FAQ

Noteworthy articles from mod_cluster user forum

Q: I started mod_cluster and it looks like it's using only one of the workers

A: One must give the system some time, in matter of the amount of new sessions created, to settle and pick other nodes. An example from an actual environment: You have 3 nodes with the following Load values:

Node jboss-6,   Load: 20
Node jboss-6-2, Load: 90
Node jboss-6-3, Load:  1

Yes, this means that jboss-6-2 is almost not loaded at all whereas jboss-6-3 is desperately overloaded. Now, I send 1001 requests, each representing a new session (the client is forgetting cookies). The distribution of the requests will be as follows:

Node jboss-6   served 181 requests
Node jboss-6-2 served 811 requests
Node jboss-6-3 served   9 requests

So, generally, yes, the least loaded box received by far the greatest amount of requests, but it did not receive them all. Furthermore, and this concerns your case, for some time from the start, it was jboss-6 who was getting requests.

This whole magic is in place in order to prevent congestion.

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