envoyproxy/envoy

EPOLLEXCLUSIVE support

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#14,718 opened on Jan 15, 2021

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area/listenerenhancementhelp wanted

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Description

In current implementation of envoy (if no configuration for REUSEPORT), multiple working threads would share the same LISTENING fd (to do accept),

In this case, there is the thundering bird problems if EPOLLEXCLUSIVE is NOT set, like this listening fd would wake up many worker to do accept but only 1 worker would succeed.

I was just wondering why envoy haven't support EPOLLEXCLUSIVE flag, is that because libevent don't have EPOLLEXCLUSIVE support or it's actually not a performance problem?

Thanks.

Contributor guide

Research direction
Investigate if libevent supports EPOLLEXCLUSIVE, and if not, propose a patch to add it; or consider using native epoll for listener sockets.
Tech stack
cpp
Domain
backend
Issue type
Feature
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.
Clear
Prerequisites
C++Linuxepoll
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60