Apache Cluster + Tomcat websocket

Question

We've recently configured a new Cluster with the following configuration:

   www.mydomain.com
           |        
    APACHE + MOD_JK (AJP)
     Load Balancer
      /           \
  Tomcat1      Tomcat2

All the requests are made through HTTPS and the two tomcat instances are using SessionReplication via DeltaManager.

The cluster and all the wep-apps are working just fine.

Now one of these webapps requires the use of WebSockets with WSS:// protocol and i'm getting this exception

java.lang.UnsupportedOperationException: HTTP upgrade is not supported by this protocol

Has anyone ever a clue on what is causing this ?

score 3 · Answer 1 · edited May 14 '25 at 14:48

3

As discussed on the tomcat-users mailing list: "[...] the AJP protocol does not support upgrading to other protocols (e.g. websocket, HTTP/2)."

This means you'd have to use some other method of proxying these connections to your Tomcat instances. As Tux_DEV_NULL mentioned you could use mod_proxy_wstunnel for this.

edited May 14 '25 at 14:48

StackzOfZtuff

2,045

answered Oct 16 '17 at 08:32

vdstw

86

score 1 · Accepted Answer · edited May 14 '25 at 14:46

1

You need to install mod_proxy_wstunnel apache module.

edited May 14 '25 at 14:46

StackzOfZtuff

2,045

answered Oct 16 '17 at 08:21

Tux_DEV_NULL

1,123

Apache Cluster + Tomcat websocket

2 Answers2