The WAL receiver and WAL summarizer processes gain each one a call to pgstat_report_wal(), to make sure that they report their WAL statistics to pgstats, gathering data for pg_stat_io. In the WAL receiver, the stats reports are timed with status updates sent to the primary, that depend on wal_receiver_status_interval and wal_receiver_timeout. This is a conservative choice, but perhaps we could be more aggressive with the frequency of the stats reports. An interesting historical fact is that the WAL receiver does writes and syncs of WAL, but it has never reported its statistics to pgstats in pg_stat_wal. In the WAL summarizer, the stats reports are done each time the process waits for WAL. While on it, pg_stat_io is adjusted so as these two processes do not report any rows when IOObject is not WAL, making the view easier to use with less rows. Two tests are added in TAP, checking statistics for the WAL summarizer and the WAL receiver. Status updates in the WAL receiver are currently possible in the recovery test 001_stream_rep.pl. Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Discussion: https://postgr.es/m/Z8UKZyVSHUUQJHNb@paquier.xyz
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/.