Several cluster fixes based on open ioredis PRs #4
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ozonep
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Change
Implements fixes from these PRs:
retryStrategyfor connection error redis/ioredis#1855Problem / Why
First fix:
When changing the instance type of a MemoryDB cluster, an in-place upgrade happens where new nodes are deployed with the same hostnames as the old ones. The old ones start returning MOVED to all queries, and after a while they are removed. The way ioredis reacts to this is it ends up in a loop of retrying commands and receiving MOVED. This loop is only broken once the old nodes are removed and the individual connections time out.
Second fix:
currently, cluster's "subscriber" check is done on "condition/preCondition" object level. But "condition.subscriber" property may be a boolean, not an object. So if "subscriber" as an object exists only on "prevCondition", we will never get there. This fix makes sure we pick the first available subscriber object (if any). This might be useful for us as AFAIK "bull" uses subscriptions when dealing with queues.
Third fix:
Currently
ioredisdoesn't utilize retryStrategy for connection event, so if connection to AWS is throttled due to high amount of calls (e.g. from Bull),ioredisdoesn't retry to connect like with other failed events. This PR fixed it.