Add stats options to not prime the stats #40478
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cpuguy83
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I'm wondering if we could just "fix" this for 19.03. Basically just change the cli to make two requests. Old api clients we will still do the old behavior but for 19.03+ we do one. There is the possibility that other, non-docker cli clients may break. |
cpuguy83
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Feb 13, 2020
tonistiigi
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Feb 27, 2020
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https://github.com/moby/moby/pull/40478/files#r379079096
Otherwise lgtm
thaJeztah
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Feb 27, 2020
Metrics collectors generally don't need the daemon to prime the stats with something to compare since they already have something to compare with. Before this change, the API does 2 collection cycles (which takes roughly 2s) in order to provide comparison for CPU usage over 1s. This was primarily added so that `docker stats --no-stream` had something to compare against. Really the CLI should have just made a 2nd call and done the comparison itself rather than forcing it on all API consumers. That ship has long sailed, though. With this change, clients can set an option to just pull a single stat, which is *at least* a full second faster: Old: ``` time curl --unix-socket /go/src/github.com/docker/docker/bundles/test-integration-shell/docker.sock http://./containers/test/stats?stream=false\&one-shot=false > /dev/null 2>&1 real0m1.864s user0m0.005s sys0m0.007s time curl --unix-socket /go/src/github.com/docker/docker/bundles/test-integration-shell/docker.sock http://./containers/test/stats?stream=false\&one-shot=false > /dev/null 2>&1 real0m1.173s user0m0.010s sys0m0.006s ``` New: ``` time curl --unix-socket /go/src/github.com/docker/docker/bundles/test-integration-shell/docker.sock http://./containers/test/stats?stream=false\&one-shot=true > /dev/null 2>&1 real0m0.680s user0m0.008s sys0m0.004s time curl --unix-socket /go/src/github.com/docker/docker/bundles/test-integration-shell/docker.sock http://./containers/test/stats?stream=false\&one-shot=true > /dev/null 2>&1 real0m0.156s user0m0.007s sys0m0.007s ``` This fixes issues with downstreams ability to use the stats API to collect metrics. Signed-off-by: Brian Goff <cpuguy83@gmail.com>
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Fixed API version typo, should be good to go. |
tonistiigi
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Metrics collectors generally don't need the daemon to prime the stats
with something to compare since they already have something to compare
with.
Before this change, the API does 2 collection cycles (which takes
roughly 2s) in order to provide comparison for CPU usage over 1s. This
was primarily added so that
docker stats --no-streamhad something tocompare against.
Really the CLI should have just made a 2nd call and done the comparison
itself rather than forcing it on all API consumers.
That ship has long sailed, though.
With this change, clients can set an option to just pull a single stat,
which is at least a full second faster:
Old:
New:
This fixes issues with downstream's ability to use the stats API to
collect metrics.
Fixes #40437