Add job table to state API (#5076)

python/ray/state.py

@@ -385,6 +385,76 @@ class GlobalState(object):
 
         return _parse_client_table(self.redis_client)
 
+    def _job_table(self, job_id):
+        """Fetch and parse the job table information for a single job ID.
+
+        Args:
+            job_id: A job ID or hex string to get information about.
+
+        Returns:
+            A dictionary with information about the job ID in question.
+        """
+        # Allow the argument to be either a JobID or a hex string.
+        if not isinstance(job_id, ray.JobID):
+            assert isinstance(job_id, str)
+            job_id = ray.JobID(hex_to_binary(job_id))
+
+        # Return information about a single job ID.
+        message = self.redis_client.execute_command(
+            "RAY.TABLE_LOOKUP", gcs_utils.TablePrefix.Value("JOB"), "",
+            job_id.binary())
+
+        if message is None:
+            return {}
+
+        gcs_entry = gcs_utils.GcsEntry.FromString(message)
+
+        assert len(gcs_entry.entries) > 0
+
+        job_info = {}
+
+        for i in range(len(gcs_entry.entries)):
+            entry = gcs_utils.JobTableData.FromString(gcs_entry.entries[i])
+            assert entry.job_id == job_id.binary()
+            job_info["JobID"] = job_id.hex()
+            job_info["NodeManagerAddress"] = entry.node_manager_address
+            job_info["DriverPid"] = entry.driver_pid
+            if entry.is_dead:
+                job_info["StopTime"] = entry.timestamp
+            else:
+                job_info["StartTime"] = entry.timestamp
+
+        return job_info
+
+    def job_table(self):
+        """Fetch and parse the Redis job table.
+
+        Returns:
+            Information about the Ray jobs in the cluster,
+            namely a list of dicts with keys:
+            - "JobID" (identifier for the job),
+            - "NodeManagerAddress" (IP address of the driver for this job),
+            - "DriverPid" (process ID of the driver for this job),
+            - "StartTime" (UNIX timestamp of the start time of this job),
+            - "StopTime" (UNIX timestamp of the stop time of this job, if any)
+        """
+        self._check_connected()
+
+        job_keys = self.redis_client.keys(gcs_utils.TablePrefix_JOB_string +
+                                          "*")
+
+        job_ids_binary = {
+            key[len(gcs_utils.TablePrefix_JOB_string):]
+            for key in job_keys
+        }
+
+        results = []
+
+        for job_id_binary in job_ids_binary:
+            results.append(self._job_table(binary_to_hex(job_id_binary)))
+
+        return results
+
     def _profile_table(self, batch_id):
         """Get the profile events for a given batch of profile events.
 
@@ -982,6 +1052,20 @@ state = GlobalState()
 global_state = DeprecatedGlobalState()
 
 
+def jobs():
+    """Get a list of the jobs in the cluster.
+
+    Returns:
+        Information from the job table, namely a list of dicts with keys:
+        - "JobID" (identifier for the job),
+        - "NodeManagerAddress" (IP address of the driver for this job),
+        - "DriverPid" (process ID of the driver for this job),
+        - "StartTime" (UNIX timestamp of the start time of this job),
+        - "StopTime" (UNIX timestamp of the stop time of this job, if any)
+    """
+    return state.job_table()
+
+
 def nodes():
     """Get a list of the nodes in the cluster.