Implicit Process creation when pushing a Spring boot application

Question

I am pushing a minimalistic Spring Boot web application on Cloud Foundry. My manifest looks like

---
applications:
- name: training-app
  path: target/spring-boot-initial-0.0.1-SNAPSHOT.jar
  instances: 1
  memory: 1G
  buildpacks:
    - java_buildpack     
  env:
    TRAINING_KEY_3: from manifest

When I push the application with Java Buildpack (https://github.com/cloudfoundry/java-buildpack/releases/tag/v4.45) , I see that it is creating an additional process of type -task which does not have any running instance though.

name:                training-app
requested state:     started
isolation segment:   trial
routes:              ***************************
last uploaded:       Thu 20 Jan 21:29:31 IST 2022
stack:               cflinuxfs3
buildpacks:          
isolation segment:   trial
    name             version                                                                     detect output   buildpack name
    java_buildpack   v4.45-offline-https://github.com/cloudfoundry/java-buildpack.git#f1b695a0   java            java

type:            web
sidecars:        
instances:       1/1
memory usage:    1024M
start command:   JAVA_OPTS="-agentpath:$PWD/.java-buildpack/open_jdk_jre/bin/jvmkill-1.16.0_RELEASE=printHeapHistogram=1 -Djava.io.tmpdir=$TMPDIR -XX:ActiveProcessorCount=$(nproc)
                 -Djava.ext.dirs=$PWD/.java-buildpack/container_security_provider:$PWD/.java-buildpack/open_jdk_jre/lib/ext -Djava.security.properties=$PWD/.java-buildpack/java_security/java.security $JAVA_OPTS" &&
                 CALCULATED_MEMORY=$($PWD/.java-buildpack/open_jdk_jre/bin/java-buildpack-memory-calculator-3.13.0_RELEASE -totMemory=$MEMORY_LIMIT -loadedClasses=13109 -poolType=metaspace -stackThreads=250 -vmOptions="$JAVA_OPTS") && echo JVM Memory Configuration:
                 $CALCULATED_MEMORY && JAVA_OPTS="$JAVA_OPTS $CALCULATED_MEMORY" && MALLOC_ARENA_MAX=2 SERVER_PORT=$PORT eval exec $PWD/.java-buildpack/open_jdk_jre/bin/java $JAVA_OPTS -cp $PWD/. org.springframework.boot.loader.JarLauncher
     state     since                  cpu    memory        disk         details
#0   running   2022-01-20T15:59:55Z   0.0%   62.2M of 1G   130M of 1G   

type:            task
sidecars:        
instances:       0/0
memory usage:    1024M
start command:   JAVA_OPTS="-agentpath:$PWD/.java-buildpack/open_jdk_jre/bin/jvmkill-1.16.0_RELEASE=printHeapHistogram=1 -Djava.io.tmpdir=$TMPDIR -XX:ActiveProcessorCount=$(nproc)
                 -Djava.ext.dirs=$PWD/.java-buildpack/container_security_provider:$PWD/.java-buildpack/open_jdk_jre/lib/ext -Djava.security.properties=$PWD/.java-buildpack/java_security/java.security $JAVA_OPTS" &&
                 CALCULATED_MEMORY=$($PWD/.java-buildpack/open_jdk_jre/bin/java-buildpack-memory-calculator-3.13.0_RELEASE -totMemory=$MEMORY_LIMIT -loadedClasses=13109 -poolType=metaspace -stackThreads=250 -vmOptions="$JAVA_OPTS") && echo JVM Memory Configuration:
                 $CALCULATED_MEMORY && JAVA_OPTS="$JAVA_OPTS $CALCULATED_MEMORY" && MALLOC_ARENA_MAX=2 SERVER_PORT=$PORT eval exec $PWD/.java-buildpack/open_jdk_jre/bin/java $JAVA_OPTS -cp $PWD/. org.springframework.boot.loader.JarLauncher
There are no running instances of this process.

I understand that it is a Springboot Web application , and that corresponds to the process of type web , however I do not know

Who is creating the process of type task
What is the purpose of this process ?

It would be great of someone is able to help me here.

Regards AM

score 0 · Accepted Answer · answered Jan 20 '22 at 20:34

Who is creating the process of type task

The buildpack creates both. This is what's been happening for a while, but recent cf cli changes are making this more visible.

What is the purpose of this process ?

I didn't add that into the buildpack so I can't 100% say its purpose, but I believe it is meant to be used in conjunction with running Java apps ask tasks on CF.

See this commit.

When you run a task, there is a --process flag to the cf run-task command which can be used to set a process to use as the command template. I believe the idea is that you'd set it to task so it can use that command to run your ask. See here for reference to that flag.

Implicit Process creation when pushing a Spring boot application

1 Answers1