Undertow - HTTP Port opened before applications deployed

[abodycombe]

I have an issue deploying Wildfly 10.1.Final inside an Azure WebApp.

Within the Azure platform, a WebApp is considered "up" when the HTTP Port starts accepting requests, so Azure will direct requests to Wildflty as soon as Undertow starts listening for HTTP Requests.

However, Undertow starts listening on the socket while the Servlet container is still deploying the .war files, meaning Azure starts sending requests to Wildfly before the AppServer is ready, and clients see occasional 503 errors depending on which instance is hit.

This negatively affects the availability of the Wildfly server within Azure.

What I really need, is a way to delay the startup of Undertow until the Servlet container has completed the application deployment process.

Is that possible?

[pvs.1.jboss]

We run Apache fronting WildFly with AJP.  Apache will direct requests to WildFly as soon as Undertow Starts listening as well. We get 500 and 503 error responses depending on the time of startup processing. Even the HTTP listener will cause the same issues.

I was going to ask if you found a solution but I found the following and thought others may have the same problems and can save them some time:

Design notes for graceful startup

Coming in WildFly 11

WildFly 11 CR1 is now available! · WildFly

Unless there really is some work around for WildFly 10 this is a show stopper for the project I am on at least.

[abodycombe]

The graceful startup feature may indeed solve this problem - At some point, I intend to try this out, and I'll post the results of any investigation

[pferraro]

This issue was one of the primary motivations for the mod_cluster project.  The mod_cluster load balancer is application lifecycle aware such that availability of a web application is determined per deployment rather than based on a monolithic assumption about an open socket.  This prevents not just 500/503 errors during server startup/shutdown, but also 404 errors following undeploy of a single application.

Undertow can even be configured to behave as a mod_cluster reverse proxy (I realize the names are confusing, we're working on it...) using standalone-load-balancer.xml.

https://docs.jboss.org/author/display/WFLY10/Using+Wildfly+as+a+Load+Balancer