Thanks. Looks like this works but we need to set it for every exception scenario. Just confirming if the exception_context is thread safe to set the attribute. Also, does this setting prevent pool invalidation on all sort of exceptions related to connections?
@event.listens_for(Engine, 'handle_error') def receive_handle_error(exception_context): if exception_context.invalidate_pool_on_disconnect: exception_context.invalidate_pool_on_disconnect = False On Thursday, January 6, 2022 at 10:03:55 AM UTC-8 Anupama Goparaju wrote: > Thanks, i will give it a try. > > On Thursday, January 6, 2022 at 5:23:09 AM UTC-8 Mike Bayer wrote: > >> I can't guarantee that overriding private methods is safe, no. >> >> there's a public API to disable errors resulting in invalidation, I >> suggest you use that. >> >> >> >> On Wed, Jan 5, 2022, at 7:35 PM, Anupama Goparaju wrote: >> >> I haven't read the response before and tried to skip the lib logic by >> overriding the function below in my child call extending the NullPool to do >> nothing. Is this safe to do? >> >> def _invalidate(self, connection, exception=None, _checkin=True): >> pass >> >> On Wednesday, January 5, 2022 at 4:33:01 PM UTC-8 Anupama Goparaju wrote: >> >> Great, thanks for the info. >> >> On Friday, November 26, 2021 at 9:30:02 AM UTC-8 Mike Bayer wrote: >> >> >> I've spent some time thinking about what might be being asked here. >> the only thing I can think of is that when a particular database connection >> is found to be in what we call a "disconnect" state, the connection is >> invalidated, so that the connection will reconnect and make a new >> connection. But also, this operation will typically assume the >> "disconnect" condition is that the database was restarted, or some other >> network condition has probably made all the connections that are pooled >> also invalid. So the entire pool will be invalidated in this case as well. >> >> Why someone might want to turn that off is if they are getting lots of >> invalidated connections for some other reason and they are not able to >> solve that problem, so they'd like the pool to not be invalidated totally. >> This means that if the database is restarted, and for example you have 20 >> pooled connections, you will in a high-request environment get up to 20 >> server errors unless pool_pre_ping is turned on so that the connections are >> refreshed one at at time. >> >> To disable the pool invalidation upon receipt of a single connection >> shown to be in a disconnect, implement the handle_error event: >> https://docs.sqlalchemy.org/en/14/core/events.html#sqlalchemy.events.ConnectionEvents.handle_error >> >> and then set invalidate_pool_on_disconnect to False: >> https://docs.sqlalchemy.org/en/14/core/connections.html?highlight=invalidate_pool_on_disconnect#sqlalchemy.engine.ExceptionContext.invalidate_pool_on_disconnect >> >> . >> >> >> >> On Fri, Nov 26, 2021, at 11:51 AM, Mike Bayer wrote: >> >> Im not sure if I understand the question? if you don't call >> .invalidate(), then the connection is not invalidated. >> >> what does "turn off" mean ? >> >> >> >> On Fri, Nov 26, 2021, at 11:17 AM, Anupama Goparaju wrote: >> >> Hi, >> >> Is there a way to safely turn off connection invalidation functionality >> (based on invalidation time set, all the connections created prior to the >> timestamp are invalidated) in sqlalchemy? >> >> >> https://github.com/Noethys/Connecthys/blob/master/connecthys/lib/sqlalchemy/pool.py#L574 >> >> Thanks, >> Anupama >> >> >> -- >> SQLAlchemy - >> The Python SQL Toolkit and Object Relational Mapper >> >> http://www.sqlalchemy.org/ >> >> To post example code, please provide an MCVE: Minimal, Complete, and >> Verifiable Example. 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