micrometer-metrics/micrometer

DNS, SSL, and TCP metrics for Apache HttpClient

Closed

#1,617 opened on Oct 1, 2019

View on GitHubContributor guide
 (5 comments) (0 reactions) (1 assignee)Java (1,131 forks)batch import
enhancementhelp wantedinstrumentationmodule: micrometer-core

Repository metrics

Stars
 (4,882 stars)
PR merge metrics
 (Avg merge 1d 21h) (100 merged PRs in 30d)

Description

Add metrics for:

  1. DNS resolution time (inject custom DnsResolver, delegating to the user-provided resolver, and timing).
  2. SSL handshake time (inject SSLConnectionSocketFactory, delegating).
  3. TCP connect time (also in custom SSLConnectionSocketFactory).

Apply these on custom PoolingHttpClientConnectionManager.

Feedback suggests that DNS resolution/SSL handshake can go up dramatically in noisy neighbor situations.

Originally posted by @jkschneider in https://github.com/micrometer-metrics/micrometer/issues/533#issuecomment-446713248

Contributor guide

Research direction
Investigate injecting custom DnsResolver and SSLConnectionSocketFactory into PoolingHttpClientConnectionManager. Review Apache HttpClient documentation for hooks. Examine existing Micrometer instrumentation patterns for timing using Timer. Consider the noisy neighbor scenario mentioned in the issue. Look at the original comment by jkschneider for context.
Tech stack
java
Domain
observability
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaApache HttpClientMicrometerSSL/TLS basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35