+ +

How to monitor Synapse metrics using Prometheus

+
Install Prometheus:
+
Follow instructions at +http://prometheus.io/docs/introduction/install/
+
+
Enable Synapse metrics:
+
There are two methods of enabling metrics in Synapse.
+
The first serves the metrics as a part of the usual web server and +can be enabled by adding the "metrics" resource to the existing +listener as such:
+
```
  resources:
+    - names:
+      - client
+      - metrics
+
```
+
This provides a simple way of adding metrics to your Synapse +installation, and serves under /_synapse/metrics. If you do not +wish your metrics be publicly exposed, you will need to either +filter it out at your load balancer, or use the second method.
+
The second method runs the metrics server on a different port, in a +different thread to Synapse. This can make it more resilient to +heavy load meaning metrics cannot be retrieved, and can be exposed +to just internal networks easier. The served metrics are available +over HTTP only, and will be available at /_synapse/metrics.
+
Add a new listener to homeserver.yaml:
+
```
  listeners:
+    - type: metrics
+      port: 9000
+      bind_addresses:
+        - '0.0.0.0'
+
```
+
For both options, you will need to ensure that enable_metrics is +set to True.
+
+
Restart Synapse.
+
+
Add a Prometheus target for Synapse.
+
It needs to set the metrics_path to a non-default value (under +scrape_configs):
+
```
  - job_name: "synapse"
+    scrape_interval: 15s
+    metrics_path: "/_synapse/metrics"
+    static_configs:
+      - targets: ["my.server.here:port"]
+
```
+
where my.server.here is the IP address of Synapse, and port is +the listener port configured with the metrics resource.
+
If your prometheus is older than 1.5.2, you will need to replace +static_configs in the above with target_groups.
+
+
Restart Prometheus.
+
+
Consider using the grafana dashboard +and required recording rules
+

Monitoring workers

To monitor a Synapse installation using workers, +every worker needs to be monitored independently, in addition to +the main homeserver process. This is because workers don't send +their metrics to the main homeserver process, but expose them +directly (if they are configured to do so).

To allow collecting metrics from a worker, you need to add a +metrics listener to its configuration, by adding the following +under worker_listeners:

  - type: metrics
+    bind_address: ''
+    port: 9101
+

The bind_address and port parameters should be set so that +the resulting listener can be reached by prometheus, and they +don't clash with an existing worker. +With this example, the worker's metrics would then be available +on http://127.0.0.1:9101.

Example Prometheus target for Synapse with workers:

  - job_name: "synapse"
+    scrape_interval: 15s
+    metrics_path: "/_synapse/metrics"
+    static_configs:
+      - targets: ["my.server.here:port"]
+        labels:
+          instance: "my.server"
+          job: "master"
+          index: 1
+      - targets: ["my.workerserver.here:port"]
+        labels:
+          instance: "my.server"
+          job: "generic_worker"
+          index: 1
+      - targets: ["my.workerserver.here:port"]
+        labels:
+          instance: "my.server"
+          job: "generic_worker"
+          index: 2
+      - targets: ["my.workerserver.here:port"]
+        labels:
+          instance: "my.server"
+          job: "media_repository"
+          index: 1
+

Labels (instance, job, index) can be defined as anything. +The labels are used to group graphs in grafana.

Renaming of metrics & deprecation of old names in 1.2

Synapse 1.2 updates the Prometheus metrics to match the naming +convention of the upstream prometheus_client. The old names are +considered deprecated and will be removed in a future version of +Synapse.

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Removal of deprecated metrics & time based counters becoming histograms in 0.31.0

The duplicated metrics deprecated in Synapse 0.27.0 have been removed.

All time duration-based metrics have been changed to be seconds. This +affects:

+ + + + + + +

msec -> sec metrics
python_gc_time
python_twisted_reactor_tick_time
synapse_storage_query_time
synapse_storage_schedule_time
synapse_storage_transaction_time

Several metrics have been changed to be histograms, which sort entries +into buckets and allow better analysis. The following metrics are now +histograms:

+ + + + + + + + +

Altered metrics
python_gc_time
python_twisted_reactor_pending_calls
python_twisted_reactor_tick_time
synapse_http_server_response_time_seconds
synapse_storage_query_time
synapse_storage_schedule_time
synapse_storage_transaction_time

Block and response metrics renamed for 0.27.0

Synapse 0.27.0 begins the process of rationalising the duplicate +*:count metrics reported for the resource tracking for code blocks and +HTTP requests.

At the same time, the corresponding *:total metrics are being renamed, +as the :total suffix no longer makes sense in the absence of a +corresponding :count metric.

To enable a graceful migration path, this release just adds new names +for the metrics being renamed. A future release will remove the old +ones.

The following table shows the new metrics, and the old metrics which +they are replacing.

+ + + + + + + + + + + + + + + + + + + + + + +

New name	Old name
synapse_util_metrics_block_count	synapse_util_metrics_block_timer:count
synapse_util_metrics_block_count	synapse_util_metrics_block_ru_utime:count
synapse_util_metrics_block_count	synapse_util_metrics_block_ru_stime:count
synapse_util_metrics_block_count	synapse_util_metrics_block_db_txn_count:count
synapse_util_metrics_block_count	synapse_util_metrics_block_db_txn_duration:count
synapse_util_metrics_block_time_seconds	synapse_util_metrics_block_timer:total
synapse_util_metrics_block_ru_utime_seconds	synapse_util_metrics_block_ru_utime:total
synapse_util_metrics_block_ru_stime_seconds	synapse_util_metrics_block_ru_stime:total
synapse_util_metrics_block_db_txn_count	synapse_util_metrics_block_db_txn_count:total
synapse_util_metrics_block_db_txn_duration_seconds	synapse_util_metrics_block_db_txn_duration:total
synapse_http_server_response_count	synapse_http_server_requests
synapse_http_server_response_count	synapse_http_server_response_time:count
synapse_http_server_response_count	synapse_http_server_response_ru_utime:count
synapse_http_server_response_count	synapse_http_server_response_ru_stime:count
synapse_http_server_response_count	synapse_http_server_response_db_txn_count:count
synapse_http_server_response_count	synapse_http_server_response_db_txn_duration:count
synapse_http_server_response_time_seconds	synapse_http_server_response_time:total
synapse_http_server_response_ru_utime_seconds	synapse_http_server_response_ru_utime:total
synapse_http_server_response_ru_stime_seconds	synapse_http_server_response_ru_stime:total
synapse_http_server_response_db_txn_count	synapse_http_server_response_db_txn_count:total
synapse_http_server_response_db_txn_duration_seconds	synapse_http_server_response_db_txn_duration:total

Standard Metric Names

As of synapse version 0.18.2, the format of the process-wide metrics has +been changed to fit prometheus standard naming conventions. Additionally +the units have been changed to seconds, from miliseconds.

+ + + + +

New name	Old name
process_cpu_user_seconds_total	process_resource_utime / 1000
process_cpu_system_seconds_total	process_resource_stime / 1000
process_open_fds (no 'type' label)	process_fds

The python-specific counts of garbage collector performance have been +renamed.

+ + + + +

New name	Old name
python_gc_time	reactor_gc_time
python_gc_unreachable_total	reactor_gc_unreachable
python_gc_counts	reactor_gc_counts

The twisted-specific reactor metrics have been renamed.

+ + + +

New name	Old name
python_twisted_reactor_pending_calls	reactor_pending_calls
python_twisted_reactor_tick_time	reactor_tick_time

+ +

New Name	Old Name
python_gc_objects_collected_total	python_gc_objects_collected
python_gc_objects_uncollectable_total	python_gc_objects_uncollectable
python_gc_collections_total	python_gc_collections
process_cpu_seconds_total	process_cpu_seconds
synapse_federation_client_sent_transactions_total	synapse_federation_client_sent_transactions
synapse_federation_client_events_processed_total	synapse_federation_client_events_processed
synapse_event_processing_loop_count_total	synapse_event_processing_loop_count
synapse_event_processing_loop_room_count_total	synapse_event_processing_loop_room_count
synapse_util_metrics_block_count_total	synapse_util_metrics_block_count
synapse_util_metrics_block_time_seconds_total	synapse_util_metrics_block_time_seconds
synapse_util_metrics_block_ru_utime_seconds_total	synapse_util_metrics_block_ru_utime_seconds
synapse_util_metrics_block_ru_stime_seconds_total	synapse_util_metrics_block_ru_stime_seconds
synapse_util_metrics_block_db_txn_count_total	synapse_util_metrics_block_db_txn_count
synapse_util_metrics_block_db_txn_duration_seconds_total	synapse_util_metrics_block_db_txn_duration_seconds
synapse_util_metrics_block_db_sched_duration_seconds_total	synapse_util_metrics_block_db_sched_duration_seconds
synapse_background_process_start_count_total	synapse_background_process_start_count
synapse_background_process_ru_utime_seconds_total	synapse_background_process_ru_utime_seconds
synapse_background_process_ru_stime_seconds_total	synapse_background_process_ru_stime_seconds
synapse_background_process_db_txn_count_total	synapse_background_process_db_txn_count
synapse_background_process_db_txn_duration_seconds_total	synapse_background_process_db_txn_duration_seconds
synapse_background_process_db_sched_duration_seconds_total	synapse_background_process_db_sched_duration_seconds
synapse_storage_events_persisted_events_total	synapse_storage_events_persisted_events
synapse_storage_events_persisted_events_sep_total	synapse_storage_events_persisted_events_sep
synapse_storage_events_state_delta_total	synapse_storage_events_state_delta
synapse_storage_events_state_delta_single_event_total	synapse_storage_events_state_delta_single_event
synapse_storage_events_state_delta_reuse_delta_total	synapse_storage_events_state_delta_reuse_delta
synapse_federation_server_received_pdus_total	synapse_federation_server_received_pdus
synapse_federation_server_received_edus_total	synapse_federation_server_received_edus
synapse_handler_presence_notified_presence_total	synapse_handler_presence_notified_presence
synapse_handler_presence_federation_presence_out_total	synapse_handler_presence_federation_presence_out
synapse_handler_presence_presence_updates_total	synapse_handler_presence_presence_updates
synapse_handler_presence_timers_fired_total	synapse_handler_presence_timers_fired
synapse_handler_presence_federation_presence_total	synapse_handler_presence_federation_presence
synapse_handler_presence_bump_active_time_total	synapse_handler_presence_bump_active_time
synapse_federation_client_sent_edus_total	synapse_federation_client_sent_edus
synapse_federation_client_sent_pdu_destinations_count_total	synapse_federation_client_sent_pdu_destinations:count
synapse_federation_client_sent_pdu_destinations_total	synapse_federation_client_sent_pdu_destinations:total
synapse_handlers_appservice_events_processed_total	synapse_handlers_appservice_events_processed
synapse_notifier_notified_events_total	synapse_notifier_notified_events
synapse_push_bulk_push_rule_evaluator_push_rules_invalidation_counter_total	synapse_push_bulk_push_rule_evaluator_push_rules_invalidation_counter