--- title: Metrics REST API (Static Page) description: Description of the Sync Gateway Metrics REST API, alternative representation as a static page pubDate: 2026-08-17T09:53:44.266Z antora: editUrl: https://github.com/couchbase/docs-sync-gateway/edit/release/3.0/modules/ROOT/pages/rest_api_metrics_static.adoc xref: xref:3.0@sync-gateway::rest_api_metrics_static.adoc[] --- [Consult the llms.txt file for a full list of contents](/llms.txt) [View original HTML](/sync-gateway/3.0/rest_api_metrics_static.html) # Metrics REST API (Static Page) > Description of the Sync Gateway Metrics REST API, alternative representation as a static page Related _REST API_ topics: [Public REST API (Static Page)](rest%5Fapi%5Fpublic%5Fstatic.md) | [Admin REST API (Static Page)](rest%5Fapi%5Fadmin%5Fstatic.md) ## [](#%5Fpaths)Paths This resources section groups together the available API operations under functional categories. * [Debugging/monitoring at runtime](#%5Fexpvar%5Fget) * [Debugging/monitoring runtime stats in Prometheus format](#%5Fmetrics%5Fget) ### [](#%5Fexpvar%5Fget)Debugging/monitoring at runtime GET /_expvar #### [](#description)Description The `Expvars` method returns Sync Gateways' numerous statistics, and other runtime variables, in JSON format. Making them readily available for debugging or performance monitoring purposes. **See** : [Sync Gateway Statistics Schema](stats-monitoring.html) for more details on the metrics collected and reported by Sync Gateway. _Sync Gateway Roles Required:_ – Sync Gateway Dev Ops – External Stats Reader #### [](#responses)Responses | HTTP Code | Description | Schema | | --------- | ---------------------- | ---------------------- | | **200** | OK - indicates success | [ExpVars](#%5Fexpvars) | #### [](#tags)Tags * Standard Output ### [](#%5Fmetrics%5Fget)Debugging/monitoring runtime stats in Prometheus format GET /_metrics #### [](#description-2)Description The `_metrics` method returns Sync Gateway's statistics and other runtime variables in **Prometheus** format. This makes for a convenient feed for your debugging or performance monitoring purposes. * For more details on the metrics collected and reported by Sync Gateway – see: [Sync Gateway Statistics Schema](stats-monitoring.html). * For more details on Monitoring Sync Gateway using the `_metrics` feed – see: our blog on [Monitoring and Visualization of Couchbase Sync Gateway with Prometheus and Grafana](https://blog.couchbase.com/monitoring-and-visualization-of-couchbase-sync-gateway-with-prometheus-and-grafana/) _Sync Gateway Roles Required:_ – Sync Gateway Dev Ops – External Stats Reader #### [](#responses-2)Responses | HTTP Code | Description | Schema | | --------- | ---------------------- | ---------------------- | | **200** | OK - indicates success | [Metrics](#%5Fmetrics) | #### [](#tags-2)Tags * Prometheus ## [](#%5Fdefinitions)Definitions ### [](#%5Fexpvars)ExpVars | Name | Description | Schema | | --------------------------------------- | ------------------------------------------------------------------------------- | ------------------------------------------------------------------- | | **cb** _optional_ | Variables reported by the Couchbase SDK (go\_couchbase package) | object | | **cmdline** _optional_ | Built-in variables from the Go runtime, lists the command-line arguments | object | | **mc** _optional_ | Variables reported by the low-level memcached API (gomemcached package) | object | | **memstats** _optional_ | Dumps a large amount of information about the memory heap and garbage collector | object | | **syncGateway\_changeCache** _optional_ | | [syncGateway\_changeCache](#%5Fexpvars%5Fsyncgateway%5Fchangecache) | | **syncGateway\_db** _optional_ | | [syncGateway\_db](#%5Fexpvars%5Fsyncgateway%5Fdb) | | **syncgateway** _optional_ | Monitoring stats | [syncgateway](#%5Fexpvars%5Fsyncgateway) | **syncGateway\_changeCache** | Name | Description | Schema | | ------------------------------- | -------------------------------------------------------------------- | ------ | | **lag-queue-0000ms** _optional_ | Histogram of delay from Tap feed till doc is posted to changes feed | object | | **lag-tap-0000ms** _optional_ | Histogram of delay from doc save till it shows up in Tap feed | object | | **lag-total-0000ms** _optional_ | Histogram of total delay from doc save till posted to changes feed | object | | **maxPending** _optional_ | Max number of sequences waiting on a missing earlier sequence number | object | | **outOfOrder** _optional_ | Number of out-of-order sequences posted | object | | **view\_queries** _optional_ | Number of queries to channels view | object | **syncGateway\_db** | Name | Description | Schema | | ------------------------------------------ | ----------------------------------------------------------------------------------------------------- | ------ | | **channelChangesFeeds** _optional_ | Number of calls to db.changesFeed, i.e. generating a changes feed for a single channel. | object | | **channelLogAdds** _optional_ | Number of entries added to channel logs | object | | **channelLogAppends** _optional_ | Number of times entries were written to channel logs using an APPEND operation | object | | **channelLogCacheHits** _optional_ | Number of requests for channel-logs that were fulfilled from the in-memory cache | object | | **channelLogRewriteCollisions** _optional_ | Number of collisions while attempting to rewrite channel logs using SET | object | | **channelLogRewrites** _optional_ | Number of times entries were written to channel logs using a SET operation (rewriting the entire log) | object | | **document\_gets** _optional_ | Number of times a document was read from the database | object | | **revisionCache\_adds** _optional_ | Number of revisions added to the revision cache | object | | **revisionCache\_hits** _optional_ | Number of times a revision-cache lookup succeeded | object | | **revisionCache\_misses** _optional_ | Number of times a revision-cache lookup failed | object | | **revs\_added** _optional_ | Number of revisions added to the database (including deletions) | object | | **sequence\_gets** _optional_ | Number of times the database's lastSequence was read | object | | **sequence\_reserves** _optional_ | Number of times the database's lastSequence was incremented | object | **syncgateway** | Name | Description | Schema | | ------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------- | | **global** _optional_ | Global Sync Gateway stats | [global](#%5Fexpvars%5Fglobal) | | **per\_db** _optional_ | This array contains stats for all databases declared in the config file – see the [Sync Gateway Statistics Schema](stats-monitoring.html) for more details on the metrics collected and reported by Sync Gateway. The statistics for each {$db\_name} database are grouped into: \* cache related statistics \* cbl\_replication\_push \* cbl\_replication\_pull \* database\_related\_statistics \* delta\_sync \* gsi\_views \* security\_related\_statistics \* shared\_bucket\_import \* per\_replication statistics for each replication\_id | < [per\_db](#%5Fexpvars%5Fper%5Fdb) \> array | | **per\_replication** _optional_ | An array of stats for each replication declared in the config file **Deprecated @ 2.8**: used only by inter-sync-gateway replications version 1. | < [per\_replication](#%5Fexpvars%5Fper%5Freplication) \> array | **global** | Name | Description | Schema | | ------------------------------------ | -------------------------- | ---------------------------------------------------------------------- | | **resource\_utilization** _optional_ | Resource utilization stats | [resource\_utilization](#%5Fexpvars%5Fglobal%5Fresource%5Futilization) | **resource\_utilization** | Name | Schema | | ------------------------------------------------- | ------- | | **admin\_net\_bytes\_recv** _optional_ | integer | | **admin\_net\_bytes\_sent** _optional_ | integer | | **error\_count** _optional_ | integer | | **go\_memstats\_heapalloc** _optional_ | integer | | **go\_memstats\_heapidle** _optional_ | integer | | **go\_memstats\_heapinuse** _optional_ | integer | | **go\_memstats\_heapreleased** _optional_ | integer | | **go\_memstats\_pausetotalns** _optional_ | integer | | **go\_memstats\_stackinuse** _optional_ | integer | | **go\_memstats\_stacksys** _optional_ | integer | | **go\_memstats\_sys** _optional_ | integer | | **goroutines\_high\_watermark** _optional_ | integer | | **num\_goroutines** _optional_ | integer | | **process\_cpu\_percent\_utilization** _optional_ | integer | | **process\_memory\_resident** _optional_ | integer | | **pub\_net\_bytes\_recv** _optional_ | integer | | **pub\_net\_bytes\_sent** _optional_ | integer | | **system\_memory\_total** _optional_ | integer | | **warn\_count** _optional_ | integer | **per\_db** | Name | Schema | | ------------------------------- | ---------------- | | **cache** _optional_ | object | | **database** _optional_ | object | | **per\_replication** _optional_ | < object > array | | **security** _optional_ | object | **per\_replication** | Name | Schema | | ------------------------------- | ---------------------------------------------------------------------- | | **$replication\_id** _optional_ | [$replication\_id](#%5Fexpvars%5Fper%5Freplication%5Freplication%5Fid) | **$replication\_id** | Name | Description | Schema | | ------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- | | **sgr\_active** _optional_ | Whether the replication is active at this time. **Deprecated @ 2.8**: used only by inter-sync-gateway replications version 1. | boolean | | **sgr\_docs\_checked\_sent** _optional_ | The total number of documents checked for changes since replication started. This represents the number of potential change notifications pushed by Sync Gateway. **Constraints**This is not necessarily the number of documents pushed, as a given target might already have the change. Used by versions 1 and 2. | integer | | **sgr\_num\_attachment\_bytes\_transferred** _optional_ | The total number of attachment bytes transferred since replication started. **Deprecated @ 2.8**: used only by inter-sync-gateway replications version 1. | integer | | **sgr\_num\_attachments\_transferred** _optional_ | The total number of attachments transferred since replication started. **Deprecated @ 2.8**: used only by inter-sync-gateway replications version 1. | integer | | **sgr\_num\_docs\_failed\_to\_push** _optional_ | The total number of documents that failed to be pushed since replication started. Used by versions 1 and 2. | integer | | **sgr\_num\_docs\_pushed** _optional_ | The total number of documents that were pushed since replication started. Used by versions 1 and 2. | integer | ### [](#%5Fmetrics)Metrics The Prometheus output is expected to by consumed only by a Prometheus server. For that reason its format is irrelevant, and a brief extract is show here for completeness and information only. * For more details on the metrics collected and reported by Sync Gateway – see: [Sync Gateway Statistics Schema](stats-monitoring.html). * For more details on Monitoring Sync Gateway using the `_metrics` feed – see: our blog on [Monitoring and Visualization of Couchbase Sync Gateway with Prometheus and Grafana](https://blog.couchbase.com/monitoring-and-visualization-of-couchbase-sync-gateway-with-prometheus-and-grafana/) ... # HELP go_gc_duration_seconds A summary of the pause duration of garbage collection cycles. # TYPE go_gc_duration_seconds summary go_gc_duration_seconds{quantile="0"} 0.0001155 go_gc_duration_seconds{quantile="0.25"} 0.0001254 go_gc_duration_seconds{quantile="0.5"} 0.0001597 go_gc_duration_seconds{quantile="0.75"} 0.0001806 go_gc_duration_seconds{quantile="1"} 0.0049731 go_gc_duration_seconds_sum 0.006334 go_gc_duration_seconds_count 9 # HELP go_goroutines Number of goroutines that currently exist. # TYPE go_goroutines gauge go_goroutines 205 ... _Type_ : object --- ##### ## [](#related-content)Related Content ###### [](#-2) API Topics * [Public REST API](rest-api.md) * [Admin REST API](rest-api-admin.md) * [Metrics REST API](rest-api-metrics.md) ###### [](#-3) Reference * [Bootstrap](configuration-schema-bootstrap.md) * [Database](configuration-schema-database.md) * [Database Security](configuration-schema-db-security.md) * [Access Control](configuration-schema-access-control.md) * [Import Filter](configuration-schema-import-filter.md) * [Inter-Sync Gateway Replication](configuration-schema-isgr.md) * [Legacy Pre-3.0 Configuration](configuration-properties-legacy.md) ###### [](#-4) Community [Mobile Forum](https://forums.couchbase.com/c/mobile/14) | [Blog](https://blog.couchbase.com/) | [Blog (Mobile)](https://blog.couchbase.com/category/couchbase-mobile/?ref=blog-menu) | [Tutorials](https://docs.couchbase.com/tutorials/)