Sean Chittenden: Scaling WAL apply performance on Followers -- PGCon 2018
Channel: PGCon
Date: 07/11/2018

DBAs struggling with replication lag is nothing new. A large volume of data or write IO comes into the system and the followers struggle to keep up. pg_prefaulter was written to eliminate replication lag on followers and also improves database startup times.

If your database is under 24/7 write workload, has periodic replication lag that is unacceptable, or want to reduce the startup time of PostgreSQL, pg_prefaulter will help all three of these scenarios.

At Joyent we use PostgreSQL as the metadata tier for our object storage system, Manta. This talk chronicles how we identified our source of replication lag and why we found it necessary to write pgprefaulter. pgprefaulter is a sidecar process for PostgreSQL written in Go that pre-fetches pages from disk and loads them into the operating system's filesystem cache before PostgreSQL requests them during the startup and application of WAL records.

https://www.pgcon.org/2018/