
+    switch(def) {
+        default:
+        case RRDPUSH_MULTIPLE_CONNECTIONS_ALLOW:
+            value = "allow";
+            break;
+
+        case RRDPUSH_MULTIPLE_CONNECTIONS_DENY_NEW:
+            value = "deny";
+            break;
+    }
+
+    value = appconfig_get(c, section, name, value);
+
+    RRDPUSH_MULTIPLE_CONNECTIONS_STRATEGY ret = def;
+
+    if(strcasecmp(value, "allow") == 0 || strcasecmp(value, "permit") == 0 || strcasecmp(value, "accept") == 0)
+        ret = RRDPUSH_MULTIPLE_CONNECTIONS_ALLOW;
+
+    else if(strcasecmp(value, "deny") == 0 || strcasecmp(value, "reject") == 0 || strcasecmp(value, "block") == 0)
+        ret = RRDPUSH_MULTIPLE_CONNECTIONS_DENY_NEW;
+
+    else
+        error("Invalid stream config value at section [%s], setting '%s', value '%s'", section, name, value);
+
+    return ret;
+}
+
+static int rrdpush_receive(int fd
+                           , const char *key
+                           , const char *hostname
+                           , const char *registry_hostname
+                           , const char *machine_guid
+                           , const char *os
+                           , const char *timezone
+                           , const char *tags
+                           , const char *program_name
+                           , const char *program_version
+                           , int update_every
+                           , char *client_ip
+                           , char *client_port
+) {
+    RRDHOST *host;
+    int history = default_rrd_history_entries;
+    RRD_MEMORY_MODE mode = default_rrd_memory_mode;
+    int health_enabled = default_health_enabled;
+    int rrdpush_enabled = default_rrdpush_enabled;
+    char *rrdpush_destination = default_rrdpush_destination;
+    char *rrdpush_api_key = default_rrdpush_api_key;
+    char *rrdpush_send_charts_matching = default_rrdpush_send_charts_matching;
+    time_t alarms_delay = 60;
+    RRDPUSH_MULTIPLE_CONNECTIONS_STRATEGY rrdpush_multiple_connections_strategy = RRDPUSH_MULTIPLE_CONNECTIONS_ALLOW;
+
+    update_every = (int)appconfig_get_number(&stream_config, machine_guid, "update every", update_every);
+    if(update_every < 0) update_every = 1;
+
+    history = (int)appconfig_get_number(&stream_config, key, "default history", history);
+    history = (int)appconfig_get_number(&stream_config, machine_guid, "history", history);
+    if(history < 5) history = 5;
+
+    mode = rrd_memory_mode_id(appconfig_get(&stream_config, key, "default memory mode", rrd_memory_mode_name(mode)));
+    mode = rrd_memory_mode_id(appconfig_get(&stream_config, machine_guid, "memory mode", rrd_memory_mode_name(mode)));
+
+    health_enabled = appconfig_get_boolean_ondemand(&stream_config, key, "health enabled by default", health_enabled);
+    health_enabled = appconfig_get_boolean_ondemand(&stream_config, machine_guid, "health enabled", health_enabled);
+
+    alarms_delay = appconfig_get_number(&stream_config, key, "default postpone alarms on connect seconds", alarms_delay);
+    alarms_delay = appconfig_get_number(&stream_config, machine_guid, "postpone alarms on connect seconds", alarms_delay);
+
+    rrdpush_enabled = appconfig_get_boolean(&stream_config, key, "default proxy enabled", rrdpush_enabled);
+    rrdpush_enabled = appconfig_get_boolean(&stream_config, machine_guid, "proxy enabled", rrdpush_enabled);
+
+    rrdpush_destination = appconfig_get(&stream_config, key, "default proxy destination", rrdpush_destination);
+    rrdpush_destination = appconfig_get(&stream_config, machine_guid, "proxy destination", rrdpush_destination);
+
+    rrdpush_api_key = appconfig_get(&stream_config, key, "default proxy api key", rrdpush_api_key);
+    rrdpush_api_key = appconfig_get(&stream_config, machine_guid, "proxy api key", rrdpush_api_key);
+
+    rrdpush_multiple_connections_strategy = get_multiple_connections_strategy(&stream_config, key, "multiple connections", rrdpush_multiple_connections_strategy);
+    rrdpush_multiple_connections_strategy = get_multiple_connections_strategy(&stream_config, machine_guid, "multiple connections", rrdpush_multiple_connections_strategy);
+
+    rrdpush_send_charts_matching = appconfig_get(&stream_config, key, "default proxy send charts matching", rrdpush_send_charts_matching);
+    rrdpush_send_charts_matching = appconfig_get(&stream_config, machine_guid, "proxy send charts matching", rrdpush_send_charts_matching);
+
+    tags = appconfig_set_default(&stream_config, machine_guid, "host tags", (tags)?tags:"");
+    if(tags && !*tags) tags = NULL;
+
+    if(!strcmp(machine_guid, "localhost"))
+        host = localhost;
+    else
+        host = rrdhost_find_or_create(
+                hostname
+                , registry_hostname
+                , machine_guid
+                , os
+                , timezone
+                , tags
+                , program_name
+                , program_version
+                , update_every
+                , history
+                , mode
+                , (unsigned int)(health_enabled != CONFIG_BOOLEAN_NO)
+                , (unsigned int)(rrdpush_enabled && rrdpush_destination && *rrdpush_destination && rrdpush_api_key && *rrdpush_api_key)
+                , rrdpush_destination
+                , rrdpush_api_key
+                , rrdpush_send_charts_matching
+        );
+
+    if(!host) {
+        close(fd);
+        log_stream_connection(client_ip, client_port, key, machine_guid, hostname, "FAILED - CANNOT ACQUIRE HOST");
+        error("STREAM %s [receive from [%s]:%s]: failed to find/create host structure.", hostname, client_ip, client_port);
+        return 1;
+    }
+
+#ifdef NETDATA_INTERNAL_CHECKS
+    info("STREAM %s [receive from [%s]:%s]: client willing to stream metrics for host '%s' with machine_guid '%s': update every = %d, history = %ld, memory mode = %s, health %s, tags '%s'"
+         , hostname
+         , client_ip
+         , client_port
+         , host->hostname
+         , host->machine_guid
+         , host->rrd_update_every
+         , host->rrd_history_entries
+         , rrd_memory_mode_name(host->rrd_memory_mode)
+         , (health_enabled == CONFIG_BOOLEAN_NO)?"disabled":((health_enabled == CONFIG_BOOLEAN_YES)?"enabled":"auto")
+         , host->tags?host->tags:""
+    );
+#endif // NETDATA_INTERNAL_CHECKS
+
+    struct plugind cd = {
+            .enabled = 1,
+            .update_every = default_rrd_update_every,
+            .pid = 0,
+            .serial_failures = 0,
+            .successful_collections = 0,
+            .obsolete = 0,
+            .started_t = now_realtime_sec(),
+            .next = NULL,
+    };
+
+    // put the client IP and port into the buffers used by plugins.d
+    snprintfz(cd.id,           CONFIG_MAX_NAME,  "%s:%s", client_ip, client_port);
+    snprintfz(cd.filename,     FILENAME_MAX,     "%s:%s", client_ip, client_port);
+    snprintfz(cd.fullfilename, FILENAME_MAX,     "%s:%s", client_ip, client_port);
+    snprintfz(cd.cmd,          PLUGINSD_CMD_MAX, "%s:%s", client_ip, client_port);
+
+    info("STREAM %s [receive from [%s]:%s]: initializing communication...", host->hostname, client_ip, client_port);
+    if(send_timeout(fd, START_STREAMING_PROMPT, strlen(START_STREAMING_PROMPT), 0, 60) != strlen(START_STREAMING_PROMPT)) {
+        log_stream_connection(client_ip, client_port, key, host->machine_guid, host->hostname, "FAILED - CANNOT REPLY");
+        error("STREAM %s [receive from [%s]:%s]: cannot send ready command.", host->hostname, client_ip, client_port);
+        close(fd);
+        return 0;
+    }
+
+    // remove the non-blocking flag from the socket
+    if(sock_delnonblock(fd) < 0)
+        error("STREAM %s [receive from [%s]:%s]: cannot remove the non-blocking flag from socket %d", host->hostname, client_ip, client_port, fd);
+
+    // convert the socket to a FILE *
+    FILE *fp = fdopen(fd, "r");
+    if(!fp) {
+        log_stream_connection(client_ip, client_port, key, host->machine_guid, host->hostname, "FAILED - SOCKET ERROR");
+        error("STREAM %s [receive from [%s]:%s]: failed to get a FILE for FD %d.", host->hostname, client_ip, client_port, fd);
+        close(fd);
+        return 0;
+    }
+
+    rrdhost_wrlock(host);
+    if(host->connected_senders > 0) {
+        switch(rrdpush_multiple_connections_strategy) {
+            case RRDPUSH_MULTIPLE_CONNECTIONS_ALLOW:
+                info("STREAM %s [receive from [%s]:%s]: multiple streaming connections for the same host detected. If multiple netdata are pushing metrics for the same charts, at the same time, the result is unexpected.", host->hostname, client_ip, client_port);
+                break;
+
+            case RRDPUSH_MULTIPLE_CONNECTIONS_DENY_NEW:
+                rrdhost_unlock(host);
+                log_stream_connection(client_ip, client_port, key, host->machine_guid, host->hostname, "REJECTED - ALREADY CONNECTED");
+                info("STREAM %s [receive from [%s]:%s]: multiple streaming connections for the same host detected. Rejecting new connection.", host->hostname, client_ip, client_port);
+                fclose(fp);
+                return 0;
+        }
+    }
+
+    rrdhost_flag_clear(host, RRDHOST_FLAG_ORPHAN);
+    host->connected_senders++;
+    host->senders_disconnected_time = 0;
+    if(health_enabled != CONFIG_BOOLEAN_NO) {
+        if(alarms_delay > 0) {
+            host->health_delay_up_to = now_realtime_sec() + alarms_delay;
+            info("Postponing health checks for %ld seconds, on host '%s', because it was just connected."
+            , alarms_delay
+            , host->hostname
+            );
+        }
+    }
+    rrdhost_unlock(host);
+
+    // call the plugins.d processor to receive the metrics
+    info("STREAM %s [receive from [%s]:%s]: receiving metrics...", host->hostname, client_ip, client_port);
+    log_stream_connection(client_ip, client_port, key, host->machine_guid, host->hostname, "CONNECTED");
+
+    size_t count = pluginsd_process(host, &cd, fp, 1);
+
+    log_stream_connection(client_ip, client_port, key, host->machine_guid, host->hostname, "DISCONNECTED");
+    error("STREAM %s [receive from [%s]:%s]: disconnected (completed %zu updates).", host->hostname, client_ip, client_port, count);
+
+    rrdhost_wrlock(host);
+    host->senders_disconnected_time = now_realtime_sec();
+    host->connected_senders--;
+    if(!host->connected_senders) {
+        rrdhost_flag_set(host, RRDHOST_FLAG_ORPHAN);
+        if(health_enabled == CONFIG_BOOLEAN_AUTO)
+            host->health_enabled = 0;
+    }
+    rrdhost_unlock(host);
+
+    if(host->connected_senders == 0)
+        rrdpush_sender_thread_stop(host);
+
+    // cleanup
+    fclose(fp);
+
+    return (int)count;
+}
+
+struct rrdpush_thread {
+    int fd;
+    char *key;
+    char *hostname;
+    char *registry_hostname;
+    char *machine_guid;
+    char *os;
+    char *timezone;
+    char *tags;
+    char *client_ip;
+    char *client_port;
+    char *program_name;
+    char *program_version;
+    int update_every;
+};
+
+static void rrdpush_receiver_thread_cleanup(void *ptr) {
+    static __thread int executed = 0;
+    if(!executed) {
+        executed = 1;
+        struct rrdpush_thread *rpt = (struct rrdpush_thread *) ptr;
+
+        info("STREAM %s [receive from [%s]:%s]: receive thread ended (task id %d)", rpt->hostname, rpt->client_ip, rpt->client_port, gettid());
+
+        freez(rpt->key);
+        freez(rpt->hostname);
+        freez(rpt->registry_hostname);
+        freez(rpt->machine_guid);
+        freez(rpt->os);
+        freez(rpt->timezone);
+        freez(rpt->tags);
+        freez(rpt->client_ip);
+        freez(rpt->client_port);
+        freez(rpt->program_name);
+        freez(rpt->program_version);
+        freez(rpt);
+    }
+}
+
+static void *rrdpush_receiver_thread(void *ptr) {
+    netdata_thread_cleanup_push(rrdpush_receiver_thread_cleanup, ptr);
+
+        struct rrdpush_thread *rpt = (struct rrdpush_thread *)ptr;
+        info("STREAM %s [%s]:%s: receive thread created (task id %d)", rpt->hostname, rpt->client_ip, rpt->client_port, gettid());
+
+        rrdpush_receive(
+                rpt->fd
+                , rpt->key
+                , rpt->hostname
+                , rpt->registry_hostname
+                , rpt->machine_guid
+                , rpt->os
+                , rpt->timezone
+                , rpt->tags
+                , rpt->program_name
+                , rpt->program_version
+                , rpt->update_every
+                , rpt->client_ip
+                , rpt->client_port
+        );
+
+    netdata_thread_cleanup_pop(1);
+    return NULL;
+}
+
+static void rrdpush_sender_thread_spawn(RRDHOST *host) {
+    rrdhost_wrlock(host);
+
+    if(!host->rrdpush_sender_spawn) {
+        char tag[NETDATA_THREAD_TAG_MAX + 1];
+        snprintfz(tag, NETDATA_THREAD_TAG_MAX, "STREAM_SENDER[%s]", host->hostname);
+
+        if(netdata_thread_create(&host->rrdpush_sender_thread, tag, NETDATA_THREAD_OPTION_JOINABLE, rrdpush_sender_thread, (void *) host))
+            error("STREAM %s [send]: failed to create new thread for client.", host->hostname);
+        else
+            host->rrdpush_sender_spawn = 1;
+    }
+
+    rrdhost_unlock(host);
+}
+
+int rrdpush_receiver_permission_denied(struct web_client *w) {
+    // we always respond with the same message and error code
+    // to prevent an attacker from gaining info about the error
+    buffer_flush(w->response.data);
+    buffer_sprintf(w->response.data, "You are not permitted to access this. Check the logs for more info.");
+    return 401;
+}
+
+int rrdpush_receiver_too_busy_now(struct web_client *w) {
+    // we always respond with the same message and error code
+    // to prevent an attacker from gaining info about the error
+    buffer_flush(w->response.data);
+    buffer_sprintf(w->response.data, "The server is too busy now to accept this request. Try later.");
+    return 503;
+}
+
+int rrdpush_receiver_thread_spawn(RRDHOST *host, struct web_client *w, char *url) {
+    (void)host;
+
+    info("clients wants to STREAM metrics.");
+
+    char *key = NULL, *hostname = NULL, *registry_hostname = NULL, *machine_guid = NULL, *os = "unknown", *timezone = "unknown", *tags = NULL;
+    int update_every = default_rrd_update_every;
+    char buf[GUID_LEN + 1];
+
+    while(url) {
+        char *value = mystrsep(&url, "?&");
+        if(!value || !*value) continue;
+
+        char *name = mystrsep(&value, "=");
+        if(!name || !*name) continue;
+        if(!value || !*value) continue;
+
+        if(!strcmp(name, "key"))
+            key = value;
+        else if(!strcmp(name, "hostname"))
+            hostname = value;
+        else if(!strcmp(name, "registry_hostname"))
+            registry_hostname = value;
+        else if(!strcmp(name, "machine_guid"))
+            machine_guid = value;
+        else if(!strcmp(name, "update_every"))
+            update_every = (int)strtoul(value, NULL, 0);
+        else if(!strcmp(name, "os"))
+            os = value;
+        else if(!strcmp(name, "timezone"))
+            timezone = value;
+        else if(!strcmp(name, "tags"))
+            tags = value;
+        else
+            info("STREAM [receive from [%s]:%s]: request has parameter '%s' = '%s', which is not used.", w->client_ip, w->client_port, key, value);
+    }
+
+    if(!key || !*key) {
+        log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname)?hostname:"-", "ACCESS DENIED - NO KEY");
+        error("STREAM [receive from [%s]:%s]: request without an API key. Forbidding access.", w->client_ip, w->client_port);
+        return rrdpush_receiver_permission_denied(w);
+    }
+
+    if(!hostname || !*hostname) {
+        log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname)?hostname:"-", "ACCESS DENIED - NO HOSTNAME");
+        error("STREAM [receive from [%s]:%s]: request without a hostname. Forbidding access.", w->client_ip, w->client_port);
+        return rrdpush_receiver_permission_denied(w);
+    }
+
+    if(!machine_guid || !*machine_guid) {
+        log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname)?hostname:"-", "ACCESS DENIED - NO MACHINE GUID");
+        error("STREAM [receive from [%s]:%s]: request without a machine GUID. Forbidding access.", w->client_ip, w->client_port);
+        return rrdpush_receiver_permission_denied(w);
+    }
+
+    if(regenerate_guid(key, buf) == -1) {
+        log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname)?hostname:"-", "ACCESS DENIED - INVALID KEY");
+        error("STREAM [receive from [%s]:%s]: API key '%s' is not valid GUID (use the command uuidgen to generate one). Forbidding access.", w->client_ip, w->client_port, key);
+        return rrdpush_receiver_permission_denied(w);
+    }
+
+    if(regenerate_guid(machine_guid, buf) == -1) {
+        log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname)?hostname:"-", "ACCESS DENIED - INVALID MACHINE GUID");
+        error("STREAM [receive from [%s]:%s]: machine GUID '%s' is not GUID. Forbidding access.", w->client_ip, w->client_port, machine_guid);
+        return rrdpush_receiver_permission_denied(w);
+    }
+
+    if(!appconfig_get_boolean(&stream_config, key, "enabled", 0)) {
+        log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname)?hostname:"-", "ACCESS DENIED - KEY NOT ENABLED");
+        error("STREAM [receive from [%s]:%s]: API key '%s' is not allowed. Forbidding access.", w->client_ip, w->client_port, key);
+        return rrdpush_receiver_permission_denied(w);
+    }
+
+    {
+        SIMPLE_PATTERN *key_allow_from = simple_pattern_create(appconfig_get(&stream_config, key, "allow from", "*"), NULL, SIMPLE_PATTERN_EXACT);
+        if(key_allow_from) {
+            if(!simple_pattern_matches(key_allow_from, w->client_ip)) {
+                simple_pattern_free(key_allow_from);
+                log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname) ? hostname : "-", "ACCESS DENIED - KEY NOT ALLOWED FROM THIS IP");
+                error("STREAM [receive from [%s]:%s]: API key '%s' is not permitted from this IP. Forbidding access.", w->client_ip, w->client_port, key);
+                return rrdpush_receiver_permission_denied(w);
+            }
+            simple_pattern_free(key_allow_from);
+        }
+    }
+
+    if(!appconfig_get_boolean(&stream_config, machine_guid, "enabled", 1)) {
+        log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname)?hostname:"-", "ACCESS DENIED - MACHINE GUID NOT ENABLED");
+        error("STREAM [receive from [%s]:%s]: machine GUID '%s' is not allowed. Forbidding access.", w->client_ip, w->client_port, machine_guid);
+        return rrdpush_receiver_permission_denied(w);
+    }
+
+    {
+        SIMPLE_PATTERN *machine_allow_from = simple_pattern_create(appconfig_get(&stream_config, machine_guid, "allow from", "*"), NULL, SIMPLE_PATTERN_EXACT);
+        if(machine_allow_from) {
+            if(!simple_pattern_matches(machine_allow_from, w->client_ip)) {
+                simple_pattern_free(machine_allow_from);
+                log_stream_connection(w->client_ip, w->client_port, (key && *key)?key:"-", (machine_guid && *machine_guid)?machine_guid:"-", (hostname && *hostname) ? hostname : "-", "ACCESS DENIED - MACHINE GUID NOT ALLOWED FROM THIS IP");
+                error("STREAM [receive from [%s]:%s]: Machine GUID '%s' is not permitted from this IP. Forbidding access.", w->client_ip, w->client_port, machine_guid);
+                return rrdpush_receiver_permission_denied(w);
+            }
+            simple_pattern_free(machine_allow_from);
+        }
+    }
+
+    if(unlikely(web_client_streaming_rate_t > 0)) {
+        static netdata_mutex_t stream_rate_mutex = NETDATA_MUTEX_INITIALIZER;
+        static volatile time_t last_stream_accepted_t = 0;
+
+        netdata_mutex_lock(&stream_rate_mutex);
+        time_t now = now_realtime_sec();
+
+        if(unlikely(last_stream_accepted_t == 0))
+            last_stream_accepted_t = now;
+
+        if(now - last_stream_accepted_t < web_client_streaming_rate_t) {
+            netdata_mutex_unlock(&stream_rate_mutex);
+            error("STREAM [receive from [%s]:%s]: too busy to accept new streaming request. Will be allowed in %ld secs.", w->client_ip, w->client_port, (long)(web_client_streaming_rate_t - (now - last_stream_accepted_t)));
+            return rrdpush_receiver_too_busy_now(w);
+        }
+
+        last_stream_accepted_t = now;
+        netdata_mutex_unlock(&stream_rate_mutex);
+    }
+
+    struct rrdpush_thread *rpt = callocz(1, sizeof(struct rrdpush_thread));
+    rpt->fd                = w->ifd;
+    rpt->key               = strdupz(key);
+    rpt->hostname          = strdupz(hostname);
+    rpt->registry_hostname = strdupz((registry_hostname && *registry_hostname)?registry_hostname:hostname);
+    rpt->machine_guid      = strdupz(machine_guid);
+    rpt->os                = strdupz(os);
+    rpt->timezone          = strdupz(timezone);
+    rpt->tags              = (tags)?strdupz(tags):NULL;
+    rpt->client_ip         = strdupz(w->client_ip);
+    rpt->client_port       = strdupz(w->client_port);
+    rpt->update_every      = update_every;
+
+    if(w->user_agent && w->user_agent[0]) {
+        char *t = strchr(w->user_agent, '/');
+        if(t && *t) {
+            *t = '\0';
+            t++;
+        }
+
+        rpt->program_name = strdupz(w->user_agent);
+        if(t && *t) rpt->program_version = strdupz(t);
+    }
+
+    netdata_thread_t thread;
+
+    debug(D_SYSTEM, "starting STREAM receive thread.");
+
+    char tag[FILENAME_MAX + 1];
+    snprintfz(tag, FILENAME_MAX, "STREAM_RECEIVER[%s,[%s]:%s]", rpt->hostname, w->client_ip, w->client_port);
+
+    if(netdata_thread_create(&thread, tag, NETDATA_THREAD_OPTION_DEFAULT, rrdpush_receiver_thread, (void *)rpt))
+        error("Failed to create new STREAM receive thread for client.");
+
+    // prevent the caller from closing the streaming socket
+    if(web_server_mode == WEB_SERVER_MODE_STATIC_THREADED) {
+        web_client_flag_set(w, WEB_CLIENT_FLAG_DONT_CLOSE_SOCKET);
+    }
+    else {
+        if(w->ifd == w->ofd)
+            w->ifd = w->ofd = -1;
+        else
+            w->ifd = -1;
+    }
+
+    buffer_flush(w->response.data);
+    return 200;
+}