添加工作节点并使用 PostgreSQL + Citus 重新平衡分布式分片问题

Question

The cluster had 1 coordinator and 6 worker nodes. (environment: PostgreSQL 15 + Citus 11.1)

We want to add more worker nodes to it, so we executed SELECT * from citus_add_node('node-name', 5432); and SELECT rebalance_table_shards('table_name'); to got the messages as below:

ERROR: connection to the remote node 10.128.0.37:5432 failed with the following error: ERROR: subscription "citus_shard_move_subscription_10" does not exist

We have no way to solve it.

Hope somebody can help out. Thanks a lot!

We have tried Google and Citus official doc, but these is no solution for this case.

Answer 1

Chances are another error happened that in turn triggered this one, but this original error is masked by this follow up error. By looking at the logs on 10.128.0.37 you should be able to find out what the original error was.

Answer 2

You need to change configuration postgresql.conf:

wal_level = logical
max_replication_slots = 5 # has to be > 0
max_wal_senders = 5       # has to be > 0

You can read more here