# Latency quantiles time window?

**URL:** https://forums.foundationdb.org/t/latency-quantiles-time-window/3204
**Category:** Using FoundationDB
**Created:** [March 11, 2022, 2:27am UTC](https://forums.foundationdb.org/t/latency-quantiles-time-window/3204 "2022-03-11T02:27:47Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![tudor](https://sea1.discourse-cdn.com/foundationdb/user_avatar/forums.foundationdb.org/tudor/32/1253_2.png) [@tudor](https://forums.foundationdb.org/u/tudor)
#### Post date: [March 11, 2022, 2:27am UTC](https://forums.foundationdb.org/t/latency-quantiles-time-window/3204/1 "2022-03-11T02:27:47Z")

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The latency statistics (such as, for example `commit_latency_statistics` for the `proxy` role) report quantiles (p25, p90, p95, p99, p99.9).

What’s the time window used to compute the quantiles? Is it “since the beginning of time” (since the process started)? If so, can it be reset?

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<div class="post-metadata">

### Author: ![Imperatorx](https://avatars.discourse-cdn.com/v4/letter/i/d2c977/32.png) [@Imperatorx](https://forums.foundationdb.org/u/Imperatorx)
#### Post date: [March 11, 2022, 12:25pm UTC](https://forums.foundationdb.org/t/latency-quantiles-time-window/3204/2 "2022-03-11T12:25:48Z")

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> [@tudor](#):
>
> `commit_latency_statistics`

I think its used here [https://github.com/apple/foundationdb/blob/402fa4dd9e2151807fc8a89d6471f2da41e41d4a/fdbserver/ProxyCommitData.actor.h#L115](https://github.com/apple/foundationdb/blob/402fa4dd9e2151807fc8a89d6471f2da41e41d4a/fdbserver/ProxyCommitData.actor.h#L115)

and defined here [https://github.com/apple/foundationdb/blob/944ec484153c3a8c40dc6d8dd3b3e5f87563cb60/fdbclient/ServerKnobs.cpp#L813](https://github.com/apple/foundationdb/blob/944ec484153c3a8c40dc6d8dd3b3e5f87563cb60/fdbclient/ServerKnobs.cpp#L813)

with a default value of 60 seconds