[role="xpack"] [testenv="platinum"] [[ccr-get-follow-stats]] === Get Follower Stats API ++++ Get Follower Stats ++++ beta[] Get follower stats. ==== Description This API gets follower stats. This API will return shard-level stats about the following tasks associated with each shard for the specified indices. ==== Request ////////////////////////// [source,js] -------------------------------------------------- PUT /follower_index/_ccr/follow { "remote_cluster" : "remote_cluster", "leader_index" : "leader_index" } -------------------------------------------------- // CONSOLE // TESTSETUP // TEST[setup:remote_cluster_and_leader_index] [source,js] -------------------------------------------------- POST /follower_index/_ccr/pause_follow -------------------------------------------------- // CONSOLE // TEARDOWN ////////////////////////// [source,js] -------------------------------------------------- GET //_ccr/stats -------------------------------------------------- // CONSOLE // TEST[s//follower_index/] ==== Path Parmeters `index` :: (string) a comma-delimited list of index patterns ==== Results This API returns the following information: `indices`:: (array) an array of follower index statistics The `indices` array consists of objects containing two fields: `indices[].index`:: (string) the name of the follower index `indices[].shards`:: (array) an array of shard-level following task statistics The `shards` array consists of objects containing the following fields: `indices[].shards[].remote_cluster`:: (string) the > containing the leader index `indices[].shards[].leader_index`:: (string) the name of the index in the leader cluster being followed `indices[].shards[].follower_index`:: (string) the name of the follower index `indices[].shards[].shard_id`:: (integer) the numerical shard ID, with values from 0 to one less than the number of replicas `indices[].shards[].leader_global_checkpoint`:: (long) the current global checkpoint on the leader known to the follower task `indices[].shards[].leader_max_seq_no`:: (long) the current maximum sequence number on the leader known to the follower task `indices[].shards[].follower_global_checkpoint`:: (long) 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 `indices[].shards[].follower_max_seq_no`:: (long) the current maximum sequence number on the follower `indices[].shards[].last_requested_seq_no`:: (long) the starting sequence number of the last batch of operations requested from the leader `indices[].shards[].outstanding_read_requests`:: (integer) the number of active read requests from the follower `indices[].shards[].outstanding_write_requests`:: (integer) the number of active bulk write requests on the follower `indices[].shards[].write_buffer_operation_count`:: (integer) the number of write operations queued on the follower `indices[].shards[].follower_mapping_version`:: (long) the mapping version the follower is synced up to `indices[].shards[].follower_settings_version`:: (long) the index settings version the follower is synced up to `indices[].shards[].total_read_time_millis`:: (long) 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 `indices[].shards[].total_read_remote_exec_time_millis`:: (long) the total time reads spent executing on the remote cluster `indices[].shards[].successful_read_requests`:: (long) the number of successful fetches `indices[].shards[].failed_read_requests`:: (long) the number of failed reads `indices[].shards[].operations_read`:: (long) the total number of operations read from the leader `indices[].shards[].bytes_read`:: (long) the total of transferred bytes read from the leader (note this is only an estimate, and does not account for compression if enabled) `indices[].shards[].total_write_time_millis`:: (long) the total time spent writing on the follower `indices[].shards[].write_buffer_size_in_bytes`:: (long) the total number of bytes of operations currently queued for writing `indices[].shards[].successful_write_requests`:: (long) the number of bulk write requests executed on the follower `indices[].shards[].failed_write_requests`:: (long) the number of failed bulk write requests executed on the follower `indices[].shards[].operations_written`:: (long) the number of operations written on the follower `indices[].shards[].read_exceptions`:: (array) an array of objects representing failed reads The `read_exceptions` array consists of objects containing the following fields: `indices[].shards[].read_exceptions[].from_seq_no`:: (long) the starting sequence number of the batch requested from the leader `indices[].shards[].read_exceptions[].retries`:: (integer) the number of times the batch has been retried `indices[].shards[].read_exceptions[].exception`:: (object) represents the exception that caused the read to fail Continuing with the fields from `shards`: `indices[].shards[].time_since_last_read_millis`:: (long) the number of milliseconds since a read request was sent to the leader; note that 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 `indices[].fatal_exception`:: (object) an object representing a fatal exception that cancelled the following task; in this situation, the following task must be resumed manually with the <> ==== Authorization If the {es} {security-features} are enabled, you must have `monitor` cluster privileges on the cluster that contains the follower index. For more information, see {stack-ov}/security-privileges.html[Security privileges]. ==== Example This example retrieves follower stats: [source,js] -------------------------------------------------- GET /follower_index/_ccr/stats -------------------------------------------------- // CONSOLE The API returns the following results: [source,js] -------------------------------------------------- { "indices" : [ { "index" : "follower_index", "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, "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 } ] } ] } -------------------------------------------------- // TESTRESPONSE[s/"leader_global_checkpoint" : 1024/"leader_global_checkpoint" : $body.indices.0.shards.0.leader_global_checkpoint/] // TESTRESPONSE[s/"leader_max_seq_no" : 1536/"leader_max_seq_no" : $body.indices.0.shards.0.leader_max_seq_no/] // TESTRESPONSE[s/"follower_global_checkpoint" : 768/"follower_global_checkpoint" : $body.indices.0.shards.0.follower_global_checkpoint/] // TESTRESPONSE[s/"follower_max_seq_no" : 896/"follower_max_seq_no" : $body.indices.0.shards.0.follower_max_seq_no/] // TESTRESPONSE[s/"last_requested_seq_no" : 897/"last_requested_seq_no" : $body.indices.0.shards.0.last_requested_seq_no/] // TESTRESPONSE[s/"outstanding_read_requests" : 8/"outstanding_read_requests" : $body.indices.0.shards.0.outstanding_read_requests/] // TESTRESPONSE[s/"outstanding_write_requests" : 2/"outstanding_write_requests" : $body.indices.0.shards.0.outstanding_write_requests/] // TESTRESPONSE[s/"write_buffer_operation_count" : 64/"write_buffer_operation_count" : $body.indices.0.shards.0.write_buffer_operation_count/] // TESTRESPONSE[s/"follower_mapping_version" : 4/"follower_mapping_version" : $body.indices.0.shards.0.follower_mapping_version/] // TESTRESPONSE[s/"follower_settings_version" : 2/"follower_settings_version" : $body.indices.0.shards.0.follower_settings_version/] // TESTRESPONSE[s/"total_read_time_millis" : 32768/"total_read_time_millis" : $body.indices.0.shards.0.total_read_time_millis/] // TESTRESPONSE[s/"total_read_remote_exec_time_millis" : 16384/"total_read_remote_exec_time_millis" : $body.indices.0.shards.0.total_read_remote_exec_time_millis/] // TESTRESPONSE[s/"successful_read_requests" : 32/"successful_read_requests" : $body.indices.0.shards.0.successful_read_requests/] // TESTRESPONSE[s/"failed_read_requests" : 0/"failed_read_requests" : $body.indices.0.shards.0.failed_read_requests/] // TESTRESPONSE[s/"operations_read" : 896/"operations_read" : $body.indices.0.shards.0.operations_read/] // TESTRESPONSE[s/"bytes_read" : 32768/"bytes_read" : $body.indices.0.shards.0.bytes_read/] // TESTRESPONSE[s/"total_write_time_millis" : 16384/"total_write_time_millis" : $body.indices.0.shards.0.total_write_time_millis/] // TESTRESPONSE[s/"write_buffer_size_in_bytes" : 1536/"write_buffer_size_in_bytes" : $body.indices.0.shards.0.write_buffer_size_in_bytes/] // TESTRESPONSE[s/"successful_write_requests" : 16/"successful_write_requests" : $body.indices.0.shards.0.successful_write_requests/] // TESTRESPONSE[s/"failed_write_requests" : 0/"failed_write_requests" : $body.indices.0.shards.0.failed_write_requests/] // TESTRESPONSE[s/"operations_written" : 832/"operations_written" : $body.indices.0.shards.0.operations_written/] // TESTRESPONSE[s/"time_since_last_read_millis" : 8/"time_since_last_read_millis" : $body.indices.0.shards.0.time_since_last_read_millis/]