Sizing the Java Virtual Machine for BlackBerry Collaboration Service

Article ID: KB34951

Type: Support Content

Last Modified: 02-18-2014


Product(s) Affected:

  • BlackBerry Enterprise IM for BlackBerry 10
Jump to: Environment | Overview
  • BlackBerry Enterprise Service 10 version 10.1 to 10.2
  • BlackBerry Collaboration Service 10.1 to 10.2.1

The BlackBerry Collaboration Service uses Java and depending on the number of users being serviced, requires changing the maximum amount of memory that is allowed to be used by the JVM heap. By default the BlackBerry Collaboration Service is sized to support 1000 users with a maximum Java heap memory limit of 2GB. If planning on supporting more than 1000 users per instance of BlackBerry Collaboration Service, it will be necessary to adjust the maximum allowed memory limits of the Java Virtual Machine based on the following recommendations:

Maximum Users

Suggested JVM Max Memory Heap Setting


4GB (4096M)


8GB (8192M)


10GB (10240M)

Note: Refer to the Installation and Administration Guide for hardware memory requirements regarding the BlackBerry Collaboration Service.

To change the allowed maximum Java Heap size perform the following steps:

  1. Open regedit on the BlackBerry Collaboration Service.
  2. Back up the registry:
    2. Click file > Export and choose the backup location.
  3. Expand HKLM > System > CurrentControlSet > Services
  4. Select BES-BlackBerry Collaboration Service
  5. Double-click ImagePath and scroll through the value data to find -Xmx2048M or -Xmx4096M.
  6. Adjust 2048M or 4096M to the suggested value according to the table above.
  7. Click OK.
  8. Restart the BlackBerry Collaboration service.


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