ah, errors and no admin_php
Have you checked stderr.log and error.log for related errors?
After a few retries, it eventually works, right?
When you get 503, please check if there is "admin_php" process running. If there is, try to strace those processes.
errors...
# tail -f stderr.log error.log
2009-03-17 14:23:46.084 [INFO] [X.X.X.X:32586-0#_AdminVHost] connection to [UDS://tmp/lshttpd/admin_php.sock] on request #0, Connection timed out!
2009-03-17 14:23:47.085 [NOTICE] [Rails:XXX.com:/] Send SIGKILL to process [15495] that won't stop.
2009-03-17 14:23:47.085 [INFO] [Rails:XXXXX.com:/] setuid child process, let parent kill it: 15495
2009-03-17 14:23:56.012 [INFO] [x.x.x.x:32586-0#_AdminVHost] ExtConn timed out while processing.
2009-03-17 14:23:56.012 [INFO] [x.x.x.x:32586-0#_AdminVHost] connection to [UDS://tmp/lshttpd/admin_php.sock] on request #0, Connection timed out!
2009-03-17 14:24:01.913 [INFO] [APVH_XXX.comSuphp:] pid list size: 1
2009-03-17 14:24:01.913 [INFO] [APVH_XXX.comSuphp:] add child process pid: 16550
2009-03-17 14:24:06.026 [INFO] [x.x.x.x:32586-0#_AdminVHost] ExtConn timed out while processing.
2009-03-17 14:24:06.026 [INFO] [x.x.x.x:32586-0#_AdminVHost] connection to [UDS://tmp/lshttpd/admin_php.sock] on request #0, Connection timed out!
2009-03-17 14:24:06.026 [NOTICE] [x.x.x.x:32586-0#_AdminVHost] oops! 503 Service Unavailable
2009-03-17 14:24:06.026 [NOTICE] [x.x.x.x:32586-0#_AdminVHost] Content len: 0, Request line:
GET /service/serviceMgr.php?act=restart&actId=XYZ.com&vl= HTTP/1.1
2009-03-17 14:24:07.002 [NOTICE] [Rails:XXX.com:/] Send SIGKILL to process [15495] that won't stop.
2009-03-17 14:24:07.002 [INFO] [Rails:XXX.com:/] setuid child process, let parent kill it: 15495
And no admin_php!
#ps aux | grep admin_php
root 16575 0.0 0.0 1832 496 pts/2 R+ 14:24 0:00 grep admin_php