--- type: api title: Get follower stats description: Get cross-cluster replication follower stats. url: https://www.elastic.co/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v9/operation/operation-ccr-follow-stats resource: https://www.elastic.co/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v9/operation/operation-ccr-follow-stats products: - Elasticsearch --- # Get follower stats Availability: 6.5+ ## Paths - `GET` `/{index}/_ccr/stats` - [Api key auth](/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v9/authentication#apikeyauth) - [Basic auth](/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v9/authentication#basicauth) - [Bearer auth](/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v9/authentication#bearerauth) #### Path Parameters - `index` (union IndexName | [] IndexName) A comma-delimited list of index patterns. ## Description Get cross-cluster replication follower stats. The API returns shard-level stats about the "following tasks" associated with each shard for the specified indices. ## Required authorization * Cluster privileges: `monitor` [About cross-cluster replication](https://www.elastic.co/docs/deploy-manage/tools/cross-cluster-replication) ## Query String Parameters - `timeout` (string Duration · default: 30s) The period to wait for a response. If no response is received before the timeout expires, the request fails and returns an error. ## Response `application/json` - `indices` ([] FollowIndexStats) An array of follower index statistics. - `index` (string IndexName) The name of the follower index. - `shards` ([] ShardStats) An array of shard-level following task statistics. - `bytes_read` (number) The total of transferred bytes read from the leader. This is only an estimate and does not account for compression if enabled. - `failed_read_requests` (number) The number of failed reads. - `failed_write_requests` (number) The number of failed bulk write requests on the follower. - `fatal_exception` ({} ErrorCause) - `type` (string) The type of error - `reason` (union string) — nullable A human-readable explanation of the error, in English. One of: `string` - `stack_trace` (string) The server stack trace. Present only if the `error_trace=true` parameter was sent with the request. - `caused_by` ({} ErrorCause) — recursive Same fields as `fatal_exception` in `shards` - `root_cause` ([] ErrorCause) — recursive Same fields as `fatal_exception` in `shards` - `suppressed` ([] ErrorCause) — recursive Same fields as `fatal_exception` in `shards` - `follower_aliases_version` (number VersionNumber) The index aliases version the follower is synced up to. - `follower_global_checkpoint` (number) The current global checkpoint on the follower. The difference between the `leader_global_checkpoint` and the `follower_global_checkpoint` is an indication of how much the follower is lagging the leader. - `follower_index` (string) The name of the follower index. - `follower_mapping_version` (number VersionNumber) The mapping version the follower is synced up to. - `follower_max_seq_no` (number SequenceNumber) The current maximum sequence number on the follower. - `follower_settings_version` (number VersionNumber) The index settings version the follower is synced up to. - `last_requested_seq_no` (number SequenceNumber) The starting sequence number of the last batch of operations requested from the leader. - `leader_global_checkpoint` (number) The current global checkpoint on the leader known to the follower task. - `leader_index` (string) The name of the index in the leader cluster being followed. - `leader_max_seq_no` (number SequenceNumber) The current maximum sequence number on the leader known to the follower task. - `operations_read` (number) The total number of operations read from the leader. - `operations_written` (number) The number of operations written on the follower. - `outstanding_read_requests` (number) The number of active read requests from the follower. - `outstanding_write_requests` (number) The number of active bulk write requests on the follower. - `read_exceptions` ([] ReadException) An array of objects representing failed reads. - `exception` ({} ErrorCause) The exception that caused the read to fail. - `type` (string) The type of error - `reason` (union string) — nullable A human-readable explanation of the error, in English. One of: `string` - `stack_trace` (string) The server stack trace. Present only if the `error_trace=true` parameter was sent with the request. - `caused_by` ({} ErrorCause) — recursive Same fields as `exception` in `read_exceptions` - `root_cause` ([] ErrorCause) — recursive Same fields as `exception` in `read_exceptions` - `suppressed` ([] ErrorCause) — recursive Same fields as `exception` in `read_exceptions` - `from_seq_no` (number SequenceNumber) The starting sequence number of the batch requested from the leader. - `retries` (number) The number of times the batch has been retried. - `remote_cluster` (string) The remote cluster containing the leader index. - `shard_id` (number) The numerical shard ID, with values from 0 to one less than the number of replicas. - `successful_read_requests` (number) The number of successful fetches. - `successful_write_requests` (number) The number of bulk write requests run on the follower. - `time_since_last_read` (string Duration) - `time_since_last_read_millis` (DurationValueUnitMillis) The number of milliseconds since a read request was sent to the leader. When the follower is caught up to the leader, this number will increase up to the configured `read_poll_timeout` at which point another read request will be sent to the leader. - `total_read_remote_exec_time` (string Duration) - `total_read_remote_exec_time_millis` (DurationValueUnitMillis) The total time reads spent running on the remote cluster. - `total_read_time` (string Duration) - `total_read_time_millis` (DurationValueUnitMillis) The total time reads were outstanding, measured from the time a read was sent to the leader to the time a reply was returned to the follower. - `total_write_time` (string Duration) - `total_write_time_millis` (DurationValueUnitMillis) The total time spent writing on the follower. - `write_buffer_operation_count` (number) The number of write operations queued on the follower. - `write_buffer_size_in_bytes` (number | string ByteSize) The total number of bytes of operations currently queued for writing. ## Code Examples #### Console ```console GET /follower_index/_ccr/stats ``` #### JavaScript ```javascript const response = await client.ccr.followStats({ index: "follower_index", }); ``` #### Python ```python resp = client.ccr.follow_stats( index="follower_index", ) ``` #### curl ```curl curl -X GET "$ELASTICSEARCH_URL/follower_index/_ccr/stats" \ -H "Authorization: ApiKey $ELASTIC_API_KEY" ``` #### Java ```java client.ccr().followStats(f -> f .index("follower_index") ); ``` #### C# ```c# var response = await client.CrossClusterReplication.FollowStatsAsync(indices: new[] { "follower_index" }); ``` #### PHP ```php $resp = $client->ccr()->followStats([ "index" => "follower_index", ]); ``` #### Ruby ```ruby response = client.ccr.follow_stats( index: "follower_index" ) ``` ## Response Examples #### Follow index stats response example1 A successful response from `GET /follower_index/_ccr/stats`, which retrieves follower stats. ```json { "indices" : [ { "index" : "follower_index", "total_global_checkpoint_lag" : 256, "shards" : [ { "remote_cluster" : "remote_cluster", "leader_index" : "leader_index", "follower_index" : "follower_index", "shard_id" : 0, "leader_global_checkpoint" : 1024, "leader_max_seq_no" : 1536, "follower_global_checkpoint" : 768, "follower_max_seq_no" : 896, "last_requested_seq_no" : 897, "outstanding_read_requests" : 8, "outstanding_write_requests" : 2, "write_buffer_operation_count" : 64, "follower_mapping_version" : 4, "follower_settings_version" : 2, "follower_aliases_version" : 8, "total_read_time_millis" : 32768, "total_read_remote_exec_time_millis" : 16384, "successful_read_requests" : 32, "failed_read_requests" : 0, "operations_read" : 896, "bytes_read" : 32768, "total_write_time_millis" : 16384, "write_buffer_size_in_bytes" : 1536, "successful_write_requests" : 16, "failed_write_requests" : 0, "operations_written" : 832, "read_exceptions" : [ ], "time_since_last_read_millis" : 8 } ] } ] } ```