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Heap Space

Node.js runtime heap space metrics, provided by spectator-js-nodejsmetrics.

Metrics

Data is gathered from the v8.getHeapSpaceStatistics method, for each space listed.

Space categories:

  • new_space: Where new allocations happen; it is fast to allocate and collect garbage here. Objects living in the New Space are called the Young Generation.
  • old_space: Object that survived the New Space collector are promoted here; they are called the Old Generation. Allocation in the Old Space is fast, but collection is expensive so it is less frequently performed.
  • code_space: Contains executable code and therefore is marked executable.
  • map_space: Contains map objects only.
  • large_object_space: Contains promoted large objects which exceed the size limits of other spaces. Each object gets its own mmap region of memory and these objects are never moved by GC.

Common Dimensions

The following dimensions are common to the metrics published by this module:

  • nodejs.version: The version of the Node.js runtime.

nodejs.spaceSize

The allocated size of the space.

Unit: bytes

Dimensions:

  • id: Space category.

nodejs.spaceUsedSize

The used size of the space.

Unit: bytes

Dimensions:

  • id: Space category.

nodejs.spaceAvailableSize

The available size of the space.

Unit: bytes

Dimensions:

  • id: Space category.

nodejs.physicalSpaceSize

The physical size of the space.

Unit: bytes

Dimensions:

  • id: Space category.