Pound tells you the server is overloaded because your back end is telling
pound that it is overloaded.
10.5.4 503 Service Unavailable
The server is currently unable to handle the request due to a temporary
overloading or maintenance of the server. The implication is that this is a
temporary condition which will be alleviated after some delay. If known, the
length of the delay MAY be indicated in a Retry-After header. If no
Retry-After is given, the client SHOULD handle the response as it would for
a 500 response.
Note: The existence of the 503 status code does not imply that a
server must use it when becoming overloaded. Some servers may wish
to simply refuse the connection.
http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
From: John Hayward [mailto:[email protected]]
Sent: Wednesday, December 9, 2015 6:26 AM
To: [email protected]
Subject: [Pound Mailing List] 503 Service Unavailable: Back-end server is at
capacity
Hi pound people,
We have a pound server which is serving up to two load balancers at Amazon -
we are monitoring with icinga.
We have noticed the "503 Service Unavailable: Back-end server is at capacity
" message showing up in icinga.
It appears that this is from pound.
If so how does pound determine this situation?
Since there are two backend servers is it the situation that an existing
session which is connected to one of the backend servers is not able to
communicate with the backend server?
If not why does pound not direct to the other load balancer?
Any insite on how to prevent these events would be appreciated.
johnh...
