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Note that this content is currently under review.

You apply patches to WSO2 products either as individual patches or through a service pack. A service pack is recommended when the number of patches increase. The following sections explain the WSO2 patch application process:


Before you begin

  • You can download all WSO2 Carbon Kernel patches from here.
  • Before you apply a patch, check its README.txt file for any configuration changes required.

WSO2 has introduced the WSO2 Update Manger (WUM), which is a command-line tool that allows you to update your product with the latest available patches and enhancements. You can see if your product version is supported by WUM from here, and if it is supported, follow the instructions in Updating your WSO2 product to get the latest patches. 

The patch application process described below guides you on how to manually apply security patches to Carbon 4.4.x-based products (if your product version is currently not supported by WUM). 

Table of Contents

Applying service packs to the product

A service pack is a collection of patches in a single pack. It contains two elements:

  • The lib directory: contains  contains all the JARs relevant to the service pack.
  • The servicepack_patches.txt text file: contains the list of JARs in the service pack.


  1. Copy the service pack file to the <PRODUCT_HOME>/repository/components/servicepacks/ directory. For example, the image below shows how a new service pack named servicepack001 is added to this directory. 
    The servicepacks directory with the new servicepack001 subdirectory, which contains servicepack_patches.txt and the lib subdirectory with the patch JAR files.
  2. Start your product. The following steps will be executed:
    1. Before applying any patches, the process first creates a backup folder named patch0000 inside the <PRODUCT_HOME>/repository/components/patches/ directory, which will contain the original content of the <PRODUCT_HOME>/repository/components/plugins/ directory. This step enables you to revert back to the previous state if something goes wrong during operations.

    2. The latest service pack in the <PRODUCT_HOME>/repository/components/servicepacks/ directory will be applied. That is, the patches in the service pack will be applied to the <PRODUCT_HOME>/repository/components/plugins/ directory.
    3. In addition to the service pack, if there are individual patches added to the <PRODUCT_HOME>/repository/components/patches/ directory, those will also be incrementally applied to the plugins directory. 


      The metadata file available in the service pack will maintain a list of the applied patches by service pack. Therefore, the metadata file information will be compared against the <PRODUCT_HOME>/repository/components/patches/ directory, and only the patches that were not applied by the service pack will be incrementally applied to the plugins directory. 



Prior to Carbon 4.2.0 version, users were expected to apply patches by starting the server with -DapplyPatches. Now, you do not have to issue a special command to trigger the patch application process. It starts automatically if there are changes in either the  <PRODUCT_HOME>/repository/components/servicepacks/ directory or the <PRODUCT_HOME>/repository/components/patches/ directory. It verifies all the latest JARs in the servicepacks and patches directories against the JARs in the plugins directory by comparing MD5s of JARs.


  • All patch related logs are recorded in the <PRODUCT_HOME>/repository/logs/patches.log file.
  • The <PRODUCT_HOME>/repository/components/patches/.metadata/prePatchedJARs.txt meta file contains the list of patched JARs and the md5 values.
  • A list The patch directory information of all the applied service packs and patches are patched will be in the <PRODUCT_HOME>/repository/components/default/configuration/prePatchedprePatchedDir.txt file.


    Do not change the data in the <PRODUCT_HOME>/repository/components/default/configuration/prePatchedprePatchedDir.txt file. The patch application process gets the pre-patched list from this file and compares the list with the patches available in the servicepack and patches directories. If you change the data in this file, you will get a startup error when applying patches.