langchain-ai/langgraph
1
0
Fork 0
mirror of https://github.com/langchain-ai/langgraph.git synced 2026-07-15 12:35:43 -04:00
Code Issues 314 Packages Projects Releases 17 Wiki Activity

[PR #6702] fix(checkpoint-postgres): skip acquiring the lock when using pooled connections #5232

New Issue
Closed
opened 2026-02-20 17:51:25 -05:00 by yindo · 0 comments
yindo commented 2026-02-20 17:51:25 -05:00
Owner
Copy Link
Copy Source

Original Pull Request: https://github.com/langchain-ai/langgraph/pull/6702

State: closed
Merged: Yes

When using an AsyncConnectionPool, connections are most likely† never shared by _cursor(). Calling AsyncConnectionPool.connection() removes the connection from the pool, so it cannot be used by any concurrent calls. As such, the lock inside _cursor() is redundant.

If the pool allows more than one connection, then _cursor() should be allowed to be concurrently called. As far as I can tell, the only way for that to occur is between _execute_batch() and sweep_ttl().

In the current setup, if the sweep_ttl() operation is slow, then that delays all batch operations. This might be the trigger of the behaviour I was seeing in #6701.

† In theory, someone could implement AsyncConnectionPool to return a shared connection, but that would be redundant in langgraph.

**Original Pull Request:** https://github.com/langchain-ai/langgraph/pull/6702 **State:** closed **Merged:** Yes --- When using an `AsyncConnectionPool`, connections are most likely† never shared by `_cursor()`. Calling `AsyncConnectionPool.connection()` removes the connection from the pool, so it cannot be used by any concurrent calls. As such, the lock inside `_cursor()` is redundant. If the pool allows more than one connection, then `_cursor()` should be allowed to be concurrently called. As far as I can tell, the only way for that to occur is between `_execute_batch()` and `sweep_ttl()`. In the current setup, if the `sweep_ttl()` operation is slow, then that delays all batch operations. This might be the trigger of the behaviour I was seeing in #6701. † In theory, someone could implement `AsyncConnectionPool` to return a shared connection, but that would be redundant in langgraph.
yindo added the pull-request label 2026-02-20 17:51:25 -05:00
yindo closed this issue 2026-02-20 17:51:25 -05:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
agents
awaiting author revision
bug
change
chat models
checkpointer
ci
code quality
code quality
dependencies
documentation
drawing
duplicate
enhancement
good first issue
help wanted
invalid
maintainer
meta
missing information
not maintained by langchain
open-swe-auto
open-swe-max
open-swe-max-auto
pending
performance
pull-request
Mirrored from GitHub Pull Request
 question
requires design
sdk
server
stale
studio
tests
type checking
usage question
v0.5
v1.1
No Label pull-request
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
yindo
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: langchain-ai/langgraph#5232
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?