Eclipse

1. Eclipse workspace is not opening/ WorkSpace not opening/
First thing to try is "./eclipse -clean" for example @ eclipse-platform-3.4.1-win32\eclipse>eclipse -clean
Second option could be deleting “.snap” in the folder “org.eclipse.core.resources” at workspace\.metadata\.plugins\org.eclipse.core.resources\
The last and final solution is to remove ".metadata" folder from workspace. This has side effects you again need to set all the build paths and projects in the Preferences and build path of each project which could be tedious task.

DB2 Performance

Performance of Java Application

1. Issue and its resolution
ISSUE 1
Aug 19, 2013 3:14:36 PM org.apache.coyote.AbstractProtocol init
SEVERE: Failed to initialize end point associated with ProtocolHandler ["http-bio-8081"]
java.net.BindException: Address already in use <null>:8082    at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:406)
    at org.apache.tomcat.util.net.AbstractEndpoint.init(AbstractEndpoint.java:610)
    at org.apache.coyote.AbstractProtocol.init(AbstractProtocol.java:429)
    at org.apache.coyote.http11.AbstractHttp11JsseProtocol.init(AbstractHttp11JsseProtocol.java:119)
    at org.apache.catalina.connector.Connector.initInternal(Connector.java:981)
    at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
    at org.apache.catalina.core.StandardService.initInternal(StandardService.java:559)
    at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
    at org.apache.catalina.core.StandardServer.initInternal(StandardServer.java:814)
    at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
    at org.apache.catalina.startup.Catalina.load(Catalina.java:640)
    at org.apache.catalina.startup.Catalina.load(Catalina.java:665)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:281)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: java.net.BindException: Address already in use

Resolution:- Find the process running and then kill it. 
Command: ps -ef  | grep java or ps -ef  | grep tomcat
Sample out put: 
[root@XXXXXXXX ]# ps -ef|grep java

root 3429 1 0 Aug16 ? 00:11:06 /opt/jdk1.7/jdk1.7.0_25/bin/java -Djava.util.logging.config.file=/opt/tomcat-instance3/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/opt/apache-tomcat-7.0.42/endorsed -classpath /opt/apache-tomcat-7.0.42/bin/bootstrap.jar:/opt/apache-tomcat-7.0.42/bin/tomcat-juli.jar -Dcatalina.base=/opt/tomcat-instance3 -Dcatalina.home=/opt/apache-tomcat-7.0.42 -Djava.io.tmpdir=/opt/tomcat-instance3/temp org.apache.catalina.startup.Bootstrap start
root 3462 1 0 Aug16 ? 00:10:56 /opt/jdk1.7/jdk1.7.0_25/bin/java -Djava.util.logging.config.file=/opt/tomcat-instance4/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/opt/apache-tomcat-7.0.42/endorsed -classpath /opt/apache-tomcat-7.0.42/bin/bootstrap.jar:/opt/apache-tomcat-7.0.42/bin/tomcat-juli.jar -Dcatalina.base=/opt/tomcat-instance4 -Dcatalina.home=/opt/apache-tomcat-7.0.42 -Djava.io.tmpdir=/opt/tomcat-instance4/temp org.apache.catalina.startup.Bootstrap start
root 18158 1 1 15:14 pts/1 00:00:08 /opt/jdk1.7/jdk1.7.0_25/bin/java -Djava.util.logging.config.file=/opt/tomcat-instance1/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/opt/apache-tomcat-7.0.42/endorsed -classpath /opt/apache-tomcat-7.0.42/bin/bootstrap.jar:/opt/apache-tomcat-7.0.42/bin/tomcat-juli.jar -Dcatalina.base=/opt/tomcat-instance1 -Dcatalina.home=/opt/apache-tomcat-7.0.42 -Djava.io.tmpdir=/opt/tomcat-instance1/temp org.apache.catalina.startup.Bootstrap start
root 19470 1 28 15:23 pts/1 00:00:09 /opt/jdk1.7/jdk1.7.0_25/bin/java -Djava.util.logging.config.file=/opt/tomcat-instance2/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/opt/apache-tomcat-7.0.42/endorsed -classpath /opt/apache-tomcat-7.0.42/bin/bootstrap.jar:/opt/apache-tomcat-7.0.42/bin/tomcat-juli.jar -Dcatalina.base=/opt/tomcat-instance2 -Dcatalina.home=/opt/apache-tomcat-7.0.42 -Djava.io.tmpdir=/opt/tomcat-instance2/temp org.apache.catalina.startup.Bootstrap start
root 19524 7328 0 15:24 pts/1 00:00:00 grep java


Identify the process which is giving the above error Kill the process using it's PID
[root@blrpslliqperf1 jrconf]# kill -9 3429 
Note:- I have 4 tomcats running and I am trying to kill the one which gave me bind error.

WebSphere 7.0.0.7/7.0.0.13

1. SystemOutLogs--- we can configure the log file size because it over writes the files at log location, to change conf go to Troubleshooting>>Logs and trace>>"Server">>JVM Log

2. Multi-JVM/Clustering-- The number of servers in the cluster = the numberof JVMs, unless you are using Z/OS. Sometime we use the term multi JVM for Clustering which is confusing.

3. Clustering is of two types.

a. Horizontal Clustering:-where we need seperate machines for each server/node in the clustering environment.

b. Verticle Clustering:- where in the same machine multiple servers/nodes are present, we don't need seperate machines. In websphere this can be done by having different profiles and in JBoss it can be achieved by making unique ports(RMIPort,RMIObjectPort,ServerBindPort,JBoss/Tomcat Http ports,ServerBindPort,WebService,Naming Port) in jboss-service.xml accross the cluster environment.

Note:- The advantage of Multiple JVM is applicable in both horizontal as well as Vertical clustering.

Note:- What is the meaning of 3 nodes 5 JVM? This is 3 machines in which 2 servers have 2 profiles each running in two seperate machine and 1 server with 1 profile running in the third machine, by this I have 5 servers running in 5 JVM and its 3 node 5 JVMs.