IssueTracker

I opened another issue, but it was incorrectly closed. It's a bug, and the link that they shared with me doesn't correspond to the problem.

I have a Spring Boot application and I migrated my project from Java 8 to Java 17, and I could deploy normally on october 14. I could see in the logs that the app was running on Java 17.

On october 15, I just added a small feature, with no changes in the configuration, and then I started to get the error:

(gcloud.app.deploy) Error Response: [9] An internal error occurred while processing task /app-engine-flex/flex_await_healthy/flex_await_healthy>2023-10-18T13:49:28.335Z4576.uc.1: Start command: java -showversion -Xms3276M -Xmx3276M -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:+PrintCommandLineFlags -jar app.jar
-XX:InitialHeapSize=3435134976 -XX:MaxHeapSize=3435134976 -XX:+ParallelRefProcEnabled -XX:+PrintCommandLineFlags -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseG1GC 
openjdk version "1.8.0_345"
OpenJDK Runtime Environment (Temurin)(build 1.8.0_345-b01)
OpenJDK 64-Bit Server VM (Temurin)(build 25.345-b01, mixed mode)

Exception in thread "main" java.lang.UnsupportedClassVersionError: com/project/football/ApiApplication has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 52.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:473)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
	at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:151)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:348)
	at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:46)
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
	at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)

I made no changes in configuration, but since october 15 I got this error every single day and I can't deploy my application.

It's not an error in my application, since I already deployed with success and it doesn't work anymore. It's a bug! My configuration file says to app engine that I want a Java 17 Runtime, but app engine tries to run my app in a JDK 8 Runtime. I tried many times!

I wrote my app.yaml following the Google Cloud instructions for app engine flex running with Java 17:

runtime: java
env: flex
runtime_config:
  operating_system: ubuntu22
  runtime_version: 17
  
service: api
  
handlers:
- url: /.*
  script: this field is required, but ignored
  
resources:
  cpu: 1
  memory_gb: 4
  disk_size_gb: 40


automatic_scaling:
  min_num_instances: 1
  max_num_instances: 1
  
  cpu_utilization:
    target_utilization: 0.85
  
env_variables:                      
    SPRING_PROFILES_ACTIVE: prod