How many EAP instances can run on a server (per core / Memory)
Needs to be completely rewritten for EAP 6 https://access.redhat.com/kb/docs/DOC-53064 How many JBoss EAP instances can be installed on a server ? Article ID: 53064 - Created on: Dec 15, 2010 11:45 AM - Last Modified: Mar 29, 2011 11:26 AM Issue How many JBoss EAP instances JVMs can be installed on one RHEL linux OS? What is the maximum number for JBoss EAP nodes that can be installed on server i.e On Linux or Windows? My application has 48 cores and 256 GB of RAM with no virtualization. How many JBoss instances can be installed ? Does Red Hat have any recommendation on how many JBoss-JVM instances can be installed per machine. Not taking into account the custom application from the customer. I would like to have a response along the lines of "Only one JBoss instance per core is recommended" or "Only one JBoss instance per thread is recommended" or "The only limit for the number of JBoss instances is the RAM" or "The only limit for the number of JBoss instances are the ports available". Does Red Hat have a use case from a customer application that heavily utilises CPU resources? If so, how many JBoss instances were installed within that architecture? Environment JBoss Enterprise Application Platform (EAP) Resolution There are so many variables that it is impossible to be very specific. However, we can say at least something about the upper limit. You would not want to have more JVMs than there are CPUs/cores, and likely you would want to add some safety factor for kernel processing (e.g. leave 1 or more CPUs dedicated to the OS). And if you are using parallel garbage collectors, you would want to have at least 2 CPUs/cores per JVM. The other hard limit is physical memory. The sum of the heap, perm gen, thread stacks, and native JVM memory of all JVMs should not exceed available physical memory so as to avoid swapping. Beyond that it's not possible to make any predictions as there are so many variables involved. It would require testing and is best to have a Red Hat consulting engagement for this. A couple of things to note On a 64 bit OS, that is well tuned, there should be little reason to have multiple EAP instances other than redundancy. It is more common to have multiple EAP instances on a 32 bit OS due to the 4GB address space limitation where one wants to take advantage of the available RAM.