Python Sql Alchemy 连接超时
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Sql Alchemy connection time Out
提问by Nazmul Hasan
I am using sqlalchemywith MySQL, and executing query with sql expression. When executing a number of query then it time out. I found an answerbut it is not clear to me. Please, any one can help me?
我正在使用sqlalchemywith MySQL，并使用 sql 表达式执行查询。当执行多个查询时，它会超时。我找到了答案，但我不清楚。拜托，有人可以帮我吗？
TimeoutError: QueuePool limit of size 5 overflow 10 reached, connection timed out, timeout 30
TimeoutError: QueuePool limit of size 5 overflow 10 达到，连接超时，超时 30
采纳答案by Greg
Whenever you create a new session in your code, make sure you close it. Just call session.close()
每当您在代码中创建新会话时，请确保将其关闭。打电话就行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.
当我收到此错误时，我以为我正在关闭所有会话，但我仔细查看了一种新方法，但我没有这样做。在该方法中关闭会话为我修复了这个错误。
回答by Aaren Shar
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:
在多线程模式下，如果您的并发请求数量远大于数据库连接池大小，则会抛出队列池限制大小为 5 溢出 10 达到error。试试这个：
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:
补充：上面的方法不是正确的方法。实际原因是db连接池用完了，没有其他可用的连接。最有可能的情况是您错过了释放连接。例如：
@app.teardown_appcontext
def shutdown_session(exception=None):
db_session.remove()
