Bug 1256608 - mod_cluster undersizes the connection pool
Summary: mod_cluster undersizes the connection pool
Keywords:
Status: CLOSED DUPLICATE of bug 1338642
Alias: None
Product: JBoss Enterprise Web Server 2
Classification: JBoss
Component: mod_cluster
Version: 2.1.0
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
: ---
Assignee: Weinan Li
QA Contact: Michal Karm Babacek
URL:
Whiteboard:
Depends On: 1256607 1338642
Blocks:
TreeView+ depends on / blocked
 
Reported: 2015-08-25 06:21 UTC by Masafumi Miura
Modified: 2016-06-01 15:09 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 1256607
Environment:
Last Closed: 2016-05-30 17:39:52 UTC
Type: Bug


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker MODCLUSTER-466 0 Major Resolved mod_cluster undersizes the connection pool on httpd 2.2 2016-06-01 16:17:29 UTC

Description Masafumi Miura 2015-08-25 06:21:25 UTC
+++ This bug was initially created as a clone of Bug #1256607 +++

### Description of problem:

If all threads in a httpd child worker process are saturated with long requests, then all connections in the pool are exhausted, likely leaving none available for additional pings, which then fail with errors like:

    [error] (70007)The timeout specified has expired: proxy: ajp: failed to acquire connection for ...


### Steps to Reproduce:

1. Deploy a web application on EAP 6, which just do Thread.sleep() for a while
   (for example, 10-15 seconds. just longer than lbstatus_recalc_time, 5 seconds)

    ~~~
    <%
        long ms = 15000L;
        System.out.println("going to sleep... : " + ms + " ms");
        Thread.sleep(ms);
        System.out.println("done!");
    %>
    ~~~

2. Repeat sending concurrent requests to the web app via mod_cluster by apache bench
   (just exactly same concurrent number to MaxClients setting, or more than MaxClients)

   When you set MaxClients to 30, then execute the following:

    ~~~
    ab -c 30 -n 300 http://localhost/example/sleep.jsp
    ~~~


### Actual results:

You will see the "failed to acquire connection for ..." error message when status update is executed in background.


### Expected results:

No error message.


### Additional info:

https://issues.jboss.org/browse/MODCLUSTER-466

Comment 1 JBoss JIRA Server 2016-05-24 18:00:21 UTC
Radoslav Husar <rhusar@redhat.com> updated the status of jira MODCLUSTER-466 to Reopened

Comment 2 Michal Karm Babacek 2016-05-30 17:39:52 UTC

*** This bug has been marked as a duplicate of bug 1338642 ***

Comment 3 JBoss JIRA Server 2016-06-01 15:09:21 UTC
Michal Karm Babacek <mbabacek@redhat.com> updated the status of jira MODCLUSTER-466 to Resolved


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