Connect without proxy information hangs if "proxy_protocol_networks" is enabled

[OrNix]

Server version: 5.6.26-74.0-log Percona Server (GPL), Release 74.0, Revision 32f8dfd
2.6.32-504.23.4.el6.x86_64

proxy_protocol_networks=192.168.167.70
Connects from 192.168.167.70 with proxy information from haproxy work fine. But simple mysql connect from this address (without proxy information) hangs:

192.168.167.70# mysql --host 192.168.167.73 -u wm_ro -p
Enter password:
...
...

And in processlist on server there is something like:
Connect 570935 login unauthen connecting 58:36.942

[Laurynas Biveinis (laurynas-biveinis)]

This behavior is necessitated by the protocol: in MySQL protocol, server speaks first; in proxy protocol, client speaks first. Here both parties wait for the other one to send something.

Converting this to doc bug so that this behavior is documented.

Additionally, the connection timeout in such scenario might be too long, see bug 1502411.

[OrNix (ornixx)]

So is it impossible to make both mysql and haproxy connections workable from the same IP?

[Laurynas Biveinis (laurynas-biveinis)]

Right. Protocol issues aside, this is also specified in the proxy protocol specification, to the best of my understanding:

"The receiver MUST be configured to only receive the protocol described in this
specification and MUST not try to guess whether the protocol header is present
or not. "

http://www.haproxy.org/download/1.5/doc/proxy-protocol.txt

[wodesuck (wodesuck)]

I think there should be an option for the mysql client that make it enable to send a proxy protocol header. Client may send a LOCAL command as proxy protocol specified, indicating real connection endpoints are used. This would make more convenience and flexible while working with proxy protocol.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-1659