What is the difference on ONTAP for the URLs"/cluster/metrics" and "/cluster"

[Ruoyi]

When I query ONTAP cluster to get the performance metrics; dedicated URL /cluster/metrics doesn't work instead under the /cluster when explicit input of field parameter is provided it returns the data for the performance counters.

Formed URLs in both the scenarios looks as listed below :

1. https://ONTAP_CLUSTER_IP/api/cluster/metrics?interval=1h&return_timeout=15&return_records=true

     Returns 0 records

2. https://ONTAP_CLUSTER_IP/api/cluster?return_records=true&return_timeout=15&fields=metric

     Returns valid records

Is this expected behavior? 
If yes then what is the use of /cluster/metrics ?

[Navaneethakrishnan]

I am facing the same issue. Do we have any solution for this?

[elementx]

Works fine for me.

Various records from the past hour (the most recent hour, sampled over 15 seconds - I got 239 of them back, which equals 59.75 minutes).

Individual record:

> Is this expected behavior?

The above is exactly what I expected to see.

> If yes then what is the use of /cluster/metrics ?

To help us retrieve historical performance metrics for the cluster. That's what the documentation says and that's what it does.

/cluster is not even related to metrics, although it happens to contain a set of the current performance metrics (which /cluster/metrics does not do) and some other information unrelated to performance metrics.

[Navaneethakrishnan]

Hi @elementx . Thanks for the detailed explanation. 

But I didn't any records from /cluster/metrics API. I can get the current metrics from /cluster API.

do I need to enable anything in cluster level to get the historical data? 
Note:
Cluster version: 9.9.1

[elementx]

The first difference may be I went to: https://${CLUSTER_IP}/api/cluster/metrics?interval=1h which is slightly shorter than the URL from the original post. I haven't tried the OP's full example. 

The second may be that my ONAP is 9.12.1 which is reasonable considering it's been around for a while and the OP doesn't specify any particular version.

ONTAP 9.9.1 has the same method so I think my URL should work the same but if it doesn't then it may be ONTAP 9.9.1-specific. In that case I would check the KB or ask Support.

Maybe someone with 9.9.1 can verify what they see on their end.

[elementx · Accepted solution]

I also tried the OPs full link to /cluster/metrics, it also works on my ONTAP 9.12.1 as shown here.

I should add s51 is node management IP.

I also tried the link against cluster management IP - that also worked.

Proper (unfiltered) output for /cluster, on the other hand, reveals it's not about performance, although it does contain the latest sample.

So I think the OP's questions are answered:

- /cluster/metrics provides historic high-level metrics

- /cluster provides cluster state with various cluster information (not related to performance) including just the latest sampling of high-level metrics

- additional metrics are available via other API methods

If it doesn't work on an older version after the metrics were introduced but before 9.12.1, I suggest checking the KB or contacting Support.