Reducing the number of Hazelcast streams

For testing purposes, I want to run multiple instances of Hazelcast on one node. Hazelcast assumes that it is running a whole node and therefore it creates a large enough number of threads to load all cores completely (in fact, more). On my 8-core Linux node Hazelcast creates 74 threads per instance, which quickly breaks the user thread limit. (Yes, I know this can be changed with ulimit

.)

From jconsole viewing themes:

• hz.hzInstance_1_dev.scheduled
• hz.hzInstance_1_dev.generic-operation.thread (x16)
• hz.hzInstance_1_dev.partition-operation.thread (x16)
• hz.hzInstance_1_dev.response
• hz.hzInstance_1_dev.event (x5)
• hz.hzInstance_1_dev.wait-notify
• hz.hzInstance_1_dev.wan (x16)
• hz.hzInstance_1_dev.cached.thread
• hz.hzInstance_1_dev.migration
• hz.hzInstance_1_dev.IO-thread-in (x3)
• hz.hzInstance_1_dev.IO-thread-out (x3)
• hz.hzInstance_1_dev.IO-thread-acceptor
• hz.hzInstance_1_dev.cached-thread (x8)
• hz.hzInstance_1_dev.HealthMonitor

Some of the flow counts can be reduced by setting the Hazelcast System Properties :

• generic-operation.thread = hazelcast.operation.generic.thread.count
  
  
• partition-operation.thread = hazelcast.operation.thread.count
  
  
• IO-thread = hazelcast.io.thread.count
  
  
• event = hazelcast.event.thread.count
  
  

By default, the wan, generic-operation and partition-operation thread numbers are 2 x CPU core count. There seems to be no way to reduce the number of wan threads.

Is there a way to specify how many cores Hazelcast should use, rather than separately specifying generic-operation.thread

and partition-operation.thread

? The processor proximity setting does not work as Hazelcast still thinks it has access to all cores.

Is there a way to change the number of WAN replication threads?