Java on Linux x86-64 supports 48-bit pointers and 256 TB of virtual address space, of which 128 terabytes is reserved for the Kernel , and 128 terabytes for User space.    Maximum Heap in  t heory on WAS Linux x86-64 would be -Xmx128t  with the caveat or requirement of having   -Xnocompressedrefs in place also, which essentially means Disabling Compressed References . Maximum Heap in practice on WAS Linux x86-64 would be approximately -Xmx76t for Java heap because the rest, or 52 TB, is used by Native heap .  *There is no Java heap size... [More]

Tags:  ibm-blog 64 largest linux bit xcompressedrefs xnocompressedrefs xmx 32 heap java maximum

      There are a few methods or ways to verify Configured Heap Values and monitor Current Heap Usage in WebSphere Application Server as well as a few different dump and file types useful for this task.   Useful Dumps and Files containing information about your Java Heap .   Javacores txt files are useful to determine Initial, Maximum and Current Heap values along with Threading and Locking information and even include a Native Memory usage section.  They are generally used to track Abends, Hangs, Out of Memory, GPF Crash, and Trace Assert type... [More]

Tags:  dumps xdump ibm-blog xms heapdump analyzer verbosegc heap mat system pmat xmx tdma javacore coredump javadump memory values gcmv java

   How and Where to increase the Maximum Heap for Application Deployment depends entirely upon whether you’re using the Admin Console , WSAdmin interface or EJBDeploy tool .   * Note that  when using the Default Gencon GC policy with  current WebSphere product releases such as v8.5.5.x & v9.x, we typically recommend both Initial and Maximum Heap values to be set to the same value. This setting avoids the additional configuration associated with resizing the heap to satisfy allocation requests and generally performs best in most... [More]

Tags:  admin ibm-blog heap ejbdeploy maximum deployment initial console application wsadmin

              End of Support Announcements: On September 30, 2016, IBM announced that WAS 7.0 and 8.0 will reach end of support on April 30, 2018. Additionally, the use of Java 6 with WAS 8.5.x will no longer be supported after April 30.  Note that Java 7 will be supported until July 2022 which is a change from the Sept. 30, 2019 announcement.  See IBM Blog at this   link .  Software withdrawal and service discontinuance: IBM WebSphere Application Server V7 and V8 and select IBM WebSphere products and part numbers - Some replacements available... [More]

Tags:  java java-6 discontinuance ibm-blog support was8.5 eos

      IBM Support content for IBM Business Process Manager (IBM BPM) V8.6 and IBM Case Manager V5.3.3 applies to IBM Business Automation Workflow. Business Automation Workflow combines IBM BPM and Case Manager into one workflow offering. It unites information, process, and users to provide a 360-degree view of work. In addition to process management and case management, Business Automation Workflow uses advanced analytics, business rules, and collaboration to drive more successful, optimized business outcomes. Learn more about... [More]

Tags:  ibm-blog

      Class loader synchronization bottlenecks are common problems brought to the attention of WebSphere Application Server L2 Support by our clients.  This is a common type of performance problem called a livelock where many threads are contending on a set of locks. The performance overhead is proportional to the lock contention, so the problem might not show up in a test environment with a low number of concurrent requests, or patterns of requests which aren't exercising the lock at the same time.  From the viewpoint of the application... [More]

Tags:  livelock syncronization class_loader classloader performance java ibm-blog

      This publication assumes the use of a currently supported DataPower firmware version at the time of posting.   Background DataPower offers the ability to configure both Static and Dynamic NFS mounts. For the purpose of this discussion, we will be assuming the use of the NFS Static Mount , as this is the most common and more widely seen in the field. An NFS Static Mount on DataPower mounts a directory from a remote file system to DataPower's to allow access for reading and writing files to the remote server. This not only can be used... [More]

Tags:  datapower health dp check nfs ibm-blog

      When you are monitoring connection pool performance, you may occasionally notice that connections are staying open for long periods of time. This behavior can have many different causes and can lead to issues like the connection pool maxing out. The J2CA0045E message is a good indication that your connection pool is maxed out: J2CA0045E: Connection not available while invoking method createOrWaitForConnection for resource jdbc/xxxxxx Some of the most common issues that can lead to connections staying open for longer than intended are the... [More]

Tags:  unshared websphere was j2c connections ibm-blog shared leak connection websphere_application_ser... pooling

      HELP!  I AM UNSUCCESSFUL IN CAPTURING THREAD DUMPS DURING A REQUIRED TIME-FRAME? You have lived the story before:  There is an intermittent delay in your IBM JVM application serving environment .  You contact support and they ask for the Performance MustGather collected DURING the time of the delay.  While the actual act of collecting the MustGather data is simple, since the delay is intermittent, you just can't seem to capture the MustGather data DURING the time of the performance issue.  No MustGather = No way to understand the... [More]

Tags:  javacore thread_dump ibm-blog healthcenter jhc

  WebSphere Profiles: For migrating WebSphere Application Server (WAS) itself (and its configuration), all the tools that you need already come with WAS V8.5.x . You would use WASPreUpgrade and WASPostUpgrade to migrate your WebSphere Profiles or you can opt to use the Migration Wizard graphical interface to those tools to help facilitate and automate the task for you. See the Migrating product configurations with migration tools section in the product documentation for more details.     Applications: There is also a handy Migration Toolkit... [More]

Tags:  application application_server was java websphere_application_ser... websphere migration ibm-blog server profile

  The WebSphere Application Server (WAS) JVM checks each of the following locations for existence and write-permission, and stores the Javadump, Heapdump, or System Coredump, in the first one available: The location specified by the IBM_JAVACOREDIR, IBM_HEAPDUMPDIR and IBM_COREDIR environment variables if set (_CEE_DMPTARG on z/OS). The current working directory of the JVM processes or $WAS_HOME/profiles/<ProfileName> dir. The location specified by the TMPDIR environment variable, if set. The /tmp directory or, on Microsoft Windows only,... [More]

Tags:  was tmpdir websphere application application_server cordir ibm-blog dump javacoredir heapdumpdir websphere_application_ser... server

    NOTE: Java SDK 6, going out of support, is embedded in WAS traditional V8.5 as the default Java SDK. Review details on tWAS: Support ends in April 2018. The end of Java SE 6: Where to go from here       Liberty: Support ends on September 2017 and that fix pack (17.0.0.3) will be compiled at the Java 7 level, so will not run. In this blog we will cover tWAS in detail.   Existing users updating from previous a fixpack continue to have embedded Java SDK 6 until Java SDK 6 goes End Of Support in April 2018. The next fixpack for 8.5.5.x shipped... [More]

Tags:  websphere_application_ser... java application application_server server was sdk websphere ibm-blog

  Javacores are generally not useful by themselves to analyze memory problems. However, javacores are still useful for providing hints on where memory may be accumulating by reviewing the NATIVEMEMINFO section.   Using 2 or more javacores from the same process ID (PID), compare the NATIVEMEMINFO sections from during the time frame when memory growth is noticed . The following example shows the NATIVEMEMINFO section from 2 javacores when it was noticed by the system administrator that the process size (not to be confused with the java heap size... [More]

Tags:  memory websphere_application_ser... javacore java ibm-blog websphere was calcavecchia nativememinfo noom native

  One of the most common questions asked in WebSphere Java support is, "What is the recommended Maximum Heap size?" One of the most common problems reported in WebSphere Java support is, "OutofMemory" condition (Java or Native).   This blog is simply a starting point or general reference based upon daily observations in the technical support arena, it is not intended to be a solution for every situation, but moreover a general set of starting recommendations. Ideally, you will need to test appropriate values in your own... [More]

Tags:  websphere out_of_memory was ibm-blog java oom heap heapsize websphere_application_ser...