Add a web dashboard for monitoring node resource usage (#4066)

python/ray/ray_constants.py

@@ -54,6 +54,8 @@ INFEASIBLE_TASK_ERROR = "infeasible_task"
 REMOVED_NODE_ERROR = "node_removed"
 MONITOR_DIED_ERROR = "monitor_died"
 LOG_MONITOR_DIED_ERROR = "log_monitor_died"
+REPORTER_DIED_ERROR = "reporter_died"
+DASHBOARD_DIED_ERROR = "dashboard_died"
 
 # Abort autoscaling if more than this number of errors are encountered. This
 # is a safety feature to prevent e.g. runaway node launches.
@@ -76,6 +78,9 @@ AUTOSCALER_UPDATE_INTERVAL_S = env_integer("AUTOSCALER_UPDATE_INTERVAL_S", 5)
 AUTOSCALER_HEARTBEAT_TIMEOUT_S = env_integer("AUTOSCALER_HEARTBEAT_TIMEOUT_S",
                                              30)
 
+# The reporter will report its' statistics this often (milliseconds).
+REPORTER_UPDATE_INTERVAL_MS = env_integer("REPORTER_UPDATE_INTERVAL_MS", 500)
+
 # Max number of retries to AWS (default is 5, time increases exponentially)
 BOTO_MAX_RETRIES = env_integer("BOTO_MAX_RETRIES", 12)
 
@@ -96,6 +101,8 @@ INFINITE_RECONSTRUCTION = 2**30
 PROCESS_TYPE_MONITOR = "monitor"
 PROCESS_TYPE_RAYLET_MONITOR = "raylet_monitor"
 PROCESS_TYPE_LOG_MONITOR = "log_monitor"
+PROCESS_TYPE_REPORTER = "reporter"
+PROCESS_TYPE_DASHBOARD = "dashboard"
 PROCESS_TYPE_WORKER = "worker"
 PROCESS_TYPE_RAYLET = "raylet"
 PROCESS_TYPE_PLASMA_STORE = "plasma_store"