Sql Alchemy connection time Out
Question:
I am using sqlalchemy with MySQL, and executing query with sql expression. When executing a number of query then it time out. I found an answer but it is not clear to me. Please, any one can help me?
TimeoutError: QueuePool limit of size 5 overflow 10 reached, connection timed out, timeout 30
Answers:
Whenever you create a new session in your code, make sure you close it. Just call session.close()
When I got this error I thought I was closing all of my sessions, but I looked carefully and there was one new method where I wasn’t. Closing the session in that method fixed this error for me.
In multi-thread mode, if your concurrent request num is much more than the db connection pool size, it will throw the Queue Pool limit of size 5 overflow 10 reached error. try with this:
engine = create_engine('mysql://', convert_unicode=True,
pool_size=20, max_overflow=100)
to add the pool size
Add: the method above is not a correct way. The actual reason is that db connection pool is used up, and no other available connection. The most probably situation is you miss to release connection. For example:
@app.teardown_appcontext
def shutdown_session(exception=None):
db_session.remove()
I am using sqlalchemy with MySQL, and executing query with sql expression. When executing a number of query then it time out. I found an answer but it is not clear to me. Please, any one can help me?
TimeoutError: QueuePool limit of size 5 overflow 10 reached, connection timed out, timeout 30
Whenever you create a new session in your code, make sure you close it. Just call session.close()
When I got this error I thought I was closing all of my sessions, but I looked carefully and there was one new method where I wasn’t. Closing the session in that method fixed this error for me.
In multi-thread mode, if your concurrent request num is much more than the db connection pool size, it will throw the Queue Pool limit of size 5 overflow 10 reached error. try with this:
engine = create_engine('mysql://', convert_unicode=True,
pool_size=20, max_overflow=100)
to add the pool size
Add: the method above is not a correct way. The actual reason is that db connection pool is used up, and no other available connection. The most probably situation is you miss to release connection. For example:
@app.teardown_appcontext
def shutdown_session(exception=None):
db_session.remove()