feat(app/inbound): introduce response duration metrics#4420
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Looks good, just a small nit about adding a comment with the rationale for choosing the bucket granularities just like you do for the PR.
this commit introduces a new middleware layer to the inbound proxy. this instruments inbound traffic with Prometheus telemetry that records response body latency, and emits a histogram of response body durations. the buckets are chosen to mimic the request and response buckets emitted by the outbound proxy, with their granularity flipped. in other words, the inbound proxy is more interested in fine-grained request body metrics than response body metrics, while the outbound proxy is more interested in fine-grained response body metrics than request body metrics. * #4418 * #4419 Signed-off-by: katelyn martin <kate@buoyant.io>
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this addresses review feedback, and introduces further documentation to the inbound proxy's response latency metrics. this commit also further polishes the outbound proxy's language around these constants, and adds mention to each half of the proxy regarding the other corresponding pair of metrics, to prevent drift in the future. to avoid churn, this commit phrases the inbound proxy's comments and language in terms that expect the forthcoming addition of a request latency layer to the inbound proxy, though that has not yet been implemented in this branch at time of writing. a todo comment is left in place to indicate this. Signed-off-by: katelyn martin <kate@buoyant.io>
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this commit introduces a new middleware layer to the inbound proxy. this instruments inbound traffic with Prometheus telemetry that records request body latency, and emits a histogram of request body durations. as in #4420, the buckets are chosen to mimic the request and response buckets emitted by the outbound proxy, with their granularity flipped. in other words, the inbound proxy is more interested in fine-grained request body metrics than response body metrics, while the outbound proxy is more interested in fine-grained response body metrics than request body metrics. * #4420 Signed-off-by: katelyn martin <kate@buoyant.io>
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this commit introduces a new middleware layer to the inbound proxy. this instruments inbound traffic with Prometheus telemetry that records request body latency, and emits a histogram of request body durations. as in #4420, the buckets are chosen to mimic the request and response buckets emitted by the outbound proxy, with their granularity flipped. in other words, the inbound proxy is more interested in fine-grained request body metrics than response body metrics, while the outbound proxy is more interested in fine-grained response body metrics than request body metrics. * #4420 Signed-off-by: katelyn martin <kate@buoyant.io>
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this commit introduces documentation for the inbound proxy metrics that have been added in recent edge releases. see these commits for more information: * linkerd/linkerd2-proxy#4420 * linkerd/linkerd2-proxy#4313 * linkerd/linkerd2-proxy#4180 * linkerd/linkerd2-proxy#4165 * linkerd/linkerd2-proxy#4127 Signed-off-by: katelyn martin <kate@buoyant.io>
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this commit introduces a new middleware layer to the inbound proxy.
this instruments inbound traffic with Prometheus telemetry that records
response body latency, and emits a histogram of response body durations.
the buckets are chosen to mimic the request and response buckets emitted
by the outbound proxy, with their granularity flipped. in other words,
the inbound proxy is more interested in fine-grained request body
metrics than response body metrics, while the outbound proxy is more
interested in fine-grained response body metrics than request body
metrics.