[APM] Fix stale custom links list after creating new link

[ogupte]

Closes #86989. Disable caching for fetched custom links

[elasticmachine]

Pinging @elastic/apm-ui (Team:apm)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 9ab18d9

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
apm	5.4MB	5.4MB	+1.0B

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@elasticmachine merge upstream

[cauemarcondes]

LGTM

[sorenlouv]

@cauemarcondes Didn't you recently add this? I suppose we added it for a reason - maybe we were seeing duplicate requests?

I'm wondering if we can keep the caching and solve it by improved cache invalidation. Afair calling refetch should override the existing cache - if not that's probably a bug.

[cauemarcondes]

@cauemarcondes Didn't you recently add this?

@sqren No, actually you added it when you refactored the custom link components. But I don't think removing it would be a problem, we already lazy-loading the API call (it's only called when the Action menu is opened). WDYT?

[sorenlouv]

Great, alzheimer's coming early 😴
Okay, removing it sgtm 👍

[ogupte]

refetch is working as expected, the issue here is with the callApmApi result being cached. It is invoked each time refetch is called, but with isCachable: true it returns immediately. There are 2 levels of caching here, calling refetch invalidates the first level, and setting isCachable: false disables the 2nd level.

[sorenlouv]

Outside the scope of this PR but shouldn't refetch always circumvent the cache?

[sorenlouv]

... thinking about this some more, it might be hard to handle automatically. We could pass a boolean to the handler that indicated whether the data we refetched:

  const { data = DEFAULT_DATA, status } = useFetcher(
    (callApmApi, refetched) =>
      callApmApi({ 
        isCachable: !refetched,
        endpoint: `GET /api/apm/foo`
      }),
    []
  );

But not sure how i feel about that...

[sorenlouv]

lgtm but please double check that refetch works as it should