Uploaded image for project: 'JBoss Enterprise Application Platform 4 and 5'
  1. JBoss Enterprise Application Platform 4 and 5
  2. JBPAPP-2128

JGroups ConnectionTable Can Have Spurious Connection Instances On Concurrent Connects

    XMLWordPrintable

Details

    • Support Patch
    • Resolution: Done
    • Major
    • One Off Releases
    • 4.3.0.GA_CP04
    • Clustering
    • None
    • JGroups_2_4_5_GA_JGRP_549
    • Hide
      PATCH NAME:
              JBPAPP-2128
      PRODUCT NAME:
              JBoss Application Server/Platform
      VERSION:
              4.3 CP04
      SHORT DESCRIPTION:
              JGroups ConnectionTable Can Have Spurious Connection Instances On Concurrent Connects
      LONG DESCRIPTION:
              JGroups ConnectionTable can have spurious Connection instances on concurrent connects which can result in continuous QueueClosedExceptions as well as cause clusters to not heal after being split.
      MANUAL INSTALL INSTRUCTIONS:
              Rename %JBOSS_HOME%/server/all/lib/jgroups.jar to "jgroups.replacedBy.JBPAPP-2128.jar.old"
              Copy the new jgroups.jar to %JBOSS_HOME%/server/all/lib/jgroups.jar

              Rename %JBOSS_HOME%/server/production/lib/jgroups.jar to "jgroups.replacedBy.JBPAPP-2128.jar.old"
              Copy the new jgroups.jar to %JBOSS_HOME%/server/production/lib/jgroups.jar

              Follow this same procedure for any custom server configuration/profile that needs this patch.
      COMPATIBILITY:
              N/A
      DEPENDENCIES:
              N/A
      SUPERSEDES:
              N/A
      SUPERSEDED BY:
              JBoss EAP 4.3 CP06
      CREATOR:
              Dennis Reed
      DATE:
              2009/06/20
      Show
      PATCH NAME:          JBPAPP-2128 PRODUCT NAME:         JBoss Application Server/Platform VERSION:         4.3 CP04 SHORT DESCRIPTION:         JGroups ConnectionTable Can Have Spurious Connection Instances On Concurrent Connects LONG DESCRIPTION:         JGroups ConnectionTable can have spurious Connection instances on concurrent connects which can result in continuous QueueClosedExceptions as well as cause clusters to not heal after being split. MANUAL INSTALL INSTRUCTIONS:         Rename %JBOSS_HOME%/server/all/lib/jgroups.jar to "jgroups.replacedBy. JBPAPP-2128 .jar.old"         Copy the new jgroups.jar to %JBOSS_HOME%/server/all/lib/jgroups.jar         Rename %JBOSS_HOME%/server/production/lib/jgroups.jar to "jgroups.replacedBy. JBPAPP-2128 .jar.old"         Copy the new jgroups.jar to %JBOSS_HOME%/server/production/lib/jgroups.jar         Follow this same procedure for any custom server configuration/profile that needs this patch. COMPATIBILITY:         N/A DEPENDENCIES:         N/A SUPERSEDES:         N/A SUPERSEDED BY:         JBoss EAP 4.3 CP06 CREATOR:         Dennis Reed DATE:         2009/06/20
    • Low

    Description

      If we have members A and B, and they don't yet have connections to each other, and start sending messages to each other at the exact same time, then we run into the following scenario:

      • A attempts to connect to B (new Socket())
      • B attempts to connect to A
      • A accepts B's connection and adds an entry for B into its table
      • B adds an entry for A into its table
      • B gets the accept() from A, but doesn't add the new Connection into its table because there is already a Connection. This leads to a spurious Connection object, which will only be closed and garbage collected once A or B leaves the cluster
      • We used to close Connections which were already in the table, but this lead to ping-pong effects where concurrent initial senders always closed each others connections
      • Even worse: a new Socket() always creates a new Connection object and places it into the table, regardless of whether a Connection for a given destination already exists or not !

      GOAL:
      #1 Have only 1 TCP connection between any 2 members
      #2 Establish a handshaking mechanism, to avoid spurious connections

      SOLUTION:

      • When A establishes a connection to B, A needs to get agreement from B first (and vice versa)

      Attachments

        1. jgroups.jar
          1.94 MB
        2. jgroups.jar
          1.94 MB
        3. jgroups.jar
          1.94 MB

        Issue Links

          is related to

          Bug - A problem that impairs or prevents the functions of the product. JGRP-549 ConnectionTable: spurious Connection instances on concurrent connects

          • 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.
          • Resolved
          relates to

          Sub-task - The sub-task of the issue JBPAPP-2130 JGroups ConnectionTable Can Have Spurious Connection Instances On Concurrent Connects

          • 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

              jbn-patch-team JBN Patch Team list
              rhn-support-jawilson Jimmy Wilson
              Votes:
              0 Vote for this issue
              Watchers:
              1 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: