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Message #00183
Re: [MySQL Proxy] Connection Close and ERROR 2013
Hey!
On Jun 11, 2009, at 2:35 PM, Erwan Ben Souiden wrote:
On Thu, Jun 11, 2009 at 12:04 PM, Kay Röpke<Kay.Roepke@xxxxxxx> wrote:
First, thank you to answer me (and how fast !! :) )
Sometimes, not always fast :)
My configuration :
mysql-proxy v 0.7.1 (from
http://code.launchpad.net/mysql-proxy/0.7/0.7.1/+download/mysql-proxy-0.7.1.tar.gz)
compiled with no particular option
rw-splitting.lua script has been patched thanks to the following
patch
:
https://code.launchpad.net/~diego-fmpwizard/mysql-proxy/
bug-43424/+merge/4259
Ok, makes sense.
Have you tried this with a binary from
http://dev.mysql.com/downloads/mysql-proxy? Shouldn't make a
difference, but
it's worth a try.
Nop I didn't try with this binary. I will do some tests with it (just
to be sure)
I have a question about the patch from Diego : why is still in "Needs
review" status ? I understand the different changes but I'm not enough
confident with the rw-splitting.lua script to understand some
commented lines (lines 63 and 79 of the patch)... If you have any clue
about it, I'm really interested ! :)
Well, it's in review because … it needs someone to look at :)
Since I haven't actually looked at the patch yet (too. much. work.) I
can't really comment on why the lines
were commented out, sorry.
In one version or another the patch will go into version 0.8, though.
However, what I think is going on might be related to this bug
report:
http://bugs.mysql.com/bug.php?id=28359
The gist is that this error can be caused by exceeding the
connect_timeout
(the default is rather small) which causes the server to just close
the
connection leading to error 2013 on the client.
Actually I have no problem when I didn't use the proxy :( .
That's good or bad, depending on how you look at it.
OTOH it might just mean that proxy changes the timing of things, and
that it's not
necessarily proxy's fault. But since we don't have any more data, we
can't tell.
Nevertheless, try to increase the connect_timeout even further (just
for testing, of course,
if this is a production machine!) to see if the errors with proxy go
away/get less.
What is it set to in your mysqlds? Which versions are you running?
(mmmh I
think we should log the server versions we connect to, I'll file a
feature
request.)
Oops ! I forgot to mention that ! I use a mysqld 5.0.77
Ok, so fairly recent. I asked because sometimes older mysqld versions
have known bugs in
protocol handling, so I wanted to eliminate that possiblity.
Are your backend servers rather busy? If so that might lead to what's
described in the bug report mentioned above. If not, it might be a
problem
with how we assemble the handshake packet, or a more general
problem with
the connection pool, but all of that is pure speculation at this
point.
How often does this occur? If it's quite frequent, could you get a
trace for
that connection using wireshark so we can see what the actual
packets are?
(Again, maybe it's worthwhile for us to include an option to dump the
traffic for each connection to a file - that could greatly help with
debugging!)
It often occurs when I got the first error.
I'm probably wrong but I think at the beginning there is no connection
in the pool... so I have no problem to create new one... Then I got
the first error and when I try one more time, I have no problem. But
next try I get the error and next it's ok ! And so on...
So with my tiny knowledge of this subject I presume I have a problem
with the connection pool :(
It sounds like it, yes. The packet data will show.
cheers,
-k
--
Kay Roepke
Software Engineer, MySQL Enterprise Tools
Sun Microsystems GmbH Sonnenallee 1, DE-85551 Kirchheim-Heimstetten
Geschaeftsfuehrer: Thomas Schroeder, Wolfang Engels, Wolf Frenkel
Vorsitz d. Aufs.rat.: Martin Haering HRB MUC 161028
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