2 Commits (0fbfd37cefb7eb30c0fa8a158751c19ddeddf1f0)

Author	SHA1	Message	Date
Amit Kapila	e385a4e2fd	Prevent unintended dropping of active replication origins. ... Commit 5b148706c5 exposed functionality that allows multiple processes to use the same replication origin, enabling non-builtin logical replication solutions to implement parallel apply for large transactions. With this functionality, if two backends acquire the same replication origin and one of them resets it first, the acquired_by flag is cleared without acknowledging that another backend is still actively using the origin. This can lead to the origin being unintentionally dropped. If the shared memory for that dropped origin is later reused for a newly created origin, the remaining backend that still holds a pointer to the old memory may inadvertently advance the LSN of a completely different origin, causing unpredictable behavior. Although the underlying issue predates commit 5b148706c5, it did not surface earlier because the internal parallel apply worker mechanism correctly coordinated origin resets and drops. This commit resolves the problem by introducing a reference counter for replication origins. The reference count increases when a backend sets the origin and decreases when it resets it. Additionally, the backend that first acquires the origin will not release it until all other backends using the origin have released it as well. The patch also prevents dropping a replication origin when acquired_by is zero but the reference counter is nonzero, covering the scenario where the first session exits without properly releasing the origin. Author: Hou Zhijie <houzj.fnst@fujitsu.com> Author: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Shveta Malik <shveta.malik@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Discussion: https://postgr.es/m/TY4PR01MB169077EE72ABE9E55BAF162D494B5A@TY4PR01MB16907.jpnprd01.prod.outlook.com Discussion: https://postgr.es/m/CAMPB6wfe4zLjJL8jiZV5kjjpwBM2=rTRme0UCL7Ra4L8MTVdOg@mail.gmail.com	2 months ago
Amit Kapila	5b148706c5	Add optional pid parameter to pg_replication_origin_session_setup(). ... Commit 216a784829 introduced parallel apply workers, allowing multiple processes to share a replication origin. To support this, replorigin_session_setup() was extended to accept a pid argument identifying the process using the origin. This commit exposes that capability through the SQL interface function pg_replication_origin_session_setup() by adding an optional pid parameter. This enables multiple processes to coordinate replication using the same origin when using SQL-level replication functions. This change allows the non-builtin logical replication solutions to implement parallel apply for large transactions. Additionally, an existing internal error was made user-facing, as it can now be triggered via the exposed SQL API. Author: Doruk Yilmaz <doruk@mixrank.com> Author: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: Euler Taveira <euler@eulerto.com> Discussion: https://postgr.es/m/CAMPB6wfe4zLjJL8jiZV5kjjpwBM2=rTRme0UCL7Ra4L8MTVdOg@mail.gmail.com Discussion: https://postgr.es/m/CAE2gYzyTSNvHY1+iWUwykaLETSuAZsCWyryokjP6rG46ZvRgQA@mail.gmail.com	6 months ago