Uploaded image for project: 'mod_cluster'
  1. mod_cluster
  2. MODCLUSTER-433

remove_session_route causes an infinite loop when parsing jsessionid out of URLs

    XMLWordPrintable

Details

    • Hide

      -Set up httpd/mod_cluster as usual with 2 JBoss nodes behind it.
      -Set sticky-session-remove to true on JBoss:

                  <mod-cluster-config advertise-socket="modcluster" proxy-list="127.0.0.1:6666" connector="ajp" sticky-session-remove="true">

      -Confirm node1 is reached via sticky sessions:

      curl localhost/yourapp\;jsessionid=tesing.node1

      -Kill node1 and attempt the same request again:

      kill -9 <node1_pid>
curl localhost/yourapp\;jsessionid=tesing.node1

      This should cause the request to failover to node2, resulting in remove_session_route's execution and the problem loop.

      Show
      -Set up httpd/mod_cluster as usual with 2 JBoss nodes behind it. -Set sticky-session-remove to true on JBoss: <mod-cluster-config advertise-socket= "modcluster" proxy-list= "127.0.0.1:6666" connector= "ajp" sticky-session-remove= " true " > -Confirm node1 is reached via sticky sessions: curl localhost/yourapp\;jsessionid=tesing.node1 -Kill node1 and attempt the same request again: kill -9 <node1_pid> curl localhost/yourapp\;jsessionid=tesing.node1 This should cause the request to failover to node2, resulting in remove_session_route's execution and the problem loop.
    • Workaround Exists
    • Hide

      -Use sticky-session-remove="false" in the JBoss mod-cluster-config (the default)

      Show
      -Use sticky-session-remove="false" in the JBoss mod-cluster-config (the default)
    • Low

    Description

      remove_session_route causes an infinite loop when parsing jsessionid out of URLs. The stack of the looping thread is:

      #0  0x00007f4cf2b66e45 in remove_session_route () from /etc/httpd/modules/mod_proxy_cluster.so
#1  0x00007f4cf2b68ad9 in ?? () from /etc/httpd/modules/mod_proxy_cluster.so
#2  0x00007f4cf2f7d116 in proxy_run_pre_request () from /etc/httpd/modules/mod_proxy.so
#3  0x00007f4cf2f84186 in ap_proxy_pre_request () from /etc/httpd/modules/mod_proxy.so
#4  0x00007f4cf2f813c2 in ?? () from /etc/httpd/modules/mod_proxy.so
#5  0x00007f4cf776df70 in ap_run_handler ()
#6  0x00007f4cf777180e in ap_invoke_handler ()
#7  0x00007f4cf777cfd0 in ap_process_request ()
#8  0x00007f4cf7779d48 in ?? ()
#9  0x00007f4cf7775a58 in ap_run_process_connection ()
#10 0x00007f4cf7781fa7 in ?? ()
#11 0x00007f4cf77822ca in ?? ()
#12 0x00007f4cf7782f4c in ap_mpm_run ()
#13 0x00007f4cf7759ab5 in main ()

      That is looping here:

      mod_proxy_cluster.c
                      while (*path !='&' || *path !='\0')
                    path++;

      "*path !='&' || *path !='\0'" is a tautology so the while never ends. It should be an && instead of ||.

      Attachments

        Issue Links

          duplicates

          Bug - A problem that impairs or prevents the functions of the product. MODCLUSTER-373 [mod_cluster] - mod_proxy_cluster.c:3325: possible bad if test ?‏

          • Major - To be worked after higher priority work items are addressed. When the severity is high and the effort to change it is low to moderate, this term is chosen. Issues in this category likely have an existing workaround but implementation or execution may be non-trivial.
          • Closed

          Activity

            People

              rhn-engineering-jclere Jean-Frederic Clere
              rhn-support-aogburn Aaron Ogburn
              Votes:
              0 Vote for this issue
              Watchers:
              1 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: