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The size of the I/O worker pool used to implement io_method=worker was previously controlled by the io_workers setting, defaulting to 3. It was hard to know how to tune it effectively. That is replaced with: io_min_workers=2 io_max_workers=8 (up to 32) io_worker_idle_timeout=60s io_worker_launch_interval=100ms The pool is automatically sized within the configured range according to recent variation in demand. It grows when existing workers detect that latency might be introduced by queuing, and shrinks when the highest-numbered worker is idle for too long. Work was already concentrated into low-numbered workers in anticipation of this logic. The logic for waking extra workers now also tries to measure and reduce the number of spurious wakeups, though they are not entirely eliminated. Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKG%2Bm4xV0LMoH2c%3DoRAdEXuCnh%2BtGBTWa7uFeFMGgTLAw%2BQ%40mail.gmail.com
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.