User Define Scheduler

From JStorm 0.9.0,JStorm provides a very powerful scheduling features, meet most needs Basically. Before learning how to use the new scheduling,Please to learn what features provided by the introduction of JStorm 0.9.0

Interface

Set the default memory size for each worker

     ConfigExtension.setMemSizePerWorker(Map conf, long memSize)

modify the configurations, for example:

worker.memory.size: 2147483648

Set weights for each worker's cgroup, cpu

     ConfigExtension.setCpuSlotNumPerWorker(Map conf, int slotNum)

modify the configurations, for example:

worker.cpu.slot.num: 3

Set whether to use the old distribution

     ConfigExtension.setUseOldAssignment(Map conf, boolean useOld)

modify the configurations, for example:

use.old.assignment: true

Set to force one component of the task to work on different nodes

     ConfigExtension.setTaskOnDifferentNode(Map conf, boolean isIsolate)

modify the configurations, for example:

task.on.differ.node: true

Set to force topology running on special nodes

     conf.put(Config.ISOLATION_SCHEDULER_MACHINES, List<String> isolationHosts);

modify the configurations, for example:

isolation.scheduler.machines: 
    - machine1.com
    - machine2.com
    - machine3.com

Custom worker assigned

     WorkerAssignment worker = new WorkerAssignment();
     worker.addComponent(String compenentName, Integer num);      //Add a task on this worker
     worker.setHostName(String hostName);      //force this worker on one machine 
     worker.setJvm(String jvm);                //this can be skipped, set jvm parameters of this worker 
     worker.setMem(long mem);                  //this can be skipped, set the worker's memory size
     worker.setCpu(int slotNum);               //this can be skipped, set the cpu's weights
     ConfigExtension.setUserDefineAssignment(Map conf, List<WorkerAssignment> userDefines)

PS:Each worker's argument does not need to be all set, Under the premise that worker attributes in the legal premise, even if only to set up some parameters will still take effect.

modify the configurations, for example:

use.userdefine.assignment: 
    - {"port":null,"nodeId":null,"componentToNum":"{\"componentname\":2}","mem":2147483648,"cpu":null,"hostName":"host1.com","jvm":null}
    - {"port":null,"nodeId":null,"componentToNum":"{\"componetname2\":2}","mem":null,"cpu":null,"hostName":null,"jvm":null}

Default Scheduling Algorithm

•      Worker will be equally assign to every supervisors.
  

•      Task will be equally assign to every worker exception user defined workers.
  

•      Avoid assign the same kind of tasks on one worker as much as possible. Try best to assign sender/recever peer task in one worker.
  

•      New topology won't effect the old topology's assignment
  

•      User defined assignment has the highest priority, then the Old assignment if enable, at last the default assignment.