Solving memory problems in Web. Sphere applications. Jing Sun and James Tang. Innovative software testing solutions tools and services for automated and manual testing of application software, Web sites, middleware, and system software. Published on June 2. Updated August 2. Firemin-Options.jpg' alt='Memory Leak Testing Tool Windows Adb' title='Memory Leak Testing Tool Windows Adb' />Memory Leak Testing Tool Windows Only RootVirtual memory ballooning is a primarily VMware memory management technique that lets the host server reallocate spare VM memory to where it is most needed. But it. lsass. ese memory leak on Windows 2008 Standard R2 x64, not Domain Controller. In computer science, a memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in such a way that memory. Learn how to identify root causes for and solve memory problems in WebSphere Commerce during system test. In Web applications based on Web. Sphere Application Server, memory. One of the most. common memory problems is memory leak, which causes severe performance. In theory, memory leaks should not happen in Java. Garbage Collection GC. However, GC only cleans up unused. Therefore, if an object is not. GC does not remove it, which leads to. JVM problems. Beside memory leaks, other memory problems. In many cases, these memory problems can cause the. Many users first notice that application. Out. Of. Memory exceptions. Memory problems are hard to troubleshoot because they have multiple causes. This article provides methods of identifying the root causes of different. It also introduces a. Web. Sphere Commerce V6. This guide is available to download as a free PDF. Download How to Troubleshoot Low RAM or Memory Leaks in Windows now. Feel free to copy and share this with your. Windows Server 2012 STD 32GB RAM SQL 2008 STD Server running. MAX ram reserved 18GB HyperV installed, runs 1 virtual guest Windows 2012, MAX ram 4GB I. ISTQB Exam Questions on Equivalence partitioning and Boundary Value Analysis. Its important that all testers should be able to write test cases based on Equivalence. PDF files that contain the Visual Studio 2005 documentation. General purpose, language independent. The following tools work based on log files that can be generated from various systems. TimeToPic visualizes a log file. Web. Sphere Commerce is one of the largest J2. EE applications. deployed on Web. Sphere Application Server. This methodology detects and. Web. Sphere Commerce during system test. Method. overview. Deliver new web apps fast Try building and deploying your next project on the IBM Bluemix cloud platform, where you can take advantage of. Sign up for a free. Figure 1 shows the whole process for determining and solving memory. There are five kinds of solution listed in this diagram, which. Memory Leak Testing Tool Windows 7Tuning the max heap. Tuning XkXp. Identifying by swprofiler. Tuning the cache size. Performing the heap dump. Figure 1. Process diagram for memory. View image at full size. Setting verbose. Garbage Collection to get Web. Sphere Application Server logs for memory. To analyze memory problems in the application server, the first step is to. GC information. You need a tool to analyze this information. Setting verbose GC to. Web. Sphere Application Server logs for memory monitor. To monitor the usage of JVM memory, get verbose garbage collection GC. Web. Sphere Application Server that is. Web. Sphere Application Server Installation. The default setting of. Web. Sphere Application Server does not enable this, but you can enable it. Web. Sphere Application Server v. Open the Web. Sphere Application Server administration site by typing. The port is the number. HTTP administrative port, which is 9. Type an ID. any ID without a password and log in to it. Select Servers Application servers server. Java. and Process Management Process Definition Java Virtual. Machine. Select Verbose garbage collection as shown in Figure. Click Apply and click Save at the. Restart Web. Sphere Application Server. Figure 2. Enable verbose GC in. Web. Sphere Application Server V6. View image at full size. After restarting Web. Sphere Application Server, you see the verbose GC. Analyzing verbose. GCThere are many tools for verbose GC log analysis, such as Tivoli. Performance Viewer, Dump JVM DMPJVM, and Web. Spheres Resource Analyzer. These tools can abstract useful information, and illustrate the trend of. JVM heap size usage over time. After you analyze your nativestdout. Occupancy MBAllocation Rate KBsecTotal GC pause time msMark and Sweep Time msCompact Time msGC Cycle length and distribution msFree Space after GC MBFree Space before AF allocation failure MBSize of Request that caused AF BytesAmong these charts, some are helpful in monitoring the effects of GC and. You can use GC Cycle length and distribution to. GC frequency and distribution, Free Space after GC to analyze. Free Space before AF and Size of Request that caused. AF to analyze fragmentation or large objects. Other charts can also. Figures 3 and 4 show some examples of Free Space after GC. In a normal. Free Space after GC graph, where the application is using the. Java heap properly, the red line should be approximately on a. Figure 3. In Figure 4, the declining red line means. If you suspect a. Out. Of. Memory exception. This helps you to get better support from Web. Sphere. Application Server and the JDK if the problem is related to Web. Sphere. Application Server or the JDK. Figure 3. Example of normal Free Space. GC chart. View image at full size. Figure 4. Example of Free Space after. GC chart with problem. View image at full size. Analyzing. fragmentation. If there is a memory problem, but no reduction in free space after GC. Free Space Before AF and Size of Request that. AF. AF means that an object needs heap space, but there is not. JVM heap for it. Generally, AF. JVM heap is used up. However, AF also occurs if all the. This problem is greatly magnified if there are large object. Free Space. before AF means the size of free space when AF occurs. This space should. AF occurs. Therefore, the red line is always near the bottom of the chart. Figure 5. shows normal usage without fragmentation problems. Severe fragmentation causes frequent GC cycles, and thus performance. Rising GC frequency is another indicator of. Figure 5. Normal Free Space before AF. View image at full size. Tuning the max heap. If the free space after GC does not decline, check the GC cycle length and. GC pause time. If the time since the last AF. Win32_Systemenclosure Serial Number. GC cycle length and distribution is not too small, but the complete. Total GC Pause Time is high, it means that GC is not very. GC duration is very high. The duration of each GC cycle. In this situation, the heap is probably too. GC takes a long time to clean up objects in. In the other cases where. GC frequency is too high, the heap is probably too small for the. GC needs to run frequently, so increase the maximum heap. Solution. To tune the JVM Max Heap size Open the Web. Sphere Application Server administrative console. Expand Servers Application servers server. Java. and Process Management Process Definition Java Virtual. Machine. Change the Max Heap Size to a larger value. Click Apply and click Save at the. Restart Web. Sphere Application Server. Try your test case again and see if the problem disappears. Note that i. 5OS should have no maximum heap size according to the. System i Tuning Guide because the allocation model is. After it is set to unlimited, it may take. GB. Tuning. XkXp. If the free space after GC does not decline, but the time since the last AF. GC cycle length and distribution is always small, there might be. You can try to tune the XkXp. Solution. The solution is to group immovable objects together into pools so that they. Java heap. In Java SDK 1. GC allocates a. k. Cluster as the first object at the bottom of the heap. A k. Cluster is an. The GC then. allocates a p. Cluster as the second object on the heap. A p. Cluster is an. When the. default k. Cluster size is not sufficient to allocate all class blocks, you. Xk and Xp options to specify k. Cluster and p. Cluster sizes. GC trace provides a guide for optimum Xk and Xp values in version 1. You can launch this command by typing. Dibm. dg. trc. printstverify in the Generic JVM. Web. Sphere Application Server administrative. After you save the change and rerun the testcase, you can find. GCVFY SUM pinned4. The pinned and classes sizes are about the right size needed for the Xk. Adding 1. 0 to the reported value 3. The difference between pinned 4. Cluster. You can specify the p. Cluster and p. Cluster overflow sizes using. Xp command line option XpiiiiK,ooooKiiii specifies the size of the initial p. Cluster in KB, and. Clusters in KB. Default values are 1. KB for iiii and 2 KB for oooo. Figure 6 is an example of setting Xk and Xp, which specifies. Xk. 22. 00. 0 Xp. Generic JVM arguments. If the problem. persists, experiment with higher initial p.