Enable TCP Keepalives on TCP connections to MySQL #194
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…d DSN option, tests, and documentation.
|
Ah, fun. Apparently (*TCPConn).SetKeepAlivePeriod() is a go1.2-ism. |
|
Thanks for the PR! We haven't dropped Go 1.1 yet, Go 1.2 is still very new. I'd suggest to put the |
|
Makes sense. I've removed the keepalivePeriod DSN option for now, and added an AUTHORS entry for myself, making what's left a few line change to the connection startup. Take another look? -- Aaron |
|
LGTM |
julienschmidt
added a commit
that referenced
this pull request
Dec 13, 2013
Enable TCP Keepalives on TCP connections to MySQL
zenazn
added a commit
to zenazn/mysql
that referenced
this pull request
Apr 12, 2016
This patch adds a DSN-controllable way to call net.TCPConn's SetKeepAlivePeriod, which controls the kernel's keepalive behavior. This is a resubmission of the unmerged portion of go-sql-driver#194. Now that Go 1.2 has had a little bit of time to settle, hopefully this change will be a bit more palatable :)
zenazn
added a commit
to zenazn/mysql
that referenced
this pull request
Apr 12, 2016
This patch adds a DSN-controllable way to call net.TCPConn's SetKeepAlivePeriod, which controls the kernel's keepalive behavior. This is a resubmission of the unmerged portion of go-sql-driver#194. Now that Go 1.2 has had a little bit of time to settle, hopefully this change will be a bit more palatable :)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
We recently took had a production outage when we had an Amazon RDS MySQL instance lock up with many requests pending. We rebooted it, and it came up on a new IP, but we had to restart our Go apps to bring the site back up, which had hit their (*DB).SetMaxOpenConns() limit with outstanding requests. The go-mysql-driver doesn't enable TCP SO_KEEPALIVE and doesn't have any concept of client-side timeouts, so it would've waited forever for a response from a server that doesn't exist any more.
This patch enables the TCP SO_KEEPALIVE option after connecting to MySQL via TCP, which allows the kernel to notice when the server has dropped off of the network for an extended period (the Linux default is 2 hours), and then throw a TCP read error. Without this option set, a TCP connection will never timeout on its own.
For comparison, the mysql-connector in C (libmysql) unconditionally enables TCP keepalives at sql-common/client.c line 3834.
This also adds a DSN option "keepalivePeriod", which is passed to (*TCPConn).SetKeepAlivePeriod(), to change how often the kernel sends a keepalive packet to the server, soliciting a response.
I tried to use the existing style as much as possible, ran gofmt, updated the tests, and updated the documentation. Let me know I missed anything. Thanks!
-- Aaron