Meta: Distributed Tracing

Instrument GitLab.com with distributed tracing

• GitLab-Workhorse Instrumentation POC: gitlab-org/gitlab-workhorse!295 (closed)
• Gitaly Distributed Tracing Instrumentation POC: gitlab-org/gitaly!867 (closed)
• GitLab-Rails Distributed Tracing Instrumentation POC: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/21280

Discussions

• Advantages/disadvantages of OpenTracing vs. OpenZipkin vs. OpenCensus
  • POC uses OpenTracing + Jaeger, but it's important to stress that it's a POC
• What is the minimum viable change?
  • Proposal: start at the high level:
    • Traces should connect:
      • Workhorse
      • Gitaly
      • Rails
    • Nice to have:
      • ActiveRecord (Postgres/mysql)
      • Redis
    • Out of scope for iteration 1:
      • GitLab Shell (Gem dependency issues will complicate this)
• This will be a useful tool for developers. How do we socialise and document this?
• Configuration
  • How do we switch this functionality on an off?
  • How do we configure it?
• Deployment
  • How do we stand up a jaeger/zipkin instance?
  • How do we secure it?