Unexpected side effects
This evening I finally got my internal DNS to work correctly, with forward and reverse lookups showing what I expected (ie, resolving properly).Then I went to check the referrer count on my blog, and got a 503 Resource temporarily unavailable.What the….. ?I checked that I could access tomcat and thus roller via (hostname):8000/roller and friends, bounced apache… and I could see www.jmcp.homeunix.com but the /blog link was still a 503.First thing to do is gather evidence. Over to the error_log file, where I saw this:
[Sun Oct 29 00:26:32 2006] [error] (146)Connection refused: proxy: AJP: attempt to connect to 59.167.244.18:8009 (www.jmcp.homeunix.com) failed [Sun Oct 29 00:26:32 2006] [error] ap_proxy_connect_backend disabling worker for (www.jmcp.homeunix.com) [Sun Oct 29 00:26:32 2006] [error] proxy: AJP: failed to make connection to backend: www.jmcp.homeunix.com [Sun Oct 29 00:26:40 2006] [error] proxy: AJP: disabled connection for (www.jmcp.homeunix.com) [Sun Oct 29 00:27:33 2006] [error] (146)Connection refused: proxy: AJP: attempt to connect to [IP address]:8009 (www.jmcp.homeunix.com) failed [Sun Oct 29 00:27:33 2006] [error] ap_proxy_connect_backend disabling worker for (www.jmcp.homeunix.com) [Sun Oct 29 00:27:33 2006] [error] proxy: AJP: failed to make connection to backend: www.jmcp.homeunix.com [Sun Oct 29 00:27:59 2006] [error] proxy: AJP: disabled connection for (www.jmcp.homeunix.com)
In my /etc/apache223/httpd.conf
file I had
ProxyPass /roller ajp://www.jmcp.homeunix.com:8009/roller ProxyPassReverse /roller ajp://www.jmcp.homeunix.com:8009/roller ProxyPass /blog ajp://www.jmcp.homeunix.com:8009/roller/page/jmcp ProxyPassReverse /blog ajp://www.jmcp.homeunix.com:8009/roller/page/jmcp
And of course a lookup on www.jmcp.homeunix.com
won’t show the CNAME that I setup to point to my webserver/tomcat zone, it’ll show my ISP-assigned static IP address.Doh!I quickly removed the .jmcp.homeunix.com
from those lines and bounced the apache223 service and all appears well. The final step was to gather a second opinion on the matter. For that I ssh’d to another system which I have access to and then ran
$ telnet www.jmcp.homeunix.com 80 ... GET /blog HTTP/1.0
and was promptly rewarded with the text which makes up the current entries in my blog.The point to make here is that if you put in a workaround for a problem which is then resolved, you definitely need to re-check your system(s) to ensure that that workaround is still applicable. If it’s not then you need to change it, or even remove it.
Technorati tags: topic:{Technorati}[Troubleshooting], topic:{Technorati}[Problem Solving], topic:{Technorati}[Evidence-based practice], topic:{Technorati}[BIND], topic:{Technorati}[Apache], topic:{Technorati}[AJP]