Debezium Postgres Kafka 连接器心跳未提交 LSN

Question

我在 AWS RDS 上有一个 Postgres Db 和一个在 table 上侦听的 kafka 连接器 (Debezium Postgres)。连接器的配置：

{
  "name": "my-connector",
  "config": {
    "connector.class": "io.debezium.connector.postgresql.PostgresConnector",
    "database.dbname": "my_db",
    "database.user": "my_user",
    "max.queue.size": "32000",
    "slot.name": "my_slot",
    "tasks.max": "1",
    "publication.name": "my_publication",
    "database.server.name": "postgres",
    "heartbeat.interval.ms": "1000",
    "database.port": "my_port",
    "include.schema.changes": "false",
    "plugin.name": "pgoutput",
    "table.whitelist": "public.my_table",
    "tombstones.on.delete": "false",
    "database.hostname": "my_host",
    "database.password": "my_password",
    "name": "my-connector",
    "max.batch.size": "10000",
    "database.whitelist": "my_db",
    "snapshot.mode": "never"
  },
  "tasks": [
    {
      "connector": "my-connector",
      "task": 0
    }
  ],
  "type": "source"
}

table 不像其他 table 那样频繁更新，这最初导致复制延迟如下：

SELECT slot_name,
  pg_size_pretty(pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)) as replicationSlotLag,
  pg_size_pretty(pg_wal_lsn_diff(pg_current_wal_lsn(), confirmed_flush_lsn)) as confirmedLag,
  active
FROM pg_replication_slots;
           slot_name           | replicationslotlag | confirmedlag | active
-------------------------------+--------------------+--------------+--------
 my_slot                       | 1664 MB            | 1664 MB      | t

它会变得如此之大，以至于可能会耗尽所有磁盘 space。

我添加了心跳，如果我登录到 kafka 代理并像这样设置控制台消费者：./kafka-console-consumer.sh --bootstrap-server my.broker.address:9092 --topic __debezium-heartbeat.postgres --from-beginning --consumer.config=/etc/kafka/consumer.properties 它会转储所有心跳消息，然后每 1000 毫秒显示一个新消息。

但是，插槽的大小仍在不断增长。如果我做一些事情，比如在 table 中插入一条虚拟记录，它会将插槽设置回一个小的滞后，这样就可以了。

虽然我很想用心跳来做这件事。我不想插入定期消息，因为这听起来会增加复杂性。为什么心跳不减小插槽大小？

Answer 1

请看https://debezium.io/documentation/reference/1.0/connectors/postgresql.html#wal-disk-space

您确实需要发出定期消息，但现在有帮助 - https://issues.redhat.com/browse/DBZ-1815

Debezium Postgres Kafka 连接器心跳未提交 LSN

Debezium Postgres Kafka Connector heartbeat is not committing LSN

postgresql

apache-kafka

apache-kafka-connect

debezium