nsqio/nsq

nsqd: refresh the address of nsqlookupd on DNS changes

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#1233 opened on Jan 14, 2020

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featurehelp wanted

Description

right now an nsqd client doesn't refresh it's ip connections to lookupd on lookupd DNS changes. this causes a problem on long running instances when a lookupd instance gets rebuilt.

Contributor guide

Tech stack
go
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.
1-3 hours
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.
mostly clear
Prerequisites
Go programmingDNS resolution conceptsNSQ architecture
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate how nsqd currently resolves and caches nsqlookupd addresses. Look at the connection initialization and periodic refresh mechanisms in the nsqd source code, likely in files like nsqd.go or lookups.go. Check if there is any DNS resolution caching or TTL handling. The fix may involve implementing a periodic DNS lookup or subscribing to OS level DNS change notifications.