I managed to calculate the Disk throughput, but I still have the problem of getting stale data. I noticed that the values of the disk metrics change once per minutes, while the values for cpu, memory and network are constantly updated. Is there a way to overcome this problem? Thanks.
Best Regards, Max From: Aravindan Vijayan <[email protected]> To: "[email protected]" <[email protected]> Date: 08/02/2017 19:12 Subject: Re: how to interpret the host metrics retrieved from Rest API Hi Massimilian, Ambari Metrics Service uses psutil library to collect system metrics. The metrics's explanation can be found here - https://pythonhosted.org/psutil/ . In case there is no metric in psutil with a given name in AMS, it might have been re-named. Please refer to the following file for renaming - https://github.com/apache/ambari/blob/trunk/ambari-metrics/ambari-metrics-host-monitoring/src/main/python/core/host_info.py . -- Thanks and Regards, Aravindan Vijayan From: Massimilian Mattetti Reply-To: "[email protected]" Date: Wednesday, February 8, 2017 at 12:41 AM To: "[email protected]" Subject: how to interpret the host metrics retrieved from Rest API Hi all, I am trying to monitor the resource usage of a cluster by pulling the metrics from the rest API of Ambari (Version 2.4.2.0). I am sending request with the following path: http://ambari-server:8080/api/v1/clusters/test/hosts?fields=Hosts/last_heartbeat_time,metrics There are few metrics that are really hard to understand. For instance, the metrics of the disk: "disk" : { "disk_free" : 3278.83, "disk_total" : 4948.57, "read_bytes" : 5.0036226048E10, "read_count" : 197716.0, "read_time" : 8.7998397E7, "write_bytes" : 1.0003064832E10, "write_count" : 822311.0, "write_time" : 1.6088341E7 }, How should I interpret the read_time? Why the values take minutes to change (I am pulling every 10 seconds) even if the host is under high disk I/O? Is there a legend that explains the meaning of each one of the metrics? Thanks. Best Regards, Max
