Call to metrics service fails sometimes

[laurenwalker]

Sometimes the call to the metrics service on the MetadataView fails due to a time out error.

Example dataset where this happened at least twice: https://knb.ecoinformatics.org/view/urn:uuid:0beca8b9-7fcb-468f-9118-2bcc9f641f90

There are two issues here:

1. Why is the request failing
2. When it fails, the metric count pill on the buttons keep spinning. When a call to the metric service fails, we should remove the spinner from the button and replace with some kind of error icon. (Maybe a question mark) and the tooltip should say that the count could not be retrieved at this time.

[rushirajnenuji]

Hey @laurenwalker - thanks for writing up this issue.

So, regarding 1 - Dave, Chris and I looked into the error and turns out there was some issue with the Multi-processing implementation of the same. We eventually ended up deciding to keep the processing serial for now, till we come up with a better solution.

With serial processing on the back-end, the XHR request might take a while to load the metrics. So, in this commit, I've extended the XHR request timeout to the metrics service to 50s.

Regarding 2 - yes, the icon-spinner keeps on spinning when the call fails which is wrong. So, I made a few changes in the above commit. Here's what the UI looks like -

I have a small doubt regarding the implementation:

In the MetricView, I have -

            ...

            // waiting for the fetch() call to succeed.
            this.listenTo(this.model, "sync", this.renderResults);

            // in case when there is an error for the fetch call.
            this.listenTo(this.model, "error", this.renderError);

Do we have to make sure that the MetricView stops listening for sync event of the MetricsModel in case of the error event?

[laurenwalker]

Thanks Rushi! Some thoughts:

• I would suggest changing the tooltip text to: The number of citations/downloads/views could not be retrieved right now. We haven't been using the word metric in the UI since it's a bit jargony.

• I think we should also gray out the buttons when the request fails, the same way we do when the count is 0.

• After looking at the question mark, I think I like the exclamation sign icon better: https://fontawesome.com/v3.2.1/icon/exclamation-sign

• No, we do not have to stop listening to the sync event. It doesn't really hurt anything to keep that listener there.

[rushirajnenuji]

Hey Lauren - I appreciate you taking time and penning down these suggestions.

• Yes, I agree to the first point. It would be good to remove metric jargon from the tool-tip.

• We don't really gray out the metric buttons right now. I remember Matt suggested - that we require the buttons to be enabled because we have the functionality to navigate modals. But, now that I think of it, we should just keep the buttons enabled if either one of the three is non-zero. So, we would gray-out (and disable button) in two scenarios: if all the three metrics are zeros; and if the metrics request call fails. Please let me know if this sounds reasonable.

• Okay, I'll place in the exclamation sign when the call fails.

• And, it is good not to explicitly have to stop listening. Makes things easier!

I'll go ahead and start working on these changes. Thanks again!

[rushirajnenuji]

Reference commit: https://github.com/NCEAS/metacatui/commit/684c273a7ef7543cfe01e40b25c2f53a81a8dc11

Disabled the icons on metrics-service failure: