Heap

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

Metrics¶

Data is gathered from the v8.getHeapStatistics method.

Common Dimensions¶

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

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

nodejs.doesZapGarbage¶

Whether or not the --zap_code_space option is enabled.

This makes V8 overwrite heap garbage with a bit pattern. The RSS footprint (resident memory set) gets bigger because it continuously touches all heap pages and that makes them less likely to get swapped out by the operating system.

Unit: boolean

nodejs.heapSizeLimit¶

The absolute limit the heap cannot exceed (default limit or --max_old_space_size).

Unit: bytes

nodejs.mallocedMemory¶

Current amount of memory, obtained via malloc.

Unit: bytes

nodejs.peakMallocedMemory¶

Peak amount of memory, obtained via malloc.

Unit: bytes

nodejs.totalAvailableSize¶

Available heap size.

Unit: bytes

nodejs.totalHeapSize¶

Memory V8 has allocated for the heap. This can grow if usedHeap needs more.

Unit: bytes

nodejs.totalHeapSizeExecutable¶

Memory for compiled bytecode and JITed code.

Unit: bytes

nodejs.totalPhysicalSize¶

Committed size.

Unit: bytes

nodejs.usedHeapSize¶

Memory used by application data.

Unit: bytes