Hi Jonathan, I am not. This is encountered as soon as the app loads. Before request processing, I just make the engine and sessionmaker. Sessions are made from the sessionmaker per request. All of the functional code is on the SO link more or less. Is the overall pattern reasonable or have I messed up in some small detail? It seemed that the best practice was to just create sessions with sessionmaker and toss them after handling a request - at least this is what I gathered from browsing around. I am sure that at scale this is probably not super ideal, but this error is cropping up on localhost with two requests. Thanks in advance!
Raghu On Sunday, June 3, 2018 at 7:17:55 PM UTC-7, rvd wrote: > > Hi all, > > I am writing a Flask API that needs to communicate with many datastores, > Postgres on AWS RDS being one of them. I want to avoid Flask-SQLAlchemy > (trying to reduce package dependence); I think the standard SQLAlchemy > library should suffice. I have described the issue thoroughly here > <https://stackoverflow.com/questions/50669231/sqlalchemy-sessions-keep-dropping-after-a-few-minutes> > (code > is here as well). But here is the synopsis. When I use a Session object > in my app, for the first few requests, it works great. Then, if I wait for > a while and fire off another request, I get a Psycopg2 error about the > server closing off the connection unexpectedly. This is rather crippling. > I have spent a lot of time going through SO, asked in the SQLAlchemy IRC > channel, and tried many tutorials, and this seems to be a standard valid > pattern, so I am not sure what is going wrong. Should I not be removing the > session? Should I be using the @app.teardown_appcontext decorator (it > seems that if I just remove the sessions myself as I am doing now, I > shouldn't have to)? Should I be using a connection pool instead (it seems > that QueuePool is enabled under the hood by default anyway)? If it helps, > I am using the latest version of all packages, Python 3.6.5, and Postman to > send the requests to the server, which is running at localhost:5000. Any > advice would be much appreciated - thanks in advance! > > Best, > rvd > -- 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. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
