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Aleksey Yeschenko commented on CASSANDRA-8368:
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bq. So you mean the hints will eventually be replayed even after
max_hint_window_in_ms goes by? Or just that you will store a hint for it after
max_hint_window_in_ms?
You misunderstand what {{max_hint_window_in_ms}} means. It's not about replay,
it's only about storing or not storing a hint in the first place.
Batchlog-created hints will always be stored.
Whether or not they get replayed in the end depends solely on hint's TTL (but
that same semantics is in place for BL entires, they have the same TTL).
> Consider not using hints for batchlog replay, in any capacity
> -------------------------------------------------------------
>
> Key: CASSANDRA-8368
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8368
> Project: Cassandra
> Issue Type: Bug
> Reporter: Aleksey Yeschenko
> Fix For: 3.0.0 rc1
>
>
> Currently, when replaying a batch, if a request times out, we simply write a
> hint for it and call it a day.
> It's simple, but it does tie us to hints, which some people prefer to disable
> altogether (and some still will even after CASSANDRA-6230).
> It also potentially violates the consistency level of the original request.
> As an alternative, once CASSANDRA-7237 is complete, I suggest we stop relying
> on hints at all, and do this instead:
> 1. Store the consistency level as batch metadata
> 2. On replay, hint in case of a timeout, but not if the node is down as per FD
> 3. If CL is met, consider the batch replayed and discard it, but not account
> the hints towards CL (as per usual write patch), unless CL.ANY is being used
> 4. If CL is *not* met, write a new batch with contents of the current one,
> but with timeuuid set in the future, for later replay (delayed by fixed
> configurable time or exponentially backed off). With that new batch store the
> list of nodes we've delivered the hint to, so that next time we replay it we
> don't waste writes.
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