Failed startup of context AppengineWebAppContext

JayaPriya · 02-28-2025 12:03 AM

Dear,

Recently for some of the app engine (using java 17 & appengine-maven-plugin version 2-2-0), When user opens the app link it is displaying "javax.servlet.UnavailableException: Class loading error for holder _ah_default==com.google.apphosting.runtime.jetty9.ResourceFileServlet@{jsp=null,order=-1,inst=false,async=false,src=DESCRIPTOR:file:///workspace/WEB-INF/quickstart-web.xml,STARTING}" error for sometime & issue solving automatically.

Without any deployment the issue is occurring & automatically working after sometimes.

Can somebody help on it how to handle this issue & root cause in app engine?

ChieKo

Hi @JayaPriya ,

Welcome to the Google Cloud community!

The problem you're encountering on Google App Engine (GAE) typically arises from class loading issues, especially when deploying Java applications that utilize JSPs or servlets. GAE's standard environment supports specific Java versions. If you're using Java 17, be aware that the standard environment may not support it. Consider using the flexible environment or downgrading to a supported version like Java 8. Conflicting or missing dependencies can cause class loading issues. Review your pom.xml to ensure that all necessary dependencies are included and that there are no conflicting versions.

Was this helpful? If so, please accept this answer as “Solution”. If you need additional assistance, reply here within 2 business days and I’ll be happy to help.

JayaPriya

Hi @ChieKo ,

Thank you for the support & response.

As App Engine standard environment no more support Java 8 runtime, we had migrated our project to Java 17 with legacy bundle enabled. As per the deployment descriptor , we had the web.xml & application was running for more than a year. But recently on February 2025 we are receiving the failed to startup error occasionally while a new instance is created when end user access the application. Do we have an insight if any update has been done in app engine related to jetty or appengine-maven-plugin.