This documentation is for WSO2 Carbon 4.4.0. View documentation for the latest release.
Page Comparison - Performance Tuning (v.5 vs v.8) - Carbon 4.4.0 - WSO2 Documentation
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  • Performance tuning requires you to modify important system files, which affect all programs running on the server. We recommend you to familiarize yourself with these files using Unix/Linux documentation before editing them.
  • The parameter values we discuss below are just examples. They might not be the optimal values for the specific hardware configurations in your environment. We recommend that you carry out load tests on your environment to tune the product accordingly.




  1. To optimize network and OS performance, configure the following settings in /etc/sysctl.conf file of Linux. These settings specify a larger port range, a more effective TCP connection timeout value, and a number of other important parameters at the OS-level.

    Code Block
    net.ipv4.tcp_fin_timeout = 30
    fs.file-max = 2097152
    net.ipv4.tcp_tw_recycle = 1
    net.ipv4.tcp_tw_reuse = 1
    net.core.rmem_default = 524288
    net.core.wmem_default = 524288
    net.core.rmem_max = 67108864
    net.core.wmem_max = 67108864
    net.ipv4.tcp_rmem = 4096 87380 16777216
    net.ipv4.tcp_wmem = 4096 65536 16777216
    net.ipv4.ip_local_port_range = 1024 65535      

    When we have the localhost port range configuration lower bound to 1024, there is a possibility that some processes may pick the ports which are already used by WSO2 servers. Therefore, it's good to increase the lower bound as sufficient for production, e.g., 10,000.

  2. To alter the number of allowed open files for system users, configure the following settings in the /etc/security/limits.conf file of Linux.

    Code Block
    * soft nofile 4096
    * hard nofile 65535

    Optimal values for these parameters depend on the environment.

  3. To alter the maximum number of processes your user is allowed to run at a given time, configure the following settings in the  /etc/security/limits.conf file of Linux (be sure to include the leading * character). Each carbon server instance you run would require upto 1024 threads (with default thread pool configuration). Therefore, you need to increase the nproc value by 1024 per each server (both hard and soft).

    Code Block
    * soft nproc 20000
    * hard nproc 20000




If one or more worker nodes in a clustered deployment require access to the management console, you need to increase the entity expansion limit in the <PRODUCT_HOME>/bin/wso2server.bat file (for windows) or the <PRODUCT_HOME>/bin/ file (for Linux/Solaris) as show below. The default entity expansion limit is 64000.

Code Block



pool configuration

Within the WSO2 platform, we use Tomcat JDBC pooling as the default pooling framework due to its production ready stability and high performance. The goal of tuning the pool properties is to maintain a pool that is large enough to handle peak load without unnecessarily utilising resources. These pooling configurations can be tuned for your production server in general in the <PRODUCT_HOME>/repository/conf/datasources/master-datasources.xml file.



When it comes to web applications, users are free to experiment and package their own pooling framework such BoneCP.

Caching configuration

The <Cache> element configured in the carbon.xml file (stored in the <PRODUCT_HOME>/repository/conf directory) sets the global caching timeout in minutes for your server. This value specifies the time period after which, the cache will refresh. If the components in your product do not have specific caching timeout values configured, the global caching timeout will be applicable by default. Be sure to restart the server if you change the default caching timeout in the carbon.xml file shown below. 

Code Block
    <!-- Default cache timeout in minutes -->

Setting the thread execution limit


The Carbon runtime limits the thread execution time. That is, if a thread is stuck or taking a long time to process, Carbon detects such threads, interrupts and stops them. Note that Carbon prints the current stack trace before interrupting the thread. This mechanism is implemented as an Apache Tomcat valve. Therefore, it should be configured in the <PRODUCT_HOME>/repository/conf/tomcat/catalina-server.xml file as shown below.


  • The className is the Java class name used for the implementation. This must be set to org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve.
  • The threshold gives the minimum duration in seconds after which a thread is considered stuck. Default value is 600 seconds.

This configuration works only for the servlet transport.