path: root/src/backends.c

#include "common.h"

#define BACKEND_SOURCE_DATA_AS_COLLECTED 0x00000001
#define BACKEND_SOURCE_DATA_AVERAGE      0x00000002
#define BACKEND_SOURCE_DATA_SUM          0x00000004

static inline calculated_number backend_calculate_value_from_stored_data(RRDSET *st, RRDDIM *rd, time_t after, time_t before, uint32_t options) {
    time_t first_t = rrdset_first_entry_t(st);
    time_t last_t = rrdset_last_entry_t(st);

    if(unlikely(before - after < st->update_every && after != after - after % st->update_every))
        // when st->update_every is bigger than the frequency we send data to backend
        // skip the iterations that are not aligned to the database
        return NAN;

    // align the time-frame
    // for 'after' also skip the first value by adding st->update_every
    after  = after  - after  % st->update_every + st->update_every;
    before = before - before % st->update_every;

    if(unlikely(after < first_t))
        after = first_t;

    if(unlikely(after > before))
        // this can happen when the st->update_every > before - after
        before = after;

    if(unlikely(before > last_t))
        before = last_t;

    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))) continue;

        calculated_number value = unpack_storage_number(n);
        sum += value;
        counter++;
    }

    if(unlikely(!counter))
        return NAN;

    if(unlikely(options & BACKEND_SOURCE_DATA_SUM))
        return sum;

    return sum / (calculated_number)counter;
}

static inline int format_dimension_collected_graphite_plaintext(BUFFER *b, const char *prefix, RRDHOST *host, const char *hostname, RRDSET *st, RRDDIM *rd, time_t after, time_t before, uint32_t options) {
    (void)host;
    (void)after;
    (void)before;
    (void)options;
    buffer_sprintf(b, "%s.%s.%s.%s " COLLECTED_NUMBER_FORMAT " %u\n", prefix, hostname, st->id, rd->id, rd->last_collected_value, (uint32_t)rd->last_collected_time.tv_sec);
    return 1;
}

static inline int format_dimension_stored_graphite_plaintext(BUFFER *b, const char *prefix, RRDHOST *host, const char *hostname, RRDSET *st, RRDDIM *rd, time_t after, time_t before, uint32_t options) {
    (void)host;
    calculated_number value = backend_calculate_value_from_stored_data(st, rd, after, before, options);
    if(!isnan(value)) {
        buffer_sprintf(b, "%s.%s.%s.%s " CALCULATED_NUMBER_FORMAT " %u\n", prefix, hostname, st->id, rd->id, value, (uint32_t) before);
        return 1;
    }
    return 0;
}

static inline int format_dimension_collected_opentsdb_telnet(BUFFER *b, const char *prefix, RRDHOST *host, const char *hostname, RRDSET *st, RRDDIM *rd, time_t after, time_t before, uint32_t options) {
    (void)host;
    (void)after;
    (void)before;
    (void)options;
    buffer_sprintf(b, "put %s.%s.%s %u " COLLECTED_NUMBER_FORMAT " host=%s\n", prefix, st->id, rd->id, (uint32_t)rd->last_collected_time.tv_sec, rd->last_collected_value, hostname);
    return 1;
}

static inline int format_dimension_stored_opentsdb_telnet(BUFFER *b, const char *prefix, RRDHOST *host, const char *hostname, RRDSET *st, RRDDIM *rd, time_t after, time_t before, uint32_t options) {
    (void)host;
    calculated_number value = backend_calculate_value_from_stored_data(st, rd, after, before, options);
    if(!isnan(value)) {
        buffer_sprintf(b, "put %s.%s.%s %u " CALCULATED_NUMBER_FORMAT " host=%s\n", prefix, st->id, rd->id, (uint32_t) before, value, hostname);
        return 1;
    }
    return 0;
}

static inline int process_graphite_response(BUFFER *b) {
    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("Received %zu bytes from graphite backend. Ignoring them. Sample: '%s'", buffer_strlen(b), sample);
    buffer_flush(b);
    return 0;
}

static inline int process_opentsdb_response(BUFFER *b) {
    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("Received %zu bytes from opentsdb backend. Ignoring them. Sample: '%s'", buffer_strlen(b), sample);
    buffer_flush(b);
    return 0;
}

void *backends_main(void *ptr) {
    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)ptr;

    BUFFER *b = buffer_create(1), *response = buffer_create(1);
    int (*backend_request_formatter)(BUFFER *b, const char *prefix, RRDHOST *host, const char *hostname, RRDSET *st, RRDDIM *rd, time_t after, time_t before, uint32_t options) = NULL;
    int (*backend_response_checker)(BUFFER *b) = NULL;

    info("BACKEND thread created with task id %d", gettid());

    if(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL) != 0)
        error("Cannot set pthread cancel type to DEFERRED.");

    if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
        error("Cannot set pthread cancel state to ENABLE.");

    // ------------------------------------------------------------------------
    // collect configuration options

    struct timeval timeout = {
            .tv_sec = 0,
            .tv_usec = 0
    };
    int default_port = 0;
    int sock = -1;
    uint32_t options;
    int enabled = config_get_boolean("backend", "enabled", 0);
    const char *source = config_get("backend", "data source", "average");
    const char *type = config_get("backend", "type", "graphite");
    const char *destination = config_get("backend", "destination", "localhost");
    const char *prefix = config_get("backend", "prefix", "netdata");
    const char *hostname = config_get("backend", "hostname", localhost.hostname);
    int frequency = (int)config_get_number("backend", "update every", 10);
    int buffer_on_failures = (int)config_get_number("backend", "buffer on failures", 10);
    long timeoutms = config_get_number("backend", "timeout ms", frequency * 2 * 1000);

    // ------------------------------------------------------------------------
    // validate configuration options
    // and prepare for sending data to our backend
    if(!enabled || frequency < 1)
        goto cleanup;

    if(!strcmp(source, "as collected")) {
        options = BACKEND_SOURCE_DATA_AS_COLLECTED;
    }
    else if(!strcmp(source, "average")) {
        options = BACKEND_SOURCE_DATA_AVERAGE;
    }
    else if(!strcmp(source, "sum") || !strcmp(source, "volume")) {
        options = BACKEND_SOURCE_DATA_SUM;
    }
    else {
        error("Invalid data source method '%s' for backend given. Disabling backed.", source);
        goto cleanup;
    }

    if(!strcmp(type, "graphite") || !strcmp(type, "graphite:plaintext")) {
        default_port = 2003;
        if(options == BACKEND_SOURCE_DATA_AS_COLLECTED)
            backend_request_formatter = format_dimension_collected_graphite_plaintext;
        else
            backend_request_formatter = format_dimension_stored_graphite_plaintext;

        backend_response_checker = process_graphite_response;
    }
    else if(!strcmp(type, "opentsdb") || !strcmp(type, "opentsdb:telnet")) {
        default_port = 4242;
        if(options == BACKEND_SOURCE_DATA_AS_COLLECTED)
            backend_request_formatter = format_dimension_collected_opentsdb_telnet;
        else
            backend_request_formatter = format_dimension_stored_opentsdb_telnet;

        backend_response_checker = process_opentsdb_response;
    }
    else {
        error("Unknown backend type '%s'", type);
        goto cleanup;
    }

    if(backend_request_formatter == NULL || backend_response_checker == NULL) {
        error("backend is misconfigured - disabling it.");
        goto cleanup;
    }

    if(timeoutms < 1) {
        error("BACKED invalid timeout %ld ms given. Assuming %d ms.", timeoutms, frequency * 2 * 1000);
        timeoutms = frequency * 2 * 1000;
    }
    timeout.tv_sec  = (timeoutms * 1000) / 1000000;
    timeout.tv_usec = (timeoutms * 1000) % 1000000;

    // ------------------------------------------------------------------------
    // prepare the charts for monitoring the backend

    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_find("netdata.backend_metrics");
    if(!chart_metrics) {
        chart_metrics = rrdset_create("netdata", "backend_metrics", NULL, "backend", NULL, "Netdata Buffered Metrics", "metrics", 130600, frequency, RRDSET_TYPE_LINE);
        rrddim_add(chart_metrics, "buffered", NULL,  1, 1, RRDDIM_ABSOLUTE);
        rrddim_add(chart_metrics, "lost",     NULL,  1, 1, RRDDIM_ABSOLUTE);
        rrddim_add(chart_metrics, "sent",     NULL,  1, 1, RRDDIM_ABSOLUTE);
    }

    RRDSET *chart_bytes = rrdset_find("netdata.backend_bytes");
    if(!chart_bytes) {
        chart_bytes = rrdset_create("netdata", "backend_bytes", NULL, "backend", NULL, "Netdata Backend Data Size", "KB", 130610, frequency, RRDSET_TYPE_AREA);
        rrddim_add(chart_bytes, "buffered", NULL, 1, 1024, RRDDIM_ABSOLUTE);
        rrddim_add(chart_bytes, "lost",     NULL, 1, 1024, RRDDIM_ABSOLUTE);
        rrddim_add(chart_bytes, "sent",     NULL, 1, 1024, RRDDIM_ABSOLUTE);
        rrddim_add(chart_bytes, "received", NULL, 1, 1024, RRDDIM_ABSOLUTE);
    }

    RRDSET *chart_ops = rrdset_find("netdata.backend_ops");
    if(!chart_ops) {
        chart_ops = rrdset_create("netdata", "backend_ops", NULL, "backend", NULL, "Netdata Backend Operations", "operations", 130630, frequency, RRDSET_TYPE_LINE);
        rrddim_add(chart_ops, "write",     NULL, 1, 1, RRDDIM_ABSOLUTE);
        rrddim_add(chart_ops, "discard",   NULL, 1, 1, RRDDIM_ABSOLUTE);
        rrddim_add(chart_ops, "reconnect", NULL, 1, 1, RRDDIM_ABSOLUTE);
        rrddim_add(chart_ops, "failure",   NULL, 1, 1, RRDDIM_ABSOLUTE);
        rrddim_add(chart_ops, "read",      NULL, 1, 1, RRDDIM_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_find("netdata.backend_latency");
    if(!chart_latency) {
        chart_latency = rrdset_create("netdata", "backend_latency", NULL, "backend", NULL, "Netdata Backend Latency", "ms", 130620, frequency, RRDSET_TYPE_AREA);
        rrddim_add(chart_latency, "latency",   NULL,  1, 1000, RRDDIM_ABSOLUTE);
    }
    */

    RRDSET *chart_rusage = rrdset_find("netdata.backend_thread_cpu");
    if(!chart_rusage) {
        chart_rusage = rrdset_create("netdata", "backend_thread_cpu", NULL, "backend", NULL, "NetData Backend Thread CPU usage", "milliseconds/s", 130630, frequency, RRDSET_TYPE_STACKED);
        rrddim_add(chart_rusage, "user",   NULL, 1, 1000, RRDDIM_INCREMENTAL);
        rrddim_add(chart_rusage, "system", NULL, 1, 1000, RRDDIM_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, frequency, hostname, prefix);

    usec_t step_ut = frequency * USEC_PER_SEC;
    usec_t random_ut = now_realtime_usec() % (step_ut / 2);
    time_t before = (time_t)((now_realtime_usec() - step_ut) / USEC_PER_SEC);
    time_t after = before;
    int failures = 0;

    for(;;) {
        // ------------------------------------------------------------------------
        // wait for the next iteration point

        usec_t now_ut = now_realtime_usec();
        usec_t next_ut = now_ut - (now_ut % step_ut) + step_ut;
        before = (time_t)(next_ut / USEC_PER_SEC);

        // add a little delay (1/4 of the step) plus some randomness
        next_ut += (step_ut / 4) + random_ut;

        while(now_ut < next_ut) {
            sleep_usec(next_ut - now_ut);
            now_ut = now_realtime_usec();
        }

        // ------------------------------------------------------------------------
        // add to the buffer the data we need to send to the backend

        RRDSET *st;
        int pthreadoldcancelstate;

        if(unlikely(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &pthreadoldcancelstate) != 0))
            error("Cannot set pthread cancel state to DISABLE.");

        rrdhost_rdlock(&localhost);
        for(st = localhost.rrdset_root; st ;st = st->next) {
            pthread_rwlock_rdlock(&st->rwlock);

            RRDDIM *rd;
            for(rd = st->dimensions; rd ;rd = rd->next) {
                if(rd->last_collected_time.tv_sec >= after)
                    chart_buffered_metrics += backend_request_formatter(b, prefix, &localhost, hostname, st, rd, after, before, options);
            }

            pthread_rwlock_unlock(&st->rwlock);
        }
        rrdhost_unlock(&localhost);

        if(unlikely(pthread_setcancelstate(pthreadoldcancelstate, NULL) != 0))
            error("Cannot set pthread cancel state to RESTORE (%d).", pthreadoldcancelstate);

        // ------------------------------------------------------------------------

        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);

        // ------------------------------------------------------------------------
        // 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("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_realtime_usec();
            const char *s = destination;
            while(*s) {
                const char *e = s;

                // skip separators, moving both s(tart) and e(nd)
                while(isspace(*e) || *e == ',') s = ++e;

                // move e(nd) to the first separator
                while(*e && !isspace(*e) && *e != ',') e++;

                // is there anything?
                if(!*s || s == e) break;

                char buf[e - s + 1];
                strncpyz(buf, s, e - s);
                chart_backend_reconnects++;
                sock = connect_to(buf, default_port, &timeout);
                if(sock != -1) break;
                s = e;
            }
            chart_backend_latency += now_realtime_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_realtime_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_realtime_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("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;
            }

            // either the buffer is empty
            // or is holding the data we couldn't send
            // so, make sure the next iteration will continue
            // from where we are now
            after = before;
        }
        else {
            error("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("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(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(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(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(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(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);

    info("BACKEND thread exiting");

    static_thread->enabled = 0;
    pthread_exit(NULL);
    return NULL;
}