Please DON'T underextimate this patch, and put it in vpopmail soon.
When you stop MySQL, all services working with vpopmail library and
using permanent connections to MySQL (like courier-authdaemon) will
stop working. You must restart them after any mysql failure.
With this patch, no need to restart any service of this kind.
Services will reopen MySQL connections automatically!
Tonino
At 16.05 29/05/2006, you wrote:
Greetings:
I don't know if anyone in here is encountering this problem (yet), but it has
been affecting me for the past few weeks - ever since I upgraded my MySQL
server to 5.0.19. It took quite a bit of digging, but I believe I have found
the problem.
To describe the problem: when you run vpopmail in MySQL mode, with
courier-authdaemond and MySQL v5.0 or later, you will find that for
the first 8
hours, everything works just fine, but after 8 hours, nobody will be able to
authenticate to the email server and you will see "MySQL server has gone away"
errors in the maillog.
The cause of the problem is that in MySQL 5.0 (and probably some 4.1
releases),
MySQL implements a new timeout definition for connections, a timeout that
ignores traffic. This timeout will shut down the socket thread from the MySQL
side. The problem is that the client (vchkpw and friends) do not
know/understand about this timeout and socket termination so they continue on
in ignorate bliss until they try to send to the socket and find that it's no
longer valid - literally "the server has gone away".
The fix is to simply destroy the internal flags and file handles
related to that
socket, rebuild a new one, and try again.
The included patch (inline and attached) implements this
fix. Please note that
there doesn't appear to be any way at this time to disable the timeout feature
in MySQL.
Please feel free to comment, tear apart, beat up, or otherwise rip
to shreads my
fix!
--
Ron Gage
(LPIC1 MCP A+ Net+)
Westland, Michigan
--- vmysql.c~ 2006-05-29 10:17:20.000000000 -0400
+++ vmysql.c 2006-05-29 10:17:20.000000000 -0400
@@ -465,7 +465,31 @@
);
if (mysql_query(&mysql_read,SqlBufRead)) {
fprintf(stderr, "vmysql: sql error[3]: %s\n",
mysql_error(&mysql_read));
- return(NULL);
+ /* Ron Gage - May 29, 2006 - With newer versions of MySQL, there is
such a thing
+ as a connection timeout regardless of activity. By default
under MySQL
5, this
+ timeout is 28800 seconds (8 hours). If your vpopmail
system runs fine
for the
+ first 8 hours, then stops authenticating, this timeout is
your problem
(especially
+ under authdaemond).
+
+ What this code does is when an error is encountered, it
first tries to
drop and
+ rebuild a connection to the SQL server and tries again. If
this second
attempt
+ fails, then something other than the connection timeout is
the problem.
This fix
+ need to be implemented in other places but in my setup
(Slackware 10.2,
netqmail,
+ vpopmail, courier-authdaemond, courier-imapd and a few
others), this is
always where
+ the auth attempt died with a "SQL server has gone away" error.
+ */
+
+ fprintf(stderr, "Attempting to rebuild connection to SQL server\n");
+ vclose();
+ verrori = 0;
+ if ( (err=vauth_open_read()) != 0 ) {
+ verrori = err;
+ return(NULL);
+ }
+ if (mysql_query(&mysql_read, SqlBufRead)) {
+ fprintf (stderr, "vmysql: connection rebuild failed: %s\n",
mysql_error(&mysql_read));
+ return(NULL);
+ }
}
if (!(res_read = mysql_store_result(&mysql_read))) {
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