Distributed semaphore on multiply services by curator

Question

I'm new to zookeeper and curator.

I want to use zookeeper and curator to control our services. The situation is that our services are based on hardware devices, so each device as a provider could only run one task at one time. As we have many devices, I design to use curator's semaphore to count the whole number, but how to find the exactly devices is a problem. Because one job might need many devices at one time to run (devices are independent), and the number can not be defined, so each time we need to lock N devices and to send the task info

e.g.As I thought, we register device as EPHEMERAL_SEQUENTIAL in curator:

/root/services/
              /devices00000001
              /devices00000002
              ...

whether we use a lock on each device or use a flag in znode's data, it will cost us a lot of time to find the available devices. So I wander if there are some common solutions to these problems? Maybe I should not use zookeeper but other software?

Answer 1

Use an InterProcessMutex for each device - I assume each device has some unique ID. Something like:

String path = ZKPaths.makePath("/some/base/path", deviceId);
InterProcessMutex lock = new InterProcessMutex(curator, path);
if ( lock.acquire(max, unit) ) {
    try {
        DO WORK HERE
    } finally {
        lock.release();
    }
}