Heap dump

slicer provides a simplistic overview of a JVM’s heap structure described by a HPROF file.

Caution

HPROF files can be very large in size, and despite slicer’s efforts, analysis of them can be very memory-, I/O- and CPU-intensive.

As of now, it is also advised to use a V8-based browser (i.e. Chromium) rather than ones based on SpiderMonkey or JavaScriptCore (i.e. Firefox or Safari) when analyzing heap dumps - this is purely for performance reasons; the analysis will work the same, however it may be significantly slower.

slicer does not perform extensive analysis, e.g. memory leak detection, which tools such as Eclipse MAT and VisualVM do, it instead creates heap summaries.

A heap summary is a listing of all types on the heap, such as class instances, object arrays and primitive arrays.

Note

Class instance sizes are merely educated estimates - it is impossible to concretely define them without having access to the actual heap of the JVM, read more here.