envoyproxy/envoy

stats: retain Scopes for some amount of time after the last reference to them is dropped, to avoid leaking data when xds removes a scope

Open

#23,619 opened on Oct 21, 2022

View on GitHub
 (5 comments) (0 reactions) (0 assignees)C++ (5,373 forks)batch import
area/statsenhancementhelp wantedno stalebot

Repository metrics

Stars
 (27,997 stars)
PR merge metrics
 (Avg merge 8d) (378 merged PRs in 30d)

Description

Title: When an xDS update removes a cluster, any stats that get updated after the most recent sink or scrape will get dropped when the ScopeSharedPtr held in the cluster gets dropped.

Description:

To avoid this we should delay the destruction of the Scope for some time interval, perhaps a few minutes. We must be careful to accelerate the Scope destruction when the stats store gets destructed (server exit, or unit-test completion).

Contributor guide

Research direction
Implement delayed destruction of ScopeSharedPtr in stats module. Add a timer to retain scopes for a configurable interval after last reference is dropped. Ensure accelerated destruction on stats store destructor call.
Tech stack
cpp
Domain
backendobservability
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.
Half day
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.
Mostly clear
Prerequisites
C++Envoystats framework
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40