jemalloc metrics

[Velfi]

This PR adds the following new metrics when running Linux with the global-allocator feature:

• apollo_router_jemalloc_active: Total number of bytes in active pages allocated by the application.
• apollo_router_jemalloc_allocated: Total number of bytes allocated by the application.
• apollo_router_jemalloc_mapped: Total number of bytes in active extents mapped by the allocator.
• apollo_router_jemalloc_metadata: Total number of bytes dedicated to metadata, which comprise base allocations used for bootstrap-sensitive allocator metadata structures and internal allocations.
• apollo_router_jemalloc_resident: Maximum number of bytes in physically resident data pages mapped by the allocator, comprising all pages dedicated to allocator metadata, pages backing active allocations, and unused dirty pages.
• apollo_router_jemalloc_retained: Total number of bytes in virtual memory mappings that were retained rather than being returned to the operating system via e.g. munmap(2) or similar.

---

Checklist

Complete the checklist (and note appropriate exceptions) before the PR is marked ready-for-review.

• PR description explains the motivation for the change and relevant context for reviewing
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• Changeset is included for user-facing changes
• Changes are compatible¹
• Documentation² completed
• Performance impact assessed and acceptable
• Metrics and logs are added³ and documented
• Tests added and passing⁴
  • Unit tests
  • Integration tests
  • Manual tests, as necessary

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Notes

Footnotes

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[apollo-librarian]

✅ Docs preview ready

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File Changes

0 new, 7 changed, 1 removed

* graphos/routing/(latest)/security/jwt.mdx
* graphos/routing/(latest)/self-hosted/containerization/docker.mdx
* graphos/routing/(latest)/self-hosted/containerization/index.mdx
* graphos/routing/(latest)/self-hosted/containerization/kubernetes/other-considerations.mdx
* graphos/routing/(latest)/self-hosted/index.mdx
* graphos/routing/(latest)/_sidebar.yaml
* graphos/routing/v1/operations/subscriptions/index.mdx
- graphos/routing/(latest)/self-hosted/containerization/docker-router-only.mdx

Build ID: aa3f98dd98ae5cd6872aa81c

URL: https://www.apollographql.com/docs/deploy-preview/aa3f98dd98ae5cd6872aa81c

[garypen]

Looks great. I've made a suggestion about trying to leverage the jemalloc stats cache.

[garypen]

One small fix so it can compile.

I made the fix on my laptop and then tested in a linux VM (that was a whole thing...) and found the integration test failed. Extract from fail:

thread 'integration::metrics::test_jemalloc_metrics_are_emitted' panicked at apollo-router/tests/integration/../common.rs:988:9:
'apollo_router_jemalloc_active' not detected in metrics
# HELP apollo_router_cache_miss_time Time to check the cache for an uncached value in seconds

So, it looks like there's an issue with the creation of the metric.

[BrynCooke]

@mergify.io backport 1.x