LAKSHMI WEBLOGIC/SOA ADMIN

Understanding garbage collection It uses for a free memory occupied by objects that are no longer being used by the application. The Java Language Specification (JLS) does not require a JVM to have a garbage collector.All of the commonly used JVMs have garbage collectors, and most garbage collectors use similar algorithms to manage their memory and perform collection operations. we need to understand how the JVM performs garbage collection so that we can identify the tuning . The garbage collection algorithms and implementations, it is possible to tune the application and gc behaviour to max its  performance.  Garbage collectors will identify an object is eligible for collection by objects are being referenced by any active objects in the system tor not. They are garbage tho general approaches for this are : Reference counting  Object reference traversal  We have  Some garbage collectors used by modern JVMs are: Mark-and-sweep coll...

 For Setting a Class Path WL-Home\servers\bin SetwlsEnv.cmd (windows) WL-Home\servers\bin SetwlsEnv.sh (Unix) For Setting a set Domain WL-Home\servers\bin SetDomainEnv.cmd(win) WL-Home\servers\bin SetDomainEnv.sh(Unix) To increase WLS Memory  set minimum and maximum to same size $ Java ...-ms32m -mx32m      -> it will allocate 32 megabytes.             :Xms2048m - Xmx2048m  Increase Permgenspace -XX :Maxpermsize=256m (default =64m). To Enable verboseGC Java_Options = -"Xverbose:Memory,gcreport,gcpause-xverbosetimestamp" Enable core dump sun JVM;  -xx:+ShowMessageBoxOnError Jrockit JVM: -Djrockit.WaitOnError Windows : DrWatson Server is listening on the specified port number or not telnet <IP> <Port> Ex: telnet 199.129.212.1 8080 To check server is alive or not Ping <IP> Ex: Ping 199.129.212.1 start Managed Server Independence Mode? ...

Web Logic Server performance tuning ranges over an extremely broad area and includes the tuning of  Operating system Tuning (CPU and Native IO) JVM Tuning (Heap and GC tuning) Weblogic server Tuning ( Cluster,Thread pools and stuck threads) Workmangers Tuning. (Define workmangers) Java DataBase Tuning (Connection Pools ,Data sources,Transactions ) JMS Tuning Application Tuning and Web services Tuning (Servelets, JSP's) Setting Java Parameters for Starting WebLogic Server The important performance tuning parameters in these files are the  JAVA_HOME  parameter and the Java heap size parameters:  Change the value of the variable  JAVA_HOME  to the location of your  JDK . For example: set JAVA_HOME=C:\bea\jdk150_03   For higher performance throughput, set the minimum java heap size equal to the maximum heap size. For example: "%JAVA_HOME%\bin\java" -server – Xms512m – Xmx512m -classpath %CLASSPATH% -   Work Managers and Execute...

WebLogic 12c (12.1.2) is the latest version released. It is robust, provides unmatched performance and high availability. This can be downloaded from the below URL. http://www.oracle.com/technetwork/middleware/fusion-middleware/downloads/index.html Below are few new features that are introduced in WebLogic 12.1.2. 1. Dynamic Cluster Support: It is one of the most striking features of WebLogic 12.1.2. This release introduces use of the dynamic cluster for a highly scalable systems, high availability environment.  Dynamic cluster allows the managed servers to be automatically added based on a server template. 2. Support with Oracle Database 12c. This release of WebLogic Server adds support for Oracle Database 12c 3. JMS enhancements: Supports clustered targeted JMS Servers for providing high availability  eliminating the need to configure many JMS resources for every single server. 4. Enhanced maven support. Support for POMs, Maven 3.0.4. 5. WebSocket s...

JVM(Java Virtual Machine) JVM Architecture:  JVM is the heart of any Java based Application Server. We face most of the issues due to incorrect JVM tuning. It is very important to understand the Overall architecture of the JVM in order to trouble shoot different JVM tuning related issues. Here we are going to discuss the Architecture and the Major parts of a Java Process And the Java Heap Division. The Following Diagram is just a basic overview of a Java Process in a 2 GB process Size Machine. Usually in 32 bit Windows Operating Systems the default process size will be 2 GB (In Unix based 64 bit operating Systems it can be 4GB or more). So i draw the following Diagram of Java Process to explain the Java Process partitions in a 2Gb process size machine. Java Process Architecture Diagram In the above diagram we will find different partitions of a Java Process. Please compare the above diagram with below descriptions. . 1)  Just for Example we can see that Proc...