We were seeing email messages about
<pre>
 Can\'t connect to local MySQL server through socket
</pre>

<h2>Missing Databases</h2>
Beefing up the error messages revealed that the problem
was that certain databases were missing.
<p>For example, if a workgroup has no database associated
with it, then checking to see if it has annotations was
causing this message.
<p>The solution was to add a call to <code>sql_exists()</code>,
which will not send email if the table does not exist

<h2>Bad socket</h2>
<pre>
MySQL generated an error.This user is not logged in.Apache environment:
    SCRIPT_URI = http://embedded.eecs.berkeley.edu/mescal/images/compass_r.png
    HTTP_REFERER = http://embedded.eecs.berkeley.edu/mescal/forum/4.html
    REMOTE_HOST =

The error message is:
sql.inc.php: sql_query(): Failed to connect to database auth_3 on localhost as 
dbreader: Can\'t connect to local MySQL server through socket \'/tmp/mysql.sock\' 
(146)
------------------------------------------
A file has been created to keep track of repeats of this error within
a 60-minute period.

To delete this file, log onto andrews as root and
    rm -f  /home/www/wwwdata/delugeMail/35544c2c4df4fdd8403afcdf3d2e28a7
</pre>

The interesting thing here is that <code>146</code>
is the code in <code>/usr/include/sys/errno.h</code>
for
<pre>
#define ECONNREFUSED    146     /* Connection refused */
</pre>
<a href=\"http://publib.boulder.ibm.com/httpserv/ihsdiag/sidderror.html\">http://publib.boulder.ibm.com/httpserv/ihsdiag/sidderror.html</a>
suggests:
<blockquote>
Solaris 10 has an apparent problem, seen both on SPARC and x64 platforms, which results in the ECONNREFUSED failure even under relatively light loads. This issue is tracked by Sun under bug id 6460268. Customers encountering the \"Connection refused: SSL0600S\" message on Solaris 10 should check with Sun on the availability of a fix for this problem.

<p>March 14, 2007 status: Sun reported that fixes for this bug are now in the development build of Solaris. The fixes have not yet been backported to Solaris 10.

<p>June 1, 2007 status: Sun reported that a test/temporary patch is currently available for Solaris 10; it will be integrated in the next update of Solaris 10, which will probably release in July.
</blockquote>

<a href=\"http://au.sunsolve.sun.com/search/document.do?assetkey=1-34-10-1\">http://au.sunsolve.sun.com/search/document.do?assetkey=1-34-10-1</a>
says that this is fixed in 
<pre>
Patch-ID# 125174-02
Synopsis: SunOS 5.10: tl driver patch
BugId\'s fixed with this patch: 6452679 6460268 
Changes incorporated in this version: 
Date: Sep/14/07
</pre>