Re: cfservd under load - db crash, MaxConnections

[Eric Sorenson]

On Wed, 8 Dec 2004 Mark.Burgess@iu.hio.no wrote:

> Just a note -- I have been and heard of people experiencing crashes
> due to berkeley libraries that are incorrectly compiled. There are
> so many versions now that it is easy to mix up header files and
> libraries, leading to core dumps.

I have also seen this happen, but it's not what is happening here.  Normal db
access is not problematic, I strongly suspect it was just that the 'dynamic' db
file got corrupted from an earlier problem and subsequent accesses to it would
puke & die.  I have seen this happen with the berkdb files on Cyrus sometimes.

This report is mostly a suggestion for other people who have been seeing 
crashes.
There's nothing (AFAICT) to be lost by letting cfservd re-create dynamic.

> I hope to be able to look into some recent bug reports in the next
> few days. The end of semester (exams) is rather demanding at the
> moment.

The other bug report's root cause was confirmed by Jim Wight. His mail
set me off on tracking this down, and here's the problem:

Running 'cfexecd -F' now invokes

snprintf(cfcom,CF_BUFSIZE-1,"%s/bin/cfagent -Q 
smtpserver,sysadm,fqhost,ipaddress,EmailMaxLines,EmailFrom,EmailTo -D 
fro$m_cfexecd",CFWORKDIR);

Which is intended to gather those variables from the parsed cfagent.conf
configs and return them on stdout, much like 'cfagent -z' returns the schedule.
However '-Q' does not short-circuit update.conf execution, but DOES ignore
splaytime! So it results in an immediate check of the inputs directory right
as 'cfexecd -F' gets triggered from cron. The attached patch should fix it:

diff -Naur cfengine-2.1.11/src/cfagent.c cfengine-2.1.11-eric/src/cfagent.c 
--- cfengine-2.1.11/src/cfagent.c	2004-10-26 00:44:31.000000000 -0700
+++ cfengine-2.1.11-eric/src/cfagent.c  2004-12-08 12:44:05.000000000 -0800
@@ -1734,6 +1734,7 @@
              }

           IGNORELOCK = true;
+          PARSEONLY = true;
           NOSPLAY = true;
           QUERYVARS = SplitStringAsItemList(optarg,',');
           break;



--

 - Eric Sorenson - Explosive Networking - http://eric.explosive.net -