service unavailable

This is generally due to capacity issues on the web server. Work towards increasing the CPU/Memory available to the web server process and this should resolve.

So this is a 503 error? If so how can I capture these errors in my apace logs, I can't seem to find them in either access or error logs. My web server's load is not that high it averages around 8 for 16 cpu machines. All the web server has 12G of RAM which is plenty. And from my cacti graph there's always about 40 threads in wait mode while 8 are sending replies. Do I need to look elsewhere like mysql connections? I notice there quite a few slow queries getting logged, would that cause a 503? Also the web servers requestper second is averages around 110.

Yes, it could be the mySQL connections. If the threads hang because no connections or available or if they are taking too much of time; the connection might time out and you would get the 132 error.

The Apache internal error codes are not documented and its difficult to debug them.

Are you using a connector to re-direct the requests to another app/web server? If that is the case then the original HTTP error code would appear on that server logs.

Yes, we are using a load balancer to redirect the request. We normally get 503 errors service unvailable from apache when there is a Database I/O bottle such is backup and tarring of large files but this particular error says "Service Unavailable (Internal Reason: 132)". After googling on the web it looks like this internal reason code could be related to PHP codes? Is this more of a runtime/code php error rather than apache or mysql?

Looking at the default 503 error page for apache, the paragraph should look like this "
    The server is temporarily unable to service your
    request due to maintenance downtime or capacity
    problems. Please try again later."
Instead the error says this "This server is temporarily unable to service requests.(Internal-Reason: 132)"
This makes me believe its either PHP but most likely from the Load Balancer???? What you think.