subdomains sometimes not resolving

not sure where the problem lies on the food chain

[LifeinAsia]

We recently restructured our site to add several subdomains. When you go to subdomain1.domain.com it sometimes it takes a few second before the site is found or you get the dreaded "cannot find server" page. Other times it pops rght up. It's not consistant- it will work fine for a few page loads, then can't find the server or slow, then fine again.

I've used nslookup to do a lookup on the various subdomains and the address resolves right away. Even tries it using different nameservers. So it doesn't appear to be a DNS issue...

Any suggestions?

[LifeinAsia]

Update- as a test, we put the old site up on port 80 and the new subdomain site on port 8080. Both sites worked speedily with no problems.

Then switched things (old site on port 8080, subdomain site on port 80). Old site still pops up quickly, subdomain sites have the same problems of often not resolving. Tried completely turning off the old site- no change.

Very bizzare!

[LifeinAsia]

Final(?) updated- it seems like we tracked down the issue. It turns out that the laod balancer was throwing errors in the file it was checking to verify the server was up. This in turn caused the application server to keep restarting because too many errors were being thrown. While the application servers are restarting, the load balancer thinks the server is unavailable. If both servers happen to be restarting the applications at the same time, the load balancer thinks both are completely down and won't pass traffic. Oops, site not found.

Fixed one file and everyone seems to be happy now. Santa came early.