* fix(checkpointer): use AsyncConnectionPool for postgres to prevent stale connection errors (#3223)
Replace AsyncPostgresSaver.from_conn_string() with an explicit
AsyncConnectionPool that has check_connection enabled, so dead idle
connections are detected and replaced on checkout instead of raising
OperationalError.
* Potential fix for pull request finding
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
* Fixed the unit test error and lint error
* fix(checkpointer): add TCP keepalive to postgres connection pool (#3254)
Enable TCP keepalive probes on the AsyncConnectionPool to prevent
idle postgres connections from being dropped by the server or network
middleware. Combined with the existing check_connection callback, this
provides defense-in-depth against stale connection errors.
Fixes#3254
* Changed the code as review suggestion
---------
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
031d6fbcbe