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fix:dup conflict with balance

Open ninsmiracle opened this issue 2 years ago • 0 comments

What problem does this PR solve?

#1589

What is changed and how does it work?

There are two conflict may occure when opening duplication and balance: 1.load(one stage of duplication) with replica close Add a atomic parameter and check replica still have doing log load when it's closed. So how to end load and let replica close continue?There are two way could make it happen: -duplication step to next stage(shipping) -wait duplication do update_duplication_map,and it will remove_all_duplications when replica loss primary identity.

In remove_all_duplications,duplication will use a map named _replica to check the replica identity,so I protected it when replica close.

2.gc useless replica with replica close (close one replica twice) After replica connected with meta, meta will request for config to replica every 500ms. And replica server update itself's config when meta reply.In this logic ,on_node_query_reply_scatter2 will gc useless replica(which status is PS_INACTIVE),to be precise will set status from PS_INACTIVE TO PS_ERROR. When replica doing update_local_configuration,it will exec close action when status changed and new status is PS_INACTIVE or PS_ERROR. So I judge replica is already closed or doing close when replica exec close replica to deal with above problem.

Tests
  • Cluster test(mentioned in issue#1589)

In summary:

The earliest zlock coredump was caused by the necessity of acquiring a lock during the 'dup' load stage, which requires a lock from a member variable of the 'replica' class. However, at this point, the 'replica' had already been closed, related members are destructedresulting in obtaining,resulting zlock get an error _lock value.

The root cause of the replica being closed actually stems from the logic where the meta requests 'replica' for configuration, triggering a 'replica gc' process that sets the replica itself to 'PS_ERROR'. Based on the existing logic, both 'PS_INACTIVE' and 'PS_ERROR' trigger the 'begin_close' logic, with 'inactive' having a 10-minute delay and 'error' being executed immediately.

A double safeguard was implemented for the modification. Firstly, when enqueuing the close operation, it is checked whether the replica has already been closed or is in the process of closing. Secondly, during the execution of the close operation, in case it encounters a 'dup load', it is configured to enter the task queue with a delay of one minute.

ninsmiracle avatar Aug 29 '23 08:08 ninsmiracle