write_graphite plugin: Adding LogSendErrors boolean flag

Sometimes we don't want to hog the syslog with errors that are produced
when the graphite server is down.

Especially for UDP, we want to be able to truly fire-and-forget
(remember to monitor UDP packet receipt failures though :) and having
errors written to the syslog is a burden that should be avoided.

diff --git a/src/write_graphite.c b/src/write_graphite.c
index 80f52d3..546111b 100644 (file)
--- a/src/write_graphite.c
+++ b/src/write_graphite.c
@@ -36,6 +36,7 @@
   *     Host "localhost"
   *     Port "2003"
   *     Protocol "udp"
+  *     LogSendErrors true
   *     Prefix "collectd"
   *   </Carbon>
   * </Plugin>
@@ -69,6 +70,10 @@
 # define WG_DEFAULT_PROTOCOL "udp"
 #endif
 
+#ifndef WG_DEFAULT_LOG_SEND_ERRORS
+# define WG_DEFAULT_LOG_SEND_ERRORS 1
+#endif
+
 #ifndef WG_DEFAULT_ESCAPE
 # define WG_DEFAULT_ESCAPE '_'
 #endif
@@ -90,6 +95,7 @@ struct wg_callback
     char    *node;
     char    *service;
     char    *protocol;
+    _Bool   log_send_errors;
     char    *prefix;
     char    *postfix;
     char     escape_char;
@@ -122,7 +128,7 @@ static int wg_send_buffer (struct wg_callback *cb)
     ssize_t status = 0;
 
     status = swrite (cb->sock_fd, cb->send_buf, strlen (cb->send_buf));
-    if (status < 0)
+    if (cb->log_send_errors && status < 0)
     {
         char errbuf[1024];
         ERROR ("write_graphite plugin: send to %s:%s (%s) failed with status %zi (%s)",
@@ -463,6 +469,7 @@ static int wg_config_node (oconfig_item_t *ci)
     cb->node = NULL;
     cb->service = NULL;
     cb->protocol = NULL;
+    cb->log_send_errors = WG_DEFAULT_LOG_SEND_ERRORS;
     cb->prefix = NULL;
     cb->postfix = NULL;
     cb->escape_char = WG_DEFAULT_ESCAPE;
@@ -492,6 +499,8 @@ static int wg_config_node (oconfig_item_t *ci)
             cf_util_get_service (child, &cb->service);
         else if (strcasecmp ("Protocol", child->key) == 0)
             cf_util_get_string (child, &cb->protocol);
+        else if (strcasecmp ("LogSendErrors", child->key) == 0)
+            cf_util_get_boolean (child, &cb->log_send_errors);
         else if (strcasecmp ("Prefix", child->key) == 0)
             cf_util_get_string (child, &cb->prefix);
         else if (strcasecmp ("Postfix", child->key) == 0)