Details
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Improvement
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Status: Resolved
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Normal
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Resolution: Fixed
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None
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None
Description
When read_repair is not 1.0, we send the request to one node for some of the requests. When a node goes down or when a node is too busy the client has to wait for the timeout before it can retry.
It would be nice to watch for latency and execute an additional request to a different node, if the response is not received within average/99% of the response times recorded in the past.
CASSANDRA-2540 might be able to solve the variance when read_repair is set to 1.0
1) May be we need to use metrics-core to record various Percentiles
2) Modify ReadCallback.get to execute additional request speculatively.
Attachments
Attachments
Issue Links
- relates to
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CASSANDRA-5932 Speculative read performance data show unexpected results
- Resolved
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CASSANDRA-5014 Convert timeout from milli second to micro second.
- Resolved