From eaf8c7a28723dc81fc035e3a15a0ca1dbb46090c Mon Sep 17 00:00:00 2001 From: Florian Forster Date: Fri, 27 Nov 2015 12:49:44 +0100 Subject: [PATCH] statsd plugin: Implement the "CounterSum" option. Issues: #929, #1282, #1311 --- src/collectd.conf.in | 1 + src/collectd.conf.pod | 6 ++++++ src/statsd.c | 42 +++++++++++++++++++++++++++++------------- 3 files changed, 36 insertions(+), 13 deletions(-) diff --git a/src/collectd.conf.in b/src/collectd.conf.in index 30d536a1..b275ce1d 100644 --- a/src/collectd.conf.in +++ b/src/collectd.conf.in @@ -1132,6 +1132,7 @@ # DeleteTimers false # DeleteGauges false # DeleteSets false +# CounterSum false # TimerPercentile 90.0 # TimerPercentile 95.0 # TimerPercentile 99.0 diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod index 78a130cf..624cf410 100644 --- a/src/collectd.conf.pod +++ b/src/collectd.conf.pod @@ -6217,6 +6217,12 @@ rate of counters and size of sets will be zero, timers report C and gauges are unchanged. If set to B, the such metrics are not dispatched and removed from the internal cache. +=item B B|B + +When enabled, create a C metric which reports the change since the last +read. This option primarily exists for compatibility with the I +impelemtation by Etsy. + =item B I Calculate and dispatch the configured percentile, i.e. compute the latency, so diff --git a/src/statsd.c b/src/statsd.c index 8047b1a6..ea4123c1 100644 --- a/src/statsd.c +++ b/src/statsd.c @@ -64,6 +64,7 @@ struct statsd_metric_s { metric_type_t type; double value; + derive_t counter; latency_counter_t *latency; c_avl_tree_t *set; unsigned long updates_num; @@ -88,6 +89,7 @@ static _Bool conf_delete_sets = 0; static double *conf_timer_percentile = NULL; static size_t conf_timer_percentile_num = 0; +static _Bool conf_counter_sum = 0; static _Bool conf_timer_lower = 0; static _Bool conf_timer_upper = 0; static _Bool conf_timer_sum = 0; @@ -261,6 +263,8 @@ static int statsd_handle_counter (char const *name, /* {{{ */ if (status != 0) return (status); + /* Changes to the counter are added to (statsd_metric_t*)->value. ->counter is + * only updated in statsd_metric_submit_unsafe(). */ return (statsd_metric_add (name, (double) (value.gauge / scale.gauge), STATSD_COUNTER)); } /* }}} int statsd_handle_counter */ @@ -684,6 +688,8 @@ static int statsd_config (oconfig_item_t *ci) /* {{{ */ cf_util_get_boolean (child, &conf_delete_gauges); else if (strcasecmp ("DeleteSets", child->key) == 0) cf_util_get_boolean (child, &conf_delete_sets); + else if (strcasecmp ("CounterSum", child->key) == 0) + cf_util_get_boolean (child, &conf_counter_sum); else if (strcasecmp ("TimerLower", child->key) == 0) cf_util_get_boolean (child, &conf_timer_lower); else if (strcasecmp ("TimerUpper", child->key) == 0) @@ -754,8 +760,7 @@ static int statsd_metric_clear_set_unsafe (statsd_metric_t *metric) /* {{{ */ } /* }}} int statsd_metric_clear_set_unsafe */ /* Must hold metrics_lock when calling this function. */ -static int statsd_metric_submit_unsafe (char const *name, /* {{{ */ - statsd_metric_t const *metric) +static int statsd_metric_submit_unsafe (char const *name, statsd_metric_t *metric) /* {{{ */ { value_t values[1]; value_list_t vl = VALUE_LIST_INIT; @@ -851,17 +856,28 @@ static int statsd_metric_submit_unsafe (char const *name, /* {{{ */ values[0].gauge = (gauge_t) c_avl_size (metric->set); } else { /* STATSD_COUNTER */ - /* - * Expand a single value to two metrics: - * - * - The absolute counter, as a gauge - * - A derived rate for this counter - */ - values[0].derive = (derive_t) metric->value; - plugin_dispatch_values(&vl); - - sstrncpy(vl.type, "gauge", sizeof (vl.type)); - values[0].gauge = (gauge_t) metric->value; + gauge_t delta = nearbyint (metric->value); + + /* Etsy's statsd writes counters as two metrics: a rate and the change since + * the last write. Since collectd does not reset its DERIVE metrics to zero, + * this makes little sense, but we're dispatching a "count" metric here + * anyway - if requested by the user - for compatibility reasons. */ + if (conf_counter_sum) + { + sstrncpy (vl.type, "count", sizeof (vl.type)); + values[0].gauge = delta; + plugin_dispatch_values (&vl); + + /* restore vl.type */ + sstrncpy (vl.type, "derive", sizeof (vl.type)); + } + + /* Rather than resetting value to zero, subtract delta so we correctly keep + * track of residuals. */ + metric->value -= delta; + metric->counter += (derive_t) delta; + + values[0].derive = metric->counter; } return (plugin_dispatch_values (&vl)); -- 2.30.2