diff --git a/_api-reference/cat/cat-repositories.md b/_api-reference/cat/cat-repositories.md index 997b993cdd..906f29b2b4 100644 --- a/_api-reference/cat/cat-repositories.md +++ b/_api-reference/cat/cat-repositories.md @@ -3,7 +3,7 @@ layout: default title: CAT repositories parent: CAT API -nav_order: 55 +nav_order: 52 has_children: false --- diff --git a/_api-reference/cat/cat-segment-replication.md b/_api-reference/cat/cat-segment-replication.md new file mode 100644 index 0000000000..9a84b861eb --- /dev/null +++ b/_api-reference/cat/cat-segment-replication.md @@ -0,0 +1,166 @@ +--- +layout: default +title: CAT segment replication +parent: CAT API +nav_order: 53 +has_children: false +--- + +# CAT segment replication +Introduced 2.7 +{: .label .label-purple } + +The CAT segment replication operation returns information about active and last completed [segment replication]({{site.url}}{{site.baseurl}}/opensearch/segment-replication/index) events on each replica shard, including related shard-level metrics. These metrics provide information about how far behind the primary shard the replicas are lagging. + +Call the CAT Segment Replication API only on indexes with segment replication enabled. +{: .note} + +## Path and HTTP methods + +```json +GET /_cat/segment_replication +GET /_cat/segment_replication/ +``` + +## Path parameters + +The following table lists the available optional path parameter. + +Parameter | Type | Description +:--- | :--- | :--- +`index` | String | The name of the index, or a comma-separated list or wildcard expression of index names used to filter results. If this parameter is not provided, the response contains information about all indexes in the cluster. + +## Query parameters + +The CAT segment replication API operation supports the following optional query parameters. + +Parameter | Data type | Description +:--- |:---| :--- +`active_only` | Boolean | If `true`, the response only includes active segment replications. Defaults to `false`. +[`detailed`](#additional-detailed-response-metrics) | String | If `true`, the response includes additional metrics for each stage of a segment replication event. Defaults to `false`. +`shards` | String | A comma-separated list of shards to display. +`format` | String | A short version of the HTTP accept header. Valid values include `JSON` and `YAML`. +`h` | String | A comma-separated list of column names to display. +`help` | Boolean | If `true`, the response includes help information. Defaults to `false`. +`time` | Time value | [Units]({{site.url}}{{site.baseurl}}/opensearch/units) used to display time values. Defaults to `ms` (milliseconds). +`v` | Boolean | If `true`, the response includes column headings. Defaults to `false`. +`s` | String | Specifies to sort the results. For example, `s=shardId:desc` sorts by shardId in descending order. + +## Examples + +The following examples illustrate various segment replication responses. + +#### Example 1: No active segment replication events + +The following query requests segment replication metrics with column headings for all indexes: + +```json +GET /_cat/segment_replication?v=true +``` +{% include copy-curl.html %} + +The response contains the metrics for the preceding request: + +```bash +shardId target_node target_host checkpoints_behind bytes_behind current_lag last_completed_lag rejected_requests +[index-1][0] runTask-1 127.0.0.1 0 0b 0s 7ms 0 +``` + +#### Example 2: Shard ID specified + +The following query requests segment replication metrics with column headings for shards with the ID `0` from indexes `index1` and `index2`: + +```json +GET /_cat/segment_replication/index1,index2?v=true&shards=0 +``` +{% include copy-curl.html %} + +The response contains the metrics for the preceding request. The column headings correspond to the metric names: + +```bash +shardId target_node target_host checkpoints_behind bytes_behind current_lag last_completed_lag rejected_requests +[index-1][0] runTask-1 127.0.0.1 0 0b 0s 3ms 0 +[index-2][0] runTask-1 127.0.0.1 0 0b 0s 5ms 0 +``` + +#### Example 3: Detailed response + +The following query requests detailed segment replication metrics with column headings for all indexes: + +```json +GET /_cat/segment_replication?v=true&detailed=true +``` +{% include copy-curl.html %} + +The response contains additional metrics about the files and stages of a segment replication event: + +```bash +shardId target_node target_host checkpoints_behind bytes_behind current_lag last_completed_lag rejected_requests stage time files_fetched files_percent bytes_fetched bytes_percent start_time stop_time files files_total bytes bytes_total replicating_stage_time_taken get_checkpoint_info_stage_time_taken file_diff_stage_time_taken get_files_stage_time_taken finalize_replication_stage_time_taken +[index-1][0] runTask-1 127.0.0.1 0 0b 0s 3ms 0 done 10ms 6 100.0% 4753 100.0% 2023-03-16T13:46:16.802Z 2023-03-16T13:46:16.812Z 6 6 4.6kb 4.6kb 0s 2ms 0s 3ms 3ms +[index-2][0] runTask-1 127.0.0.1 0 0b 0s 5ms 0 done 7ms 3 100.0% 3664 100.0% 2023-03-16T13:53:33.466Z 2023-03-16T13:53:33.474Z 3 3 3.5kb 3.5kb 0s 1ms 0s 2ms 2ms +``` + +#### Example 4: Sorting the results + +The following query requests segment replication metrics with column headings for all indexes, sorted by shard ID in descending order: + +```json +GET /_cat/segment_replication?v&s=shardId:desc +``` +{% include copy-curl.html %} + +The response contains the sorted results: + +```bash +shardId target_node target_host checkpoints_behind bytes_behind current_lag last_completed_lag rejected_requests +[test6][1] runTask-2 127.0.0.1 0 0b 0s 5ms 0 +[test6][0] runTask-2 127.0.0.1 0 0b 0s 4ms 0 +``` + +#### Example 5: Using a metric alias + +In a request, you can either use a metric's full name or one of its aliases. The following query is the same as the preceding query, but it uses the alias `s` instead of `shardID` for sorting: + +```json +GET /_cat/segment_replication?v&s=s:desc +``` +{% include copy-curl.html %} + +## Response metrics + +The following table lists the response metrics that are returned for all requests. When referring to a metric in a query parameter, you can provide either the metric's full name or any of its aliases, as shown in the previous [example](#example-5-using-a-metric-alias). + +Metric | Alias | Description +:--- | :--- | :--- +`shardId` | `s` | The ID of a specific shard. +`target_host` | `thost` | The target host IP address. +`target_node` | `tnode` | The target node name. +`checkpoints_behind` | `cpb` | The number of checkpoints by which the replica shard is behind the primary shard. +`bytes_behind` | `bb` | The number of bytes by which the replica shard is behind the primary shard. +`current_lag` | `clag` | The time elapsed while waiting for a replica shard to catch up to the primary shard. +`last_completed_lag` | `lcl` | The time taken for a replica shard to catch up to the latest primary shard refresh. +`rejected_requests` | `rr` | The number of rejected requests for the replication group. + +### Additional detailed response metrics + +The following table lists the additional response fields returned if `detailed` is set to `true`. + +Metric | Alias | Description +:--- |:--- |:--- +`stage` | `st` | The current stage of a segment replication event. +`time` | `t`, `ti` | The amount of time a segment replication event took to complete, in milliseconds. +`files_fetched` | `ff` | The number of files fetched so far for a segment replication event. +`files_percent` | `fp` | The percentage of files fetched so far for a segment replication event. +`bytes_fetched` | `bf` | The number of bytes fetched so far for a segment replication event. +`bytes_percent` | `bp` | The number of bytes fetched so far for a segment replication event as a percentage. +`start_time` | `start` | The segment replication start time. +`stop_time` | `stop` | The segment replication stop time. +`files` | `f` | The number of files that needs to be fetched for a segment replication event. +`files_total` | `tf` | The total number of files that are part of this recovery, including both reused and recovered files. +`bytes` | `b` | The number of bytes that needs to be fetched for a segment replication event. +`bytes_total` | `tb` | The total number of bytes in the shard. +`replicating_stage_time_taken` | `rstt` | The amount of time the `replicating` stage of a segment replication event took to complete. +`get_checkpoint_info_stage_time_taken` | `gcistt` | The amount of time the `get checkpoint info` stage of a segment replication event took to complete. +`file_diff_stage_time_taken` | `fdstt` | The amount of time the `file diff` stage of a segment replication event took to complete. +`get_files_stage_time_taken` | `gfstt` | The amount of time the `get files` stage of a segment replication event took to complete. +`finalize_replication_stage_time_taken` | `frstt` | The amount of time the `finalize replication` stage of a segment replication event took to complete.