Redis: Replication Under Load Gets a Fix
Two separate fixes address replicas falling behind and busy-looping under heavy write traffic, while smaller patches correct a dead expire trigger and restore parallel build speed. Together they tighten up reliability in the replication path and developer build tooling.
Duration: PT2M48S
Episode overview
This episode is a short developer briefing from Redis.
It explains recent repository work in plain language.
- Show: Redis
- Published: 2026-07-14T13:13:36Z
- Audio duration: PT2M48S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
Good day, and welcome to the Redis briefing for July 14th, 2026.
Today's biggest signal is replication reliability under load. Two merged fixes tackle related failure modes that only show up when traffic gets heavy.
First, PR 15447 from Ozan Tezcan changes how the server feeds data to replicas. Previously, Redis wrote to replicas only once per event loop, at the very end. Under a heavy write burst, that meant a big chunk of data landing all at once, overflowing the socket buffer, and eventually tripping the client output buffer…
Second, PR 15329 from Mincho Paskalev fixes a busy-loop bug in the IO thread path, tied to issue 15311. A replica client could keep a write handler installed even after all data was flushed, causing the IO thread to spin continuously once traffic went idle. The fix uninstalls that handler properly when a client is…
A second theme is quiet correctness fixes. PR 15412 from pjs7678 fixes a unit mismatch in the expire cycle: a stale-key percentage was being compared against a threshold in the wrong scale, meaning the FAST expire trigger has been effectively dead code since Redis 6.0. It's fixed now with a simple scaling correction.
On tooling, PR 15459 restores…
Nearby episodes from Redis
- Edge Cases in Numeric Boundaries
- Weekly Recap - Security Fixes, Crash Hardening, and the Modules Build Overhaul
- Correctness Fixes Under the Hood
- Tightening Object Internals
- Duplicate Fixes and Event Loop Cleanup
- Modules Consolidation and Core Performance Gains
- Closing the Gaps Around Trust Boundaries
- Module Build Overhaul and a Cautious Revert