[Representational purpose only] Making connection drops work for PG to PG#3958
Draft
Amogh-Bharadwaj wants to merge 4 commits intomainfrom
Draft
[Representational purpose only] Making connection drops work for PG to PG#3958Amogh-Bharadwaj wants to merge 4 commits intomainfrom
Amogh-Bharadwaj wants to merge 4 commits intomainfrom
Conversation
serprex
approved these changes
Feb 18, 2026
An issue was discovered recently where when a mirror running initial load from PG to PG is dropped, the copy process continues to run on source. A hint in pgx for CopyFrom reveals that context cancellation may not be acted upon while the reader is still open: ``` CopyFrom executes the copy command sql and copies all of r to the PostgreSQL server. Note: context cancellation will only interrupt operations on the underlying PostgreSQL network connection. Reads on r could still block. ``` This PR adds a check for context cancellation in the CopyInto methods for PG to PG, which should allow the copy process to be interrupted when the context is cancelled, preventing it from continuing to run on the source when a mirror is dropped.
Amogh-Bharadwaj
force-pushed
the
catch-context-cancel-copy
branch
from
ca97eca to
19cf45f
Compare
Amogh-Bharadwaj
changed the title
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
An issue was discovered recently where when a mirror running initial load from PG to PG is dropped, the copy process continues to run on source.
This PR shows an unideal reality of our use of PGX single connection reuse for syncing partitions in PG to PG initial load.
It involves replacing a lot of our commands' contexts with background contexts to bypass pgx's context watcher. It also fixes the pg_export_snapshot connection from lingering and taking a minute to be cleaned up.