Why a newer JRE is important
AppMon installations (Server, Collector, Client,...) are shipped with an Oracle Java 8 JRE. We always use the most recent JRE version for AppMon releases to guarantee a stable and reliable deployment. Over time, the JRE version that ships with AppMon may become outdated. This is of concern because new JRE releases typically contain security updates and bugfixes. Thus, it makes sense to keep the JRE updated to avoid security vulnerabilities and other known problems. This article describes:
When you install Dynatrace AppMon you get the following JREs on Windows and Linux:
For collectors running on other platforms, we don't ship a JRE. The JRE must be provided by the customer. This article focuses on how to update the shipped JREs.
Which JREs are supported
Until now, AppMon only supported the Oracle JREs. Starting with OpenJDK Update 192, we now also support OpenJDK. This is important as OpenJDK 8 will ship security updates longer for Java 8 than Oracle will.
For AppMon 7.1, Dynatrace offers recent OpenJDK builds that provide you with a recent Java runtime, including security fixes. The OpenJDK builds are provided as zip archives that have to be manually deployed. You can find them here: https://downloads.dynatrace.com/downloads/download.aspx?p=1&r=205 (section"Java Updates")
So we support all JREs that we offer there, no other JREs are supported.
Starting with AppMon 7.2, Dynatrace offers JRE update packs that provide you with a recent Java runtime, including security fixes. There is no option to deploy a custom runtime. The JRE update packs can be found here: https://downloads.dynatrace.com/downloads/download.aspx?p=1&r=219 (section "Java Updates")
So we support all JREs that we offer through our JRE update packs. No other JREs are supported. In practice we provide:
(currently) Oracle Java 8 Update 181 with the installer
(currently) JRE Update Packs with the latest OpenJDK 8 update (OpenJDK Update 192 is the first we offer)
(in the future) We plan to switch AppMon 7.2 to OpenJDK 11 in a coming release. From that point on we will ship the latest OpenJDK 11 update
How to update the JRE
Note: In 7.1 we support 32bit collectors but we don't offer 32bit VMs as download. If you are using a 32bit collector and want to update to a newer JRE you can download a recent OpenJDK build from an external source and exchange the jre directory within the collector installation directory.
To upgrade the runtime of any AppMon installation, please follow these steps (these steps must be performed for any AppMon Installation type: Full, Server, Collector or Client install):
1. Download and extract a recent Java Update to a temporary directory on the target machine. The Java Update can be downloaded here: https://downloads.dynatrace.com/downloads/download.aspx?p=1&r=205 (section"Java Updates"). We will refer to this directory as <TEMP_DIR>
Windows: e.g. Extract downloaded zip archive to "C:\temp"
Linux: e.g. Extract downloaded zip archive to "/home/user/tmp"
2. Shut down the components where you want to update the JRE
3. Rename directory <DT_INSTALL_DIR>/jre to <DT_INSTALL_DIR>/jre.orig
<DT_INSTALL_DIR> is the location of the AppMon installation
Windows: e.g. Rename directory "C:\%program_files%\dynaTrace\dynaTrace 7.1\jre" to "C:\%program_files%\dynaTrace\dynaTrace 7.1\jre.orig"
Linux: e.g.Rename directory "/opt/dynatrace-7.1/jre" to "/opt/dynatrace-7.1/jre.orig"
4. Copy the directory <TEMP_DIR>/jre-1.8.0_xxx to <DT_INSTALL_DIR>
Windows: e.g. Copy directory "C:\temp\jdk-1.8.0_202-windows-x86-64\jre1.8.0_202" to folder "C:\%program_files%\dynaTrace\dynaTrace 7.1"
Linux: e.g. Copy directory "/home/user/tmp/jdk-1.8.0_202-linux-x86-64/jre1.8.0_202" to directory "/opt/dynatrace-7.1"
5. Rename the newly copied "jre-1.8.0_xxx" directory in <DT_INSTALL_DIR> to "jre"
Windows: e.g. Rename directory "C:\%program_files%\dynaTrace\dynaTrace 7.1\jre1.8.0_202" to "C:\%program_files%\dynaTrace\dynaTrace 7.1\jre"
Linux: e.g. Rename directory "/opt/dynatrace-7.1/jre1.8.0_202" to "/opt/dynatrace-7.1/jre"
6. Startup the affected components and check if everything starts as expected
7. If everything is running fine, delete the backup directory created in step 3. In case of any problems delete the directory <DT_INSTALL_DIR>/jre and rename <DT_INSTALL_DIR>/jre.orig to <DT_INSTALL_DIR>/jre
As already mentioned we have a new approach to shipping Java updates to AppMon 7.2 customers.
Right now we offer new Java updates as a separate download item on our download page. They can be found here in section "JRE Updates": https://downloads.dynatrace.com/downloads/download.aspx?p=DT
The downloaded file can be installed with the Dynatrace AppMon Client. It is automatically distributed to all components. A detailed description can be found in the AppMon documentation (https://www.dynatrace.com/support/doc/appmon/installation/product-updates/jre-update/). Please have a look at the section "Manual Installation".
In the future, the Dynatrace AppMon Client will actively notify you when new Java Updates are available.