It is not possible to set a socket timeout after connection is established

[MarcoFleres]

Problem:
Mysql server is too busy to read TCP queue, and responds with TCP Zero Window. This is to be expected from time to time, but if the server never clears the queue, the client will halt on socket write.

This could be solved by setting socket timeout. Currently, only connectTimeout can be set, and after connection is established, socket timeout is set back to 0.

[dougwilson]

Are you setting a timeout on your queries? https://github.com/mysqljs/mysql/blob/master/Readme.md#timeouts By default there is no timeout.

[MarcoFleres]

I see, i am going to test it.
...still, I think timeout should be set on a connection basis, apart from by query.

[dougwilson]

Yea, there are not any by default because timeout support was added but without being a breaking change so optional. The other issue is that since the protocol has no timeout support sometimes when the TCP connect is killed due to timeout on our side the query still took affect, and so it's hard to know what happened without assuming every query you make may or may not have committed when the timeout happens. Even queries like report generation or data migration that can take hours I see all the time, so just not sure what the right answer here is for all the use cases. So far this no timeout matches the provides libmysql C library behavior the MySQL project provides (and also the default mysql command line behavior) so I think if this was different it may create more confusion?