Disable downtime logs in WebSphere and how to replace JDK

[Solution and steps]
Solution 1: Disable JIT
Go to the WebSphere console and choose "Application Server"> "server1"> "Process Definition"
Go to "Java Virtual Machine", select "Disable JIT", and restart websphere.
This solution is simple, but the system performance is poor. Because the class bytecode is directly run, the running efficiency is poor.

Solution 2: upgrade to the latest JVM
First download the latest JDK environment and install
Start websphere, modify the "java_home" value in the "environment variable", and use the latest downloaded JDK
Then copy the WebSphere/appserver ($ was_home)/Java/lib/ibmtools. jar file to the lib directory under the latest JDK java_home directory.
Copy the files in the WebSphere/appserver ($ was_home)/Java/JRE/lib/EXT directory that do not exist in the latest JDK java_home/JRE/lib/Ext!
Then restart websphere.