envoyproxy/envoy

Cluster healthcheck uses wrong interval due to metric filtering

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#8,771 opened on Oct 25, 2019

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Description

Given an Envoy v1.11.1 node with cluster metrics excluded via StatsMatcher and cluster health checking enabled, when sending traffic to the cluster healthcheck is always run with no_traffic_interval 60s default interval.

The cause is the same as with https://github.com/envoyproxy/envoy/issues/8473 and https://github.com/envoyproxy/envoy/issues/8630, metrics are being used for application functionality.

In this case upstream_cx_total is the metric on which the dependency exists. Therefore the workaround is to whitelist it:

stats_config:
 stats_matcher:
  inclusion_list:
    patterns:
    - suffix: upstream_cx_total

Contributor guide

Research direction
Examine the health checker base implementation and trace how upstream cx total metric is used to determine the interval. Find an alternative mechanism that does not rely on a metric that can be filtered out.
Tech stack
cpp
Domain
backendinfrastructure
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C++Envoy configuration
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30