Dynamic Stats ============= Rsyslog produces runtime-stats to allow user to study service health, performance, bottlenecks etc. Runtime-stats counters that Rsyslog components publish are statically defined. **Dynamic Stats** (called dyn-stats henceforth) component allows user to configure stats-namespaces (called stats-buckets) and increment counters within these buckets using Rainerscript function call. The metric-name in this case can be a message-property or a sub-string extracted from message etc. Dyn-stats configuration ^^^^^^^^^^^^^^^^^^^^^^^ Dyn-stats configuration involves a **two part setup**. dyn_stats(name=""...) (object) -------------------------------------- **Defines** the bucket(identified by the bucket-name) and allows user to set some properties that control behavior of the bucket. :: dyn_stats(name="msg_per_host") Parameters: **name** : Name of the bucket. **resettable** : Whether or not counters should be reset every time they are reported. This works independent of ``resetCounters`` config parameter in :doc:`modules/impstats`. **maxCardinality** : Maximum number of unique counter-names to track. **unusedMetricLife** : Interval between full purges (in seconds). This prevents unused counters from occupying resources forever. A definition setting all the parameters looks like: :: dyn_stats(name="msg_per_host" resettable="on" maxCardinality="3000" unusedMetricLife="600") dyn_inc("", ) (function) -------------------------------------- **Increments** counter identified by value of variable in bucket identified by name. Parameters: **name** : Name of the bucket **expr** : Name of counter (this name will be reported by impstats to identify the counter) A ``dyn_inc`` call looks like: :: set $.inc = dyn_inc("msg_per_host", $hostname); if ($.inc != 0) then { .... } ``$.inc`` captures the error-code. It has value ``0`` when increment operation is successful and non-zero when it fails. It uses Rsyslog error-codes. Reporting ^^^^^^^^^ Legacy format: :: ... global: origin=dynstats msg_per_host.ops_overflow=1 msg_per_host.new_metric_add=3 msg_per_host.no_metric=0 msg_per_host.metrics_purged=0 msg_per_host.ops_ignored=0 ... msg_per_host: origin=dynstats.bucket foo=2 bar=1 baz=1 ... Json(variants with the same structure are used in other Json based formats such as ``cee`` and ``json-elasticsearch``) format: :: ... { "name": "global", "origin": "dynstats", "values": { "msg_per_host.ops_overflow": 1, "msg_per_host.new_metric_add": 3, "msg_per_host.no_metric": 0, "msg_per_host.metrics_purged": 0, "msg_per_host.ops_ignored": 0 } } ... { "name": "msg_per_host", "origin": "dynstats.bucket", "values": { "foo": 2, "bar": 1, "baz": 1 } } ... In this case counters are encapsulated inside an object hanging off top-level-key ``values``. Fields ------ **global: origin=dynstats**: **ops_overflow**: Number of operations ignored because number-of-counters-tracked has hit configured max-cardinality. **new_metric_add**: Number of "new" metrics added (new counters created). **no_metric**: Counter-name given was invalid (length = 0). **metrics_purged**: Number of counters discarded at discard-cycle (controlled by **unusedMetricLife**). **ops_ignored**: Number of operations ignored due to potential performance overhead. Dyn-stats subsystem ignores operations to avoid performance-penalty if it can't get access to counter without delay(lock acquiring latency). **purge_triggered**: Indicates that a discard was performed (1 implies a discard-cycle run). **msg_per_host: origin=dynstats.bucket**: ****: Value of counter identified by .