system.replication_queue
Description
Contains information about tasks from replication queues stored in ClickHouse Keeper, or ZooKeeper, for tables in the ReplicatedMergeTree family.
Columns
database(String) — Name of the database.table(String) — Name of the table.replica_name(String) — Replica name in ClickHouse Keeper. Different replicas of the same table have different names.position(UInt32) — Position of the task in the queue.node_name(String) — Node name in ClickHouse Keeper.type(String) — Type of the task in the queue, one of: • GET_PART — Get the part from another replica, • ATTACH_PART — Attach the part, possibly from our own replica (if found in the detached folder). You may think of it as a GET_PART with some optimizations as they're nearly identical, • MERGE_PARTS — Merge the parts, • DROP_RANGE — Delete the parts in the specified partition in the specified number range. • CLEAR_COLUMN — NOTE: Deprecated. Drop specific column from specified partition. • CLEAR_INDEX — NOTE: Deprecated. Drop specific index from specified partition. • REPLACE_RANGE — Drop a certain range of parts and replace them with new ones. • MUTATE_PART — Apply one or several mutations to the part. • ALTER_METADATA — Apply alter modification according to global /metadata and /columns paths.create_time(DateTime) — Date and time when the task was submitted for execution.required_quorum(UInt32) — The number of replicas waiting for the task to complete with confirmation of completion. This column is only relevant for the GET_PARTS task.source_replica(String) — Name of the source replica.new_part_name(String) — Name of the new part.parts_to_merge(Array(String)) — Names of parts to merge or update.is_detach(UInt8) — The flag indicates whether the DETACH_PARTS task is in the queue.is_currently_executing(UInt8) — The flag indicates whether a specific task is being performed right now.num_tries(UInt32) — The number of failed attempts to complete the task.last_exception(String) — Text message about the last error that occurred (if any).last_exception_time(DateTime) — Date and time when the last error occurred.last_attempt_time(DateTime) — Date and time when the task was last attempted.num_postponed(UInt32) — The number of times the action was postponed.postpone_reason(String) — The reason why the task was postponed.last_postpone_time(DateTime) — Date and time when the task was last postponed.merge_type(String) — Type of the current merge. Empty if it's a mutation.
