From: Florian Forster <octo@collectd.org>
Date: Mon, 8 Sep 2014 15:11:56 +0000 (+0200)
Subject: Merge remote-tracking branch 'github/master'
X-Git-Tag: collectd-5.5.0~204
X-Git-Url: https://git.octo.it/?a=commitdiff_plain;h=67411e0794cfcab38e322b2ebbe2e5207cbdd86a;hp=c0a9b7b38edf881e134f602b62990518a79bf191;p=collectd.git

Merge remote-tracking branch 'github/master'
---

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index c9310ee0..7c9860f0 100644
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -25,6 +25,13 @@
 #AutoLoadPlugin false
 
 #----------------------------------------------------------------------------#
+# When enabled, internal statistics are collected, using "collectd" as the   #
+# plugin name.                                                               #
+# Disabled by default.                                                       #
+#----------------------------------------------------------------------------#
+#CollectInternalStats false
+
+#----------------------------------------------------------------------------#
 # Interval at which to query values. This may be overwritten on a per-plugin #
 # base by using the 'Interval' option of the LoadPlugin block:               #
 #   <LoadPlugin foo>                                                         #
diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index d38c5c94..cabbb526 100644
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -146,6 +146,18 @@ B<E<lt>PluginE<nbsp>...E<gt>> block acts as if it was immediately preceded by a
 B<LoadPlugin> statement. B<LoadPlugin> statements are still required for
 plugins that don't provide any configuration, e.g. the I<Load plugin>.
 
+=item B<CollectInternalStats> B<false>|B<true>
+
+When set to B<true>, various statistics about the I<collectd> daemon will be
+collected, with "collectd" as the I<plugin name>. Defaults to B<false>.
+
+The "write_queue" I<plugin instance> reports the number of elements currently
+queued and the number of elements dropped off the queue by the
+B<WriteQueueLimitLow>/B<WriteQueueLimitHigh> mechanism.
+
+The "cache" I<plugin instance> reports the number of elements in the value list
+cache (the cache you can interact with using L<collectd-unixsock(5)>).
+
 =item B<Include> I<Path> [I<pattern>]
 
 If I<Path> points to a file, includes that file. If I<Path> points to a
@@ -276,8 +288,11 @@ If B<WriteQueueLimitHigh> is set to non-zero and B<WriteQueueLimitLow> is
 unset, the latter will default to half of B<WriteQueueLimitHigh>.
 
 If you do not want to randomly drop values when the queue size is between
-I<LowNum> and I<HighNum>, set If B<WriteQueueLimitHigh> and
-B<WriteQueueLimitLow> to same value.
+I<LowNum> and I<HighNum>, set B<WriteQueueLimitHigh> and B<WriteQueueLimitLow>
+to the same value.
+
+Enabling the B<CollectInternalStats> option is of great help to figure out the
+values to set B<WriteQueueLimitHigh> and B<WriteQueueLimitLow> to.
 
 =item B<Hostname> I<Name>
 
diff --git a/src/configfile.c b/src/configfile.c
index 9a5807ce..9841efda 100644
--- a/src/configfile.c
+++ b/src/configfile.c
@@ -117,6 +117,7 @@ static cf_global_option_t cf_global_options[] =
 	{"WriteQueueLimitLow", NULL, NULL},
 	{"Timeout",     NULL, "2"},
 	{"AutoLoadPlugin", NULL, "false"},
+	{"CollectInternalStats", NULL, "false"},
 	{"PreCacheChain",  NULL, "PreCache"},
 	{"PostCacheChain", NULL, "PostCache"},
 	{"MaxReadInterval", NULL, "86400"}
diff --git a/src/plugin.c b/src/plugin.c
index 5b9763ab..cd992044 100644
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -131,6 +131,9 @@ static _Bool           plugin_ctx_key_initialized = 0;
 static long            write_limit_high = 0;
 static long            write_limit_low = 0;
 
+static derive_t        stats_values_dropped = 0;
+static _Bool           record_statistics = 0;
+
 /*
  * Static functions
  */
@@ -144,6 +147,52 @@ static const char *plugin_get_dir (void)
 		return (plugindir);
 }
 
+static void plugin_update_internal_statistics (void) { /* {{{ */
+	derive_t copy_write_queue_length;
+	value_list_t vl = VALUE_LIST_INIT;
+	value_t values[2];
+
+	copy_write_queue_length = write_queue_length;
+
+	/* Initialize `vl' */
+	vl.values = values;
+	vl.values_len = 2;
+	vl.time = 0;
+	sstrncpy (vl.host, hostname_g, sizeof (vl.host));
+	sstrncpy (vl.plugin, "collectd", sizeof (vl.plugin));
+
+	vl.type_instance[0] = 0;
+	vl.values_len = 1;
+
+	/* Write queue */
+	sstrncpy (vl.plugin_instance, "write_queue",
+			sizeof (vl.plugin_instance));
+
+	/* Write queue : queue length */
+	vl.values[0].gauge = (gauge_t) copy_write_queue_length;
+	sstrncpy (vl.type, "queue_length", sizeof (vl.type));
+	vl.type_instance[0] = 0;
+	plugin_dispatch_values (&vl);
+
+	/* Write queue : Values dropped (queue length > low limit) */
+	vl.values[0].derive = (derive_t) stats_values_dropped;
+	sstrncpy (vl.type, "derive", sizeof (vl.type));
+	sstrncpy (vl.type_instance, "dropped", sizeof (vl.type_instance));
+	plugin_dispatch_values (&vl);
+
+	/* Cache */
+	sstrncpy (vl.plugin_instance, "cache",
+			sizeof (vl.plugin_instance));
+
+	/* Cache : Nb entry in cache tree */
+	vl.values[0].gauge = (gauge_t) uc_get_size();
+	sstrncpy (vl.type, "cache_size", sizeof (vl.type));
+	vl.type_instance[0] = 0;
+	plugin_dispatch_values (&vl);
+
+	return;
+} /* }}} void plugin_update_internal_statistics */
+
 static void destroy_callback (callback_func_t *cf) /* {{{ */
 {
 	if (cf == NULL)
@@ -1472,6 +1521,9 @@ void plugin_init_all (void)
 	/* Init the value cache */
 	uc_init ();
 
+	if (IS_TRUE (global_option_get ("CollectInternalStats")))
+		record_statistics = 1;
+
 	chain_name = global_option_get ("PreCacheChain");
 	pre_cache_chain = fc_chain_get_by_name (chain_name);
 
@@ -1564,6 +1616,9 @@ void plugin_init_all (void)
 /* TODO: Rename this function. */
 void plugin_read_all (void)
 {
+	if(record_statistics) {
+		plugin_update_internal_statistics ();
+	}
 	uc_check_timeout ();
 
 	return;
@@ -2085,9 +2140,16 @@ static _Bool check_drop_value (void) /* {{{ */
 int plugin_dispatch_values (value_list_t const *vl)
 {
 	int status;
+	static pthread_mutex_t statistics_lock = PTHREAD_MUTEX_INITIALIZER;
 
-	if (check_drop_value ())
+	if (check_drop_value ()) {
+		if(record_statistics) {
+			pthread_mutex_lock(&statistics_lock);
+			stats_values_dropped++;
+			pthread_mutex_unlock(&statistics_lock);
+		}
 		return (0);
+	}
 
 	status = plugin_write_enqueue (vl);
 	if (status != 0)
diff --git a/src/utils_cache.c b/src/utils_cache.c
index 9d867815..fe22f211 100644
--- a/src/utils_cache.c
+++ b/src/utils_cache.c
@@ -570,6 +570,16 @@ gauge_t *uc_get_rate (const data_set_t *ds, const value_list_t *vl)
   return (ret);
 } /* gauge_t *uc_get_rate */
 
+size_t uc_get_size() {
+  size_t size_arrays = 0;
+
+  pthread_mutex_lock (&cache_lock);
+  size_arrays = (size_t) c_avl_size (cache_tree);
+  pthread_mutex_unlock (&cache_lock);
+
+  return (size_arrays);
+}
+
 int uc_get_names (char ***ret_names, cdtime_t **ret_times, size_t *ret_number)
 {
   c_avl_iterator_t *iter;
diff --git a/src/utils_cache.h b/src/utils_cache.h
index 16039aa8..ea3eb2f4 100644
--- a/src/utils_cache.h
+++ b/src/utils_cache.h
@@ -40,6 +40,7 @@ int uc_update (const data_set_t *ds, const value_list_t *vl);
 int uc_get_rate_by_name (const char *name, gauge_t **ret_values, size_t *ret_values_num);
 gauge_t *uc_get_rate (const data_set_t *ds, const value_list_t *vl);
 
+size_t uc_get_size();
 int uc_get_names (char ***ret_names, cdtime_t **ret_times, size_t *ret_number);
 
 int uc_get_state (const data_set_t *ds, const value_list_t *vl);