2023-06-14 15:46:56 +00:00
|
|
|
---
|
|
|
|
|
slug: /en/operations/system-tables/kafka_consumers
|
|
|
|
|
---
|
|
|
|
|
# kafka_consumers
|
|
|
|
|
|
|
|
|
|
Contains information about Kafka consumers.
|
|
|
|
|
Applicable for [Kafka table engine](../../engines/table-engines/integration/kafka) (native ClickHouse integration)
|
|
|
|
|
|
|
|
|
|
Columns:
|
|
|
|
|
|
|
|
|
|
- `database` (String) - database of the table with Kafka Engine.
|
|
|
|
|
- `table` (String) - name of the table with Kafka Engine.
|
2023-06-14 16:19:43 +00:00
|
|
|
- `consumer_id` (String) - Kafka consumer identifier. Note, that a table can have many consumers. Specified by `kafka_num_consumers` parameter.
|
2023-06-14 15:46:56 +00:00
|
|
|
- `assignments.topic` (Array(String)) - Kafka topic.
|
2023-06-14 16:19:43 +00:00
|
|
|
- `assignments.partition_id` (Array(Int32)) - Kafka partition id. Note, that only one consumer can be assigned to a partition.
|
2023-06-14 15:46:56 +00:00
|
|
|
- `assignments.current_offset` (Array(Int64)) - current offset.
|
|
|
|
|
- `last_exception_time`, (DateTime) - timestamp when the most recent exception was generated.
|
|
|
|
|
- `last_exception`, (String) - text of the most recent exception.
|
|
|
|
|
- `last_poll_time`, (DateTime) - timestamp of the most recent poll.
|
|
|
|
|
- `num_messages_read`, (UInt64) - number of messages read by the consumer.
|
|
|
|
|
- `last_commit_time`, (DateTime) - timestamp of the most recent poll.
|
|
|
|
|
- `num_commits`, (UInt64) - total number of commits for the consumer.
|
|
|
|
|
- `last_rebalance_time`, (DateTime) - timestamp of the most recent Kafka rebalance
|
|
|
|
|
- `num_rebalance_revocations`, (UInt64) - number of times the consumer was revoked its partitions
|
|
|
|
|
- `num_rebalance_assignments`, (UInt64) - number of times the consumer was assigned to Kafka cluster
|
|
|
|
|
- `is_currently_used`, (UInt8) - consumer is in use
|
|
|
|
|
|
|
|
|
|
Example:
|
|
|
|
|
|
|
|
|
|
``` sql
|
|
|
|
|
SELECT *
|
|
|
|
|
FROM system.kafka_consumers
|
|
|
|
|
FORMAT Vertical
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
``` text
|
|
|
|
|
Row 1:
|
|
|
|
|
──────
|
|
|
|
|
database: test
|
|
|
|
|
table: kafka
|
|
|
|
|
consumer_id: ClickHouse-instance-test-kafka-1caddc7f-f917-4bb1-ac55-e28bd103a4a0
|
|
|
|
|
assignments.topic: ['system_kafka_cons']
|
|
|
|
|
assignments.partition_id: [0]
|
|
|
|
|
assignments.current_offset: [18446744073709550615]
|
|
|
|
|
last_exception_time: 1970-01-01 00:00:00
|
|
|
|
|
last_exception:
|
|
|
|
|
last_poll_time: 2006-11-09 18:47:47
|
|
|
|
|
num_messages_read: 4
|
|
|
|
|
last_commit_time: 2006-11-10 04:39:40
|
|
|
|
|
num_commits: 1
|
|
|
|
|
last_rebalance_time: 1970-01-01 00:00:00
|
|
|
|
|
num_rebalance_revocations: 0
|
|
|
|
|
num_rebalance_assignments: 1
|
|
|
|
|
is_currently_used: 1
|
|
|
|
|
|
|
|
|
|
```
|
