My Technical Blog

      VisualVM can be very helpful to discover the performance lags in Java application.  It is one of the easiest profiling tools for Java. Download VisualVM https://visualvm.github.io/ Run VisualVM and check local running java apps:  Remote Profiling. Run your java application with following JVM arguments: - Djavax . management . builder . initial = - Dcom . sun . management . jmxremote - Dcom . sun . management . jmxremote . port = 9010 - Dcom . sun . management . jmxremote . local . only = false - Dcom . sun . management . jmxremote . authenticate = false - Dcom . sun . management . jmxremote . ssl = false Above parameters, makes your remote java application to listen to port 9010. Then, you can connect to it from VisualVM by Menu->File->Add JMX connection Type your hostname and port. Example: 192.168.10.10:9010 (IP address of remote machine and port) Performance Profiling       After you connect to your app from VisualVM, go to " Sampler "

Install Tsung on CentOS Pre-requisites: 1. Install Erlang: sudo   yum -y update &&  sudo   yum -y upgrade sudo   yum  install   epel-release sudo yum -y install erlang perl perl-RRD-Simple.noarch perl-Log-Log4perl-RRDs.noarch gnuplot perl-Template-Toolkit 2. Get Tsung wget http://tsung.erlang-projects.org/dist/tsung-1.6.0.tar.gz 3. Extract and Install tar zxvf tsung-1.6.0.tar.gz cd tsung-1.6.0 ./configure && make && sudo make install Note: Sample XML configurations are located in  /usr/share/doc/tsung/examples/http_simple .xml Setup up Cluster Testing with Tsung 1. Add cluster nodes info in each node's "/etc/hosts" sudo vi /etc/hosts # cluster nodes 192.168.10.10       n1 192.168.10.11       n2 192.168.10.12       n3 192.168.10.13       n4 2. Setup ~/.ssh/config file vi ~/. ssh /config Host n1    Hostname n1    User tsung    Port 722    IdentityFile /home/tsung/ . ssh /my_key_rsa7 Host n2