Increase TaskID size by 2 bytes, taken from JobID (#6425)

* Increase TaskID size by 2 bytes, taken from JobID

* comments

* check max job id

* fix doc

* fix local mode

python/ray/includes/unique_ids.pxi

@@ -288,6 +288,7 @@ cdef class JobID(BaseID):
 
     @classmethod
     def from_int(cls, value):
+        assert value < 65536, "Maximum JobID integer is 65535."
         return cls(CJobID.FromInt(value).Binary())
 
     @classmethod

python/ray/worker.py

@@ -1111,9 +1111,8 @@ def connect(node,
         if setproctitle:
             setproctitle.setproctitle("ray::IDLE")
     elif mode is LOCAL_MODE:
-        # Code path of local mode
         if job_id is None:
-            job_id = JobID.from_int(random.randint(1, 100000))
+            job_id = JobID.from_int(random.randint(1, 65535))
         worker.worker_id = ray.utils.compute_driver_id_from_job(
             job_id).binary()
     else: