I have recently implemented distributed maps on my nodes using Hazelcast, where each physical server (Master node + slaves) represents a cluster. I am looking to further leverage the benefits of this cache by assigning tasks with significant data overlap to the same server. Simply stated, I would like tasks from "Job A" to only execute on a master node and its slaves (if any).

Unfortunately this does not appear to be easily implemented. The JobSLA class setMaxNodes() method is similar to what I would want, except it would not enforce any relationship between nodes selected. I've considered an approach using Execution Policies to favor certain servers by IP, but my cloud IP addresses are not known when my client submits the tasks.

I can see two possible improvements in JobSLA which would enable my desired capability:

• Add an argument to setMaxNodes(), or a new method, which applies the maximum only to Master Nodes; and permits assignment to the slave nodes of the assigned master. e.g., setMaxMasterNodes(2) would limit that job to processing on two master nodes and their corresponding slave(s), if any.
• Add a method setMaxProperties(int n,String key) which would evaluate the same properties used in Execution Policies and permit only a maximum of n unique values of the property identified by key. e.g., setMaxProperties(2,"ipv4.addresses") would allow that job to execute on no more than two unique servers (as determined by matching the IP addresses string).