[jira] [Created] (TS-4341) When ATS hits `proxy.config.http.origin_max_connections` it has no limits on the number of requests that can be queued

["Thomas Jackson (JIRA)" <ji...@apache.org>]

Thomas Jackson created TS-4341:
----------------------------------

             Summary: When ATS hits `proxy.config.http.origin_max_connections` it has no limits on the number of requests that can be queued
                 Key: TS-4341
                 URL: https://issues.apache.org/jira/browse/TS-4341
             Project: Traffic Server
          Issue Type: Bug
            Reporter: Thomas Jackson


If you enable `proxy.config.http.origin_max_connections` to a specific origin, and that origin hits the max number of connections-- ATS will just reschedule the connection indefinitely. This is problematic because if the origin is down you can consume all available connections within ATS (UA side) waiting on the origin to finish up some requests.

I expect the requests past `proxy.config.http.origin_max_connections` to error out (5xx response code), after talking to [~jpeach@apache.org] that might be a bit too agressive-- as this is used by some to limit the number of connections to the origin (not just limit connection usage in ATS).

My proposed fix is to take a page out of haproxy's book-- and add a `proxy.config.http.origin_max_connections_queue` -- where we will allow a certain number of connections to queue up waiting on the origin, and if we exceed that number we 5xx the request.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)