MongooseIM metrics¶

MongooseIM by default collects many metrics showing the user behaviour and general system statistics.

Metrics are exposed in the Prometheus format, or they are managed by ESL's fork of the Exometer project. Both can be configured in the instrumentation section. There are some differences between the two systems, when it comes to conventions, naming and metric types.

In the default configuration file, Prometheus metrics are enabled, and available at the http://127.0.0.1:9091/metrics endpoint.

All metrics are divided into the following groups:

Per host type metrics: Gathered separately for every host type supported by the cluster.

Warning

If a cluster supports many (thousands or more) host types, performance issues might occur. To avoid this, when using Exometer, use global equivalents of the metrics with all_metrics_are_global config option.
Global metrics: Metrics common for all host types.
- Data metrics. These are misc. metrics related to data transfers (e.g. sent and received stanza size statistics).
- VM metrics. Basic Erlang VM statistics.
Backend metrics: Histograms with timings of calls to various backends.

Metrics types¶

PrometheusExometer

`counter`

A monotonically increasing metric type. It is used for events like the number of stanzas processed by the system.

Example:

# TYPE c2s_element_in_message_count counter
# HELP c2s_element_in_message_count Event: c2s_element_in, Metric: message_count
c2s_element_in_message_count{host_type="localhost"} 0

`gauge`

A metric that represents a current value in the system.

Example:

# TYPE mnesia_info_running_db_nodes gauge
# HELP mnesia_info_running_db_nodes Event: mnesia_info, Metric: running_db_nodes
mnesia_info_running_db_nodes 0

`histogram`

A histogram collects values and groups them in buckets.

Example:

# TYPE c2s_xmpp_element_size_in_byte_size histogram
# HELP c2s_xmpp_element_size_in_byte_size Event: c2s_xmpp_element_size_in, Metric: byte_size
c2s_xmpp_element_size_in_byte_size_bucket{le="1"} 0
...
c2s_xmpp_element_size_in_byte_size_bucket{le="1073741824"} 0
c2s_xmpp_element_size_in_byte_size_bucket{le="+Inf"} 0

`spiral`

This kind of metric provides 2 values: total event count (e.g. stanzas processed) and a value in 60s window (one value). Dividing one value by 60 provides an average per-second value over last minute.

Example: [{total, 1000}, {one, 20}]

`counter`

A simple monotonically increasing value. It consists of two properties:

Example: [{value, 12}, {ms_since_reset, 91761}]

`gauge`

It is similar to a counter type but can be set to any value.

value
ms_since_reset - Time in milliseconds elapsed from the last metric update.

Example: [{value, 12}, {ms_since_reset, 91761}]

`histogram`

A histogram collects values over a sliding window of 60s and exposes the following stats:

n - A number of samples.
mean - An arithmetic mean.
min
max
median
50, 75, 90, 95, 99, 999 - 50th, 75th, 90th, 95th, 99th and 99.9th percentile

Per host type metrics¶

Prometheus metrics have a host_type label associated with these metrics. Since Exometer doesn't support labels, the host types are part of the metric names.

Presences & rosters¶

PrometheusExometer

Name	Type	Description (when it gets incremented)
`sm_presence_subscription_subscription_count`	counter	Presence subscription is processed.
`sm_presence_subscription_unsubscription_count`	counter	Presence unsubscription is processed.
`mod_roster_get_count`	counter	User's roster is fetched.
`mod_roster_push_count`	counter	A roster update is pushed to a single session.
`mod_roster_set_count`	counter	User's roster is updated.

Name	Type	Description (when it gets incremented)
`[HostType, sm_presence_subscription, subscription_count]`	spiral	Presence subscription is processed.
`[HostType, sm_presence_subscription, unsubscription_count]`	spiral	Presence unsubscription is processed.
`[HostType, mod_roster_get, count]`	spiral	User's roster is fetched.
`[HostType, mod_roster_push, count]`	spiral	A roster update is pushed to a single session.
`[HostType, mod_roster_set, count]`	spiral	User's roster is updated.

Privacy lists¶

PrometheusExometer

Name	Type	Description (when it gets incremented)
`mod_privacy_get_count`	counter	IQ privacy `get` is processed.
`mod_privacy_push_item_count`	counter	Privacy list update is sent to a single session.
`mod_privacy_set_count`	counter	IQ privacy `set` is processed.
`mod_privacy_set_active_count`	counter	Active privacy list is changed.
`mod_privacy_set_default_count`	counter	Default privacy list is changed.
`mod_privacy_check_packet_count`	counter	A packet is checked against the privacy list.
`mod_privacy_check_packet_denied_count`	counter	Privacy list check resulted in `deny`.
`mod_privacy_check_packet_blocked_count`	counter	Privacy list check resulted in `block`.

Name	Type	Description (when it gets incremented)
`[HostType, mod_privacy_get, count]`	spiral	IQ privacy `get` is processed.
`[HostType, mod_privacy_push_item, count]`	spiral	Privacy list update is sent to a single session.
`[HostType, mod_privacy_set, count]`	spiral	IQ privacy `set` is processed.
`[HostType, mod_privacy_set, active_count]`	spiral	Active privacy list is changed.
`[HostType, mod_privacy_set, default_count]`	spiral	Default privacy list is changed.
`[HostType, mod_privacy_check_packet, count]`	spiral	A packet is checked against the privacy list.
`[HostType, mod_privacy_check_packet, denied_count]`	spiral	Privacy list check resulted in `deny`.
`[HostType, mod_privacy_check_packet, blocked_count]`	spiral	Privacy list check resulted in `block`.

Other¶

PrometheusExometer

Name	Type	Description (when it gets incremented)
`c2s_auth_failed_count`	counter	A client failed to authenticate.
`sm_session_count`	gauge	Number of active sessions.
`sm_session_logouts`	counter	A client session is closed.
`sm_session_logins`	counter	A client session is opened.
`c2s_element_in_count`	counter	An XML element is received from a client.
`c2s_element_in_stanza_count`	counter	An XMPP stanza is received from a client.
`c2s_element_in_message_count`	counter	A message stanza is received from a client.
`c2s_element_in_iq_count`	counter	An IQ stanza is received from a client.
`c2s_element_in_presence_count`	counter	A presence stanza is received from a client.
`c2s_element_in_error_count`	counter	An error is received from a client.
`c2s_element_in_message_error_count`	counter	A message error is received from a client.
`c2s_element_in_iq_error_count`	counter	An IQ error is received from a client.
`c2s_element_in_presence_error_count`	counter	A presence error is received from a client.
`c2s_element_out_count`	counter	An XML element is sent to a client.
`c2s_element_out_stanza_count`	counter	An XMPP stanza is sent to a client.
`c2s_element_out_iq_count`	counter	An IQ stanza is sent to a client.
`c2s_element_out_message_count`	counter	A message stanza is sent to a client.
`c2s_element_out_presence_count`	counter	A presence stanza is sent to a client.
`c2s_element_out_error_count`	counter	An error is sent to a client.
`c2s_element_out_iq_error_count`	counter	An IQ error is sent to a client.
`c2s_element_out_message_error_count`	counter	A message error is sent to a client.
`c2s_element_out_presence_error_count`	counter	A presence error is sent to a client.
`c2s_message_processed_time`	histogram	Processing time for incoming c2s stanzas.
`sm_message_bounced_count`	counter	A `service-unavailable` error is sent, because the message recipient is offline.
`router_stanza_dropped_count`	counter	A stanza is dropped due to an AMP rule or a `filter_local_packet` processing flow.
`router_no_route_found_count`	counter	It is not possible to route a stanza (all routing handlers failed).

Name	Type	Description (when it gets incremented)
`[HostType, c2s_auth_failed, count]`	spiral	A client failed to authenticate.
`[HostType, sm_session, count]`	counter	Number of active sessions.
`[HostType, sm_session, logouts]`	spiral	A client session is closed.
`[HostType, sm_session, logins]`	spiral	A client session is opened.
`[HostType, c2s_element_in, count]`	spiral	An XML element is received from a client.
`[HostType, c2s_element_in, stanza_count]`	spiral	An XMPP stanza is received from a client.
`[HostType, c2s_element_in, message_count]`	spiral	A message stanza is received from a client.
`[HostType, c2s_element_in, iq_count]`	spiral	An IQ stanza is received from a client.
`[HostType, c2s_element_in, presence_count]`	spiral	A presence stanza is received from a client.
`[HostType, c2s_element_in, error_count]`	spiral	An error is received from a client.
`[HostType, c2s_element_in, message_error_count]`	spiral	A message error is received from a client.
`[HostType, c2s_element_in, iq_error_count]`	spiral	An IQ error is received from a client.
`[HostType, c2s_element_in, presence_error_count]`	spiral	A presence error is received from a client.
`[HostType, c2s_element_out, count]`	spiral	An XML element is sent to a client.
`[HostType, c2s_element_out, stanza_count]`	spiral	An XMPP stanza is sent to a client.
`[HostType, c2s_element_out, iq_count]`	spiral	An IQ stanza is sent to a client.
`[HostType, c2s_element_out, message_count]`	spiral	A message stanza is sent to a client.
`[HostType, c2s_element_out, presence_count]`	spiral	A presence stanza is sent to a client.
`[HostType, c2s_element_out, error_count]`	spiral	An error is sent to a client.
`[HostType, c2s_element_out, iq_error_count]`	spiral	An IQ error is sent to a client.
`[HostType, c2s_element_out, message_error_count]`	spiral	A message error is sent to a client.
`[HostType, c2s_element_out, presence_error_count]`	spiral	A presence error is sent to a client.
`[HostType, c2s_message_processing_time`]	histogram	Processing time for incoming c2s stanzas.
`[HostType, sm_message_bounced, count]`	spiral	A `service-unavailable` error is sent, because the message recipient is offline.
`[HostType, router_stanza_dropped, count]`	spiral	A stanza is dropped due to an AMP rule or a `filter_local_packet` processing flow.
`[HostType, router_no_route_found, count]`	spiral	It is not possible to route a stanza (all routing handlers failed).

Pool metrics¶

For every RDBMS pool defined, an instance of these metrics are available. Prometheus metrics have a host_type and pool_tag labels associated with these metrics. Since Exometer doesn't support labels, the host types and tags are part of the metric names.

PrometheusExometer

Name	Type	Description (when it gets incremented)
`wpool_rdbms_stats_workers`	gauge	Number of workers in the pool
`wpool_rdbms_stats_recv_oct`	counter	Number of bytes received
`wpool_rdbms_stats_recv_cnt`	counter	Number of packets received
`wpool_rdbms_stats_recv_max`	gauge	Size of the largest packet, in bytes
`wpool_rdbms_stats_send_oct`	counter	Number of bytes sent
`wpool_rdbms_stats_send_max`	gauge	Size of the largest packet
`wpool_rdbms_stats_send_cnt`	counter	Number of packets sent
`wpool_rdbms_stats_send_pend`	counter	Number of bytes waiting to be sent

Name	Type	Description (when it gets incremented)
`[HostType, wpool_rdbms_stats, PoolTag, workers]`	counter	Number of workers in the pool
`[HostType, wpool_rdbms_stats, PoolTag, recv_oct]`	spiral	Number of bytes received
`[HostType, wpool_rdbms_stats, PoolTag, recv_cnt]`	spiral	Number of packets received
`[HostType, wpool_rdbms_stats, PoolTag, recv_max]`	gauge	Size of the largest packet, in bytes
`[HostType, wpool_rdbms_stats, PoolTag, send_oct]`	spiral	Number of bytes sent
`[HostType, wpool_rdbms_stats, PoolTag, send_max]`	gauge	Size of the largest packet
`[HostType, wpool_rdbms_stats, PoolTag, send_cnt]`	spiral	Number of packets sent
`[HostType, wpool_rdbms_stats, PoolTag, send_pend]`	spiral	Number of bytes waiting to be sent

When using a Rabbit worker pool, metrics defined in mod_event_pusher_rabbit are available.

Extension-specific metrics¶

Metrics specific to an extension, e.g. Message Archive Management, are described in respective module documentation pages.

Global metrics¶

All of these metrics are updated periodically. The interval at which they are probed can be configured with the [instrumentation.probe_interval option].

PrometheusExometer

Name	Type	Description
`sm_node_sessions_count`	gauge	A number of sessions connected to a given MongooseIM node.
`sm_total_sessions_count`	gauge	A number of sessions connected to a MongooseIM cluster.
`sm_unique_sessions_count`	gauge	A number of unique users connected to a MongooseIM cluster (e.g. 3 sessions of the same user will be counted as 1 in this metric).
`system_up_time_seconds`	gauge	Node uptime.
`mnesia_info_running_db_nodes`	gauge	A number of nodes in a MongooseIM cluster seen by a given MongooseIM node (based on Mnesia). For CETS, use `cets_info, joined_nodes` instead.
`system_tcp_ports_count`	gauge	A number of open tcp connections. This should relate to the number of connected sessions and databases, as well as federations and http requests. A constantly growing value might indicate a connection leak.
`system_process_queue_lengths_total`	gauge	The total number of incoming messages queued in the Erlang processes. It is a good indicator of an overloaded system: if too many messages are queued at the same time, the system is most likely overloaded with incoming data.
`system_dist_data_Metric`	gauge	Network stats for Erlang distributed communication. `Metric` can be `recv_oct`, `recv_cnt`, `recv_max`, `send_oct`, `send_max`, `send_cnt`, `send_pend` or `connections`.

Name	Type	Description
`[global, sm_node_sessions, count]`	gauge	A number of sessions connected to a given MongooseIM node.
`[global, sm_total_sessions, count]`	gauge	A number of sessions connected to a MongooseIM cluster.
`[global, sm_unique_sessions, count]`	gauge	A number of unique users connected to a MongooseIM cluster (e.g. 3 sessions of the same user will be counted as 1 in this metric).
`[global, system_up_time, seconds]`	gauge	Node uptime.
`[global, mnesia_info, running_db_nodes]`	gauge	A number of nodes in a MongooseIM cluster seen by a given MongooseIM node (based on Mnesia). For CETS, use `[global, cets_info, joined_nodes]` instead.
`[global, system_tcp_ports, count]`	gauge	A number of open tcp connections. This should relate to the number of connected sessions and databases, as well as federations and http requests. A constantly growing value might indicate a connection leak.
`[global, system_process_queue_lengths, total]`	probe	The total number of incoming messages queued in the Erlang processes. It is a good indicator of an overloaded system: if too many messages are queued at the same time, the system is most likely overloaded with incoming data.
`[global, system_dist_data, Metric]`	gauge	Network stats for Erlang distributed communication. `Metric` can be `recv_oct`, `recv_cnt`, `recv_max`, `send_oct`, `send_max`, `send_cnt`, `send_pend` or `connections`.

Data metrics¶

All metrics are in bytes, and refer to unencrypted data (before encryption or after decryption in case of TLS).

PrometheusExometer

Metric name	Type	Description
`c2s_xmpp_element_size_in_byte_size`	histogram	Size of an XML element received from a client.
`c2s_xmpp_element_size_out_byte_size`	histogram	Size of an XML element sent to a client.
`c2s_tcp_data_in_byte_size`	counter	Amount of data received from a client via TCP channel.
`c2s_tcp_data_out_byte_size`	counter	Amount of data sent to a client via TCP channel.
`c2s_tls_data_in_byte_size`	counter	Amount of data received from a client via TLS channel.
`c2s_tls_data_out_byte_size`	counter	Amount of data sent to a client via TLS channel.
`mod_bosh_data_received_byte_size`	counter	Amount of data received from a client via BOSH connection.
`mod_bosh_data_sent_byte_size`	counter	Amount of data sent to a client via BOSH connection.
`mod_websocket_data_received_byte_size`	counter	Amount of data received from a client via WebSocket connection.
`mod_websocket_data_sent_byte_size`	counter	Amount of data sent to a client via WebSocket connection.
`s2s_xmpp_element_size_in_byte_size`	histogram	Size of an XML element received from another XMPP server.
`s2s_xmpp_element_size_out_byte_size`	histogram	Size of an XML element sent to another XMPP server.
`s2s_tcp_data_in_byte_size`	counter	Amount of data received from another XMPP server via TCP channel.
`s2s_tcp_data_out_byte_size`	counter	Amount of data sent to another XMPP server via TCP channel.
`s2s_tls_data_in_byte_size`	counter	Amount of data received from another XMPP server via TLS channel.
`s2s_tls_data_out_byte_size`	counter	Amount of data sent to another XMPP server via TLS channel.
`component_xmpp_element_size_in_byte_size`	histogram	Size of an XML element received from a component.
`component_xmpp_element_size_out_byte_size`	histogram	Size of an XML element sent to a component.
`component_tcp_data_in_byte_size`	counter	Amount of data received from a component via TCP channel.
`component_tcp_data_out_byte_size`	counter	Amount of data sent to a component via TCP channel.
`component_tls_data_in_byte_size`	counter	Amount of data received from a component via TLS channel.
`component_tls_data_out_byte_size`	counter	Amount of data sent to a component via TLS channel.

Metric name	Type	Description
`[global, c2s_xmpp_element_size_in, byte_size]`	histogram	Size of an XML element received from a client.
`[global, c2s_xmpp_element_size_out, byte_size]`	histogram	Size of an XML element sent to a client.
`[global, c2s_tcp_data_in, byte_size]`	spiral	Amount of data received from a client via TCP channel.
`[global, c2s_tcp_data_out, byte_size]`	spiral	Amount of data sent to a client via TCP channel.
`[global, c2s_tls_data_in, byte_size]`	spiral	Amount of data received from a client via TLS channel.
`[global, c2s_tls_data_out, byte_size]`	spiral	Amount of data sent to a client via TLS channel.
`[global, mod_bosh_data_received, byte_size]`	spiral	Amount of data received from a client via BOSH connection.
`[global, mod_bosh_data_sent, byte_size]`	spiral	Amount of data sent to a client via BOSH connection.
`[global, mod_websocket_data_received, byte_size]`	spiral	Amount of data received from a client via WebSocket connection.
`[global, mod_websocket_data_sent, byte_size]`	spiral	Amount of data sent to a client via WebSocket connection.
`[global, s2s_xmpp_element_size_in, byte_size]`	histogram	Size of an XML element received from another XMPP server.
`[global, s2s_xmpp_element_size_out, byte_size]`	histogram	Size of an XML element sent to another XMPP server.
`[global, s2s_tcp_data_in, byte_size]`	spiral	Amount of data received from another XMPP server via TCP channel.
`[global, s2s_tcp_data_out, byte_size]`	spiral	Amount of data sent to another XMPP server via TCP channel.
`[global, s2s_tls_data_in, byte_size]`	spiral	Amount of data received from another XMPP server via TLS channel.
`[global, s2s_tls_data_out, byte_size]`	spiral	Amount of data sent to another XMPP server via TLS channel.
`[global, component_xmpp_element_size_in, byte_size]`	histogram	Size of an XML element received from a component.
`[global, component_xmpp_element_size_out, byte_size]`	histogram	Size of an XML element sent to a component.
`[global, component_tcp_data_in, byte_size]`	spiral	Amount of data received from a component via TCP channel.
`[global, component_tcp_data_out, byte_size]`	spiral	Amount of data sent to a component via TCP channel.
`[global, component_tls_data_in, byte_size]`	spiral	Amount of data received from a component via TLS channel.
`[global, component_tls_data_out, byte_size]`	spiral	Amount of data sent to a component via TLS channel.

CETS system metrics¶

All of these metrics are updated periodically. The interval at which they are probed can be configured with the [instrumentation.probe_interval option].

PrometheusExometer

Metric name	Type	Description
`cets_info_available_nodes`	gauge	Available nodes (nodes that are connected to us and have the CETS disco process started).
`cets_info_unavailable_nodes`	gauge	Unavailable nodes (nodes that do not respond to our pings).
`cets_info_joined_nodes`	gauge	Joined nodes (nodes that have our local tables running).
`cets_info_discovered_nodes`	gauge	Discovered nodes (nodes that are extracted from the discovery backend).
`cets_info_remote_nodes_without_disco`	gauge	Nodes that have more tables registered than the local node.
`cets_info_remote_nodes_with_unknown_tables`	gauge	Nodes with unknown tables.
`cets_info_remote_unknown_tables`	gauge	Unknown remote tables.
`cets_info_remote_nodes_with_missing_tables`	gauge	Nodes that are available, but do not host some of our local tables.
`cets_info_remote_missing_tables`	gauge	Nodes that replicate at least one of our local tables to a different list of nodes.
`cets_info_conflict_nodes`	gauge	Nodes that replicate at least one of our local tables to a different list of nodes.
`cets_info_conflict_tables`	gauge	Tables that have conflicting replication destinations.
`cets_info_discovery_works`	gauge	Returns 1 if the last discovery attempt is successful (otherwise returns 0).

Metric name	Type	Description
`[global, cets_info, available_nodes]`	gauge	Available nodes (nodes that are connected to us and have the CETS disco process started).
`[global, cets_info, unavailable_nodes]`	gauge	Unavailable nodes (nodes that do not respond to our pings).
`[global, cets_info, joined_nodes]`	gauge	Joined nodes (nodes that have our local tables running).
`[global, cets_info, discovered_nodes]`	gauge	Discovered nodes (nodes that are extracted from the discovery backend).
`[global, cets_info, remote_nodes_without_disco]`	gauge	Nodes that have more tables registered than the local node.
`[global, cets_info, remote_nodes_with_unknown_tables]`	gauge	Nodes with unknown tables.
`[global, cets_info, remote_unknown_tables]`	gauge	Unknown remote tables.
`[global, cets_info, remote_nodes_with_missing_tables]`	gauge	Nodes that are available, but do not host some of our local tables.
`[global, cets_info, remote_missing_tables]`	gauge	Nodes that replicate at least one of our local tables to a different list of nodes.
`[global, cets_info, conflict_nodes]`	gauge	Nodes that replicate at least one of our local tables to a different list of nodes.
`[global, cets_info, conflict_tables]`	gauge	Tables that have conflicting replication destinations.
`[global, cets_info, discovery_works]`	gauge	Returns 1 if the last discovery attempt is successful (otherwise returns 0).

Pool metrics¶

For RDBMS global pool defined, an instance of these metrics are available. Prometheus metrics have a pool_tag label associated with these metrics. Since Exometer doesn't support labels, the tags are part of the metric names.

All of these metrics are updated periodically. The interval at which they are probed can be configured with the [instrumentation.probe_interval option].

PrometheusExometer

Name	Type	Description
`wpool_global_rdbms_stats_workers`	gauge	Number of workers in the pool
`wpool_global_rdbms_stats_recv_oct`	counter	Number of bytes received
`wpool_global_rdbms_stats_recv_cnt`	counter	Number of packets received
`wpool_global_rdbms_stats_recv_max`	gauge	Size of the largest packet, in bytes
`wpool_global_rdbms_stats_send_oct`	counter	Number of bytes sent
`wpool_global_rdbms_stats_send_max`	gauge	Size of the largest packet
`wpool_global_rdbms_stats_send_cnt`	counter	Number of packets sent
`wpool_global_rdbms_stats_send_pend`	counter	Number of bytes waiting to be sent

Name	Type	Description
`[global, wpool_global_rdbms_stats, PoolTag, workers]`	counter	Number of workers in the pool
`[global, wpool_global_rdbms_stats, PoolTag, recv_oct]`	spiral	Number of bytes received
`[global, wpool_global_rdbms_stats, PoolTag, recv_cnt]`	spiral	Number of packets received
`[global, wpool_global_rdbms_stats, PoolTag, recv_max]`	gauge	Size of the largest packet, in bytes
`[global, wpool_global_rdbms_stats, PoolTag, send_oct]`	spiral	Number of bytes sent
`[global, wpool_global_rdbms_stats, PoolTag, send_max]`	gauge	Size of the largest packet
`[global, wpool_global_rdbms_stats, PoolTag, send_cnt]`	spiral	Number of packets sent
`[global, wpool_global_rdbms_stats, PoolTag, send_pend]`	spiral	Number of bytes waiting to be sent

VM metrics¶

PrometheusExometer

Metric name	Type	Description
`system_memory_Metric`	gauge	Erlang memory statistics from `erlang:memory/0`. `Metric` specifies the memory type, e.g. `total`, `processes_used`, `atom_used`, `binary`, `ets` or `system`.
`system_info_Metric`	gauge	Erlang system statistics from `erlang:system_info/1`. `Metric` can be `port_count`, `port_limit`, `process_count`, `process_limit`, `ets_count` or `ets_limit`.

Metric name	Type	Description
`[global, system_memory, Metric]`	gauge	Erlang memory statistics from `erlang:memory/0`. `Metric` specifies the memory type, e.g. `total`, `processes_used`, `atom_used`, `binary`, `ets` or `system`.
`[global, system_info, Metric]`	gauge	Erlang system statistics from `erlang:system_info/1`. `Metric` can be `port_count`, `port_limit`, `process_count`, `process_limit`, `ets_count` or `ets_limit`.

Backend metrics¶

Some extension modules expose histograms with timings of calls made to their backends. Please check the documentation of modules that are enabled in your config file, in order to learn if they provide them.

Prometheus metrics have a host_type label associated with these metrics, as well as a function label describing the backend action. Since Exometer doesn't support labels, the host types and backend actions are part of the metric names.

PrometheusExometer

Metric name	Type	Description
`BackendModule_count`	counter	Number of calls (spiral metric), incremented for every call (even a failed one).
`BackendModule_time`	histogram	Times of successful operations.

Metric name	Type	Description
`[HostType, BackendModule, BackendAction, count]`	spiral	Number of calls (spiral metric), incremented for every call (even a failed one).
`[HostType, BackendModule, BackendAction, time]`	histogram	Times of successful operations.

Besides these, following authentication metrics are always available. Prometheus metrics have a host_type label associated with these metrics. Since Exometer doesn't support labels, the host types are part of the metric names.

PrometheusExometer

Metric name	Type	Description
`auth_register_user_count`	counter	A user registered successfully.
`auth_unregister_user_count`	counter	A user unregistered successfully.
`auth_authorize_count`	counter	A user tried to authorize.
`auth_authorize_time`	histogram	Time it took to authorize a user.
`auth_check_password_count`	counter	A password was checked.
`auth_check_password_time`	histogram	Time it took to check a password.
`auth_try_register_count`	counter	A user tried to register.
`auth_try_register_time`	histogram	Time it took to register a user.
`auth_does_user_exist_count`	counter	Whether a user exists was checked.
`auth_does_user_exist_time`	histogram	Time it took to check whether a user exists.

Metric name	Type	Description
`[HostType, auth_register_user, count]`	spiral	A user registered successfully.
`[HostType, auth_unregister_user, count]`	spiral	A user unregistered successfully.
`[HostType, auth_authorize, count]`	spiral	A user tried to authorize.
`[HostType, auth_authorize, time]`	histogram	Time it took to authorize a user.
`[HostType, auth_check_password, count]`	spiral	A password was checked.
`[HostType, auth_check_password, time]`	histogram	Time it took to check a password.
`[HostType, auth_try_register, count]`	spiral	A user tried to register.
`[HostType, auth_try_register, time]`	histogram	Time it took to register a user.
`[HostType, auth_does_user_exist, count]`	spiral	Whether a user exists was checked.
`[HostType, auth_does_user_exist, time]`	histogram	Time it took to check whether a user exists.

These are total times of respective operations. One operation usually requires only a single call to an auth backend but sometimes with e.g. 3 backends configured, the operation may fail for first 2 backends. In such case, these metrics will be updated with combined time of 2 failed and 1 successful request.