backend buffer should always be incremental

[netdata.git] / src / backends.c

diff --git a/src/backends.c b/src/backends.c
index 1272d0473d585d01c38ab77de132025170884dbc..4250e31c4b2d89e95e551680886bfd61fc466d9d 100644 (file)
--- a/src/backends.c
+++ b/src/backends.c
@@ -292,30 +292,19 @@ void *backends_main(void *ptr) {
     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;
+    time_t after = now_realtime_sec();
     int failures = 0;
+    heartbeat_t hb;
+    heartbeat_init(&hb);
 
     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();
-        }
+        // Wait for the next iteration point.
+        heartbeat_next(&hb, step_ut);
+        time_t before = now_realtime_sec();
 
         // ------------------------------------------------------------------------
         // add to the buffer the data we need to send to the backend
-
         RRDSET *st;
         int pthreadoldcancelstate;
 
@@ -360,6 +349,10 @@ void *backends_main(void *ptr) {
         //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
 
@@ -399,7 +392,7 @@ void *backends_main(void *ptr) {
         // if we are not connected, connect to a backend server
 
         if(unlikely(sock == -1)) {
-            usec_t start_ut = now_realtime_usec();
+            usec_t start_ut = now_monotonic_usec();
             const char *s = destination;
             while(*s) {
                 const char *e = s;
@@ -420,7 +413,7 @@ void *backends_main(void *ptr) {
                 if(sock != -1) break;
                 s = e;
             }
-            chart_backend_latency += now_realtime_usec() - start_ut;
+            chart_backend_latency += now_monotonic_usec() - start_ut;
         }
 
         if(unlikely(netdata_exit)) break;
@@ -430,14 +423,14 @@ void *backends_main(void *ptr) {
 
         if(likely(sock != -1)) {
             size_t len = buffer_strlen(b);
-            usec_t start_ut = now_realtime_usec();
+            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_realtime_usec() - start_ut;
+            chart_backend_latency += now_monotonic_usec() - start_ut;
             if(written != -1 && (size_t)written == len) {
                 // we sent the data successfully
                 chart_transmission_successes++;
@@ -465,12 +458,6 @@ void *backends_main(void *ptr) {
                 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);