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cockroachdb / cockroach

CockroachDB — the cloud native, distributed SQL database designed for high availability, effortless scale, and control over data placement.
https://www.cockroachlabs.com
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kvserver: maybeAddRangeInfoToResponse called frequently under sysbench (0.1% cpu) #135806

Open tbg opened 2 days ago

tbg commented 2 days ago

Potentially on each request. I saw this take >3% on a blocking profile and it shows up on the CPU profile as well.

I ran BenchmarkSysbench/SQL/3node/oltp_read_write-1 with -test.benchtime=1000x and it printed 520 times, i.e. around 52k invocations.

    if rand.Intn(100) == 1 {
        fmt.Fprintln(os.Stderr, "NOW")
    }

This suggests that we have a caching problem, and this function isn't cheap.

image

Epic: CRDB-42584

Jira issue: CRDB-44725