Increase memory allocated to application deployed to payara micro - jvm

Question

Am running my application from a payara micro UberJar and would like to increase the memory allocated to the application. How can I do this at the point of creating the uberJar?

Answer 1

There are a couple of ways you can do this. The first way I'll mention is the preferred way:
1. Use asadmin commands
The latest edition of Payara Micro introduces an option called --postbootcommandfile which allows you to run asadmin commands against Payara Micro. Your file should include something like this:
delete-jvm-options -Xmx=512m
create-jvm-options -Xmx=1g
create-jvm-options -Xms=1g
You will need to make sure you delete the existing options before applying new ones.
You can then use the file similar to this:
java -jar payara-micro.jar --postbootcommandfile myCommands.txt --deploy myApp.war --outputuberjar myPayaraMicroApp.jar
Your settings should now persist in the resulting Uber JAR.
2. Supply a custom domain.xml
The alternative to this would be modifying a domain.xml of your own and overriding the in-built domain.xml with your own.
You can use the --rootdir option to get Payara Micro to output its configuration to a directory so you can make changes there. This process is outlined in this blog:
http://blog.payara.fish/working-with-external-configuration-files-in-payara-micro
If you already have a custom domain.xml to hand, you can use the --domainconfig property to supply it, as follows:
java -jar payara-micro.jar --domainconfig myCustomDomain.xml --deploy myApp.war --outputuberjar myPayaraMicroApp.jar
After following either of these methods, you can simply start the resulting JAR and all the settings and configuration will be applied:
java -jar myPayaraMicroApp.jar

Answer 2

Payara Micro uber JAR is a plain JAR and it doesn't start a new JVM like Payara Server does. Therefore there's no way to modify JVM memory settings from within the JAR as the JVM is already started. Although it's possible to add the JVM settings into the Payara Micro configuration, they are ignored and not applied. Those configuration values are only used within Payara Server.
With Payara Micro uber JAR, you need to specify the JVM options on the command line, like this:
java -Xmx=1g -Xms=1g -jar myPayaraMicroApp.jar
If you need to specify JVM arguments in the uber JAR, you need to use a solution like capsule.io to wrap the JAR into a launcher JAR that would spawn a separate JVM for Payara Micro and pass the arguments to it.