[Feature Request] Optimize indexing performance in replica shard

[kkewwei]

Is your feature request related to a problem? Please describe

It's known thatindexingStrategyForOperation will be invoked by both the primary and replica to ascertain the index strategy, which is very performance-intensive. Given that the data on primary and replica are same, the index strategy must be same between the two. Therefore, rather than the replica computing the strategy independently, index strategy can be passed from primary to replica directly, to avoid this performance-intensive action, thereby improving the index performance of the replica.

Related component

Indexing:Performance

Describe alternatives you've considered

No response

Additional context

No response

[soosinha]

[Triage - attendees 1 2 3 4]

We discussed in the triage meeting that during failover and internal retry scenarios, it might be useful for the replica to compute the indexing strategy independently. @kkewwei Have you thought about all the cases ?

[kkewwei]

We discussed in the triage meeting that during failover and internal retry scenarios, it might be useful for the replica to compute the indexing strategy independently. @kkewwei Have you thought about all the cases ?

@soosinha, I have't thought too much. In my side, It has a greater effect in replica indexing, of course including internal retry, It seems worthwhile to implement, and i like have a try in replica indexing first.

[navneet1v]

@kkewwei just out if curiosity how much latency improvement do you expect here if replicas are not creating their own index strategy?

[kkewwei]

@kkewwei just out if curiosity how much latency improvement do you expect here if replicas are not creating their own index strategy?

@navneet1v, I am not sure either. In the scenario of frequent updates, I see that writing thread is actively engaged here. When indexing, it needs to query all segments of this shard to determine whether the particular doc exists and its version. I will try to use opensearch-benchmark to draw some preliminary conclusion.