db8e60b82d
PostgresNode.pm set "max_wal_senders = 5" for replication testing, but this seems to be slightly too low for our current test suite. Slower buildfarm members frequently report "number of requested standby connections exceeds max_wal_senders" failures, due to old walsenders not exiting instantaneously. Usually, the test does not fail overall because of automatic walreceiver restart, but sometimes the failure becomes visible; and in any case such retries slow down the test. That value came in with commit 89ac7004d, but was soon obsoleted by f6d6d2920, which raised the built-in default from zero to 10; so that PostgresNode.pm is actually setting it to less than the conservative built-in default. That seems pretty pointless, so let's remove the special setting and let the default prevail, in hopes of making the TAP tests more robust. Likewise, the setting "max_replication_slots = 5" is obsolete and can be removed. While here, reverse-engineer a comment about why we're choosing less-than-default values for some other settings. (Note: before v12, max_wal_senders counted against max_connections so that the latter setting also needs some fiddling with.) Back-patch to v10 where the subscription tests were added. It's likely that the older branches aren't pushing the boundaries of max_wal_senders, but I'm disinclined to spend time trying to figure out exactly when it started to be a problem. Discussion: https://postgr.es/m/723911.1601417626@sss.pgh.pa.us
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. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.