a36164e746
Previously, a WAL receiver freshly started would set its state to WALRCV_STREAMING immediately at startup, before actually establishing a replication connection. This commit introduces a new state called WALRCV_CONNECTING, which is the state used when the WAL receiver freshly starts, or when a restart is requested, with a switch to WALRCV_STREAMING once the connection to the upstream server has been established with COPY_BOTH, meaning that the WAL receiver is ready to stream changes. This change is useful for monitoring purposes, especially in environments with a high latency where a connection could take some time to be established, giving some room between the [re]start phase and the streaming activity. From the point of view of the startup process, that flips the shared memory state of the WAL receiver when it needs to be stopped, the existing WALRCV_STREAMING and the new WALRCV_CONNECTING states have the same semantics: the WAL receiver has started and it can be stopped. Based on an initial suggestion from Noah Misch, with some input from me about the design. Author: Xuneng Zhou <xunengzhou@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Rahila Syed <rahilasyed90@gmail.com> Discussion: https://postgr.es/m/CABPTF7VQ5tGOSG5TS-Cg+Fb8gLCGFzxJ_eX4qg+WZ3ZPt=FtwQ@mail.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/.