VOLUME.STATS REPLICATION

Returns replication state for a specific standby member on a named volume.

Syntax

VOLUME.STATS <volume-name> REPLICATION <standby-id>

Arguments

Argument	Type	Description
volume-name	string	Name of the volume, in <kind>-shard-<id> format (e.g. bucket-shard-0)
standby-id	string	Member ID of the standby to inspect

Return Value

RESP3 map with the following fields:

Field	Type	Description
stage	string	Current replication stage (e.g. SEGMENT_REPLICATION, CHANGE_DATA_CAPTURE), or empty string if not started
status	string	Replication status (e.g. WAITING, RUNNING, FAILED), or empty string if unknown
error_message	string	Error description if replication has failed, or empty string
cursor_segment_id	integer	Segment ID the replication cursor is currently on (0 if not started)
cursor_position	integer	Byte position within the cursor segment (0 if not started)
cdc_sequence_number	integer	Change data capture sequence number (0 if not in CDC stage)
cdc_position	integer	Position within the current CDC sequence (0 if not in CDC stage)

Behavior

Reads the replication status of the given standby for the named volume.

Fields default to empty strings (for stage, status, error_message) or zero (for numeric fields) when replication has not started or the standby subspace has not been initialized.

This command requires exactly 3 arguments total (volume name, subcommand, standby ID).

This command is available on the management port (default 3320).

Errors

Argument errors:

Error Code	Error message	Cause
ERR	invalid number of arguments	-
ERR	invalid volume name: <name>	The name does not match the <kind>-shard-<id> format.
ERR	Invalid memberId: <id>	The value is neither a 40-character member ID nor a 4-character prefix.

Examples

Replication in segment replication stage:

127.0.0.1:3320> VOLUME.STATS bucket-shard-0 REPLICATION standby-member-1
1# "stage" => "SEGMENT_REPLICATION"
2# "status" => "RUNNING"
3# "error_message" => ""
4# "cursor_segment_id" => (integer) 2
5# "cursor_position" => (integer) 51200
6# "cdc_sequence_number" => (integer) 0
7# "cdc_position" => (integer) 0

Replication in change data capture stage:

127.0.0.1:3320> VOLUME.STATS bucket-shard-0 REPLICATION standby-member-1
1# "stage" => "CHANGE_DATA_CAPTURE"
2# "status" => "RUNNING"
3# "error_message" => ""
4# "cursor_segment_id" => (integer) 3
5# "cursor_position" => (integer) 0
6# "cdc_sequence_number" => (integer) 42
7# "cdc_position" => (integer) 1024

Replication not yet started:

127.0.0.1:3320> VOLUME.STATS bucket-shard-0 REPLICATION standby-member-1
1# "stage" => ""
2# "status" => "WAITING"
3# "error_message" => ""
4# "cursor_segment_id" => (integer) 0
5# "cursor_position" => (integer) 0
6# "cdc_sequence_number" => (integer) 0
7# "cdc_position" => (integer) 0

Failed replication:

127.0.0.1:3320> VOLUME.STATS bucket-shard-0 REPLICATION standby-member-1
1# "stage" => "SEGMENT_REPLICATION"
2# "status" => "FAILED"
3# "error_message" => "Connection refused"
4# "cursor_segment_id" => (integer) 1
5# "cursor_position" => (integer) 4096
6# "cdc_sequence_number" => (integer) 0
7# "cdc_position" => (integer) 0