CODEWITHSUNDEEP
javaout-of-memoryheap-memoryjvisualvmjhat
VenKatari
VenKatari

Reputation: 38

Java heapdump analysis find source for the instantiated objects

I am analyzing a heap dump using a jvisualvm. From the report I can see the classes, number of instances and the size occipied.

What I wanted to know is - the source (which class instantiated) of these objects. For a given object, if I could know all the source classes and the number of instances created by each of those classes, I guess it would be easy to identify the bad candidate.

Is this possible at all? If so, is there any tool better than the other to provide such information?

Upvotes: 2

Views: 1540

Answers (3)

user256717
user256717

Reputation:

Did you try 

jhat <yourdump>

assuming your creations are of the form:

private Blah blah = new Blah();

For every instance you can see who holds the reference to it. It also provides a powerful query language [OQL]. See for an example: jhat OQL AND in where clause

But if you created it somewhere else and simply passed it on to be held by another class field you won't be able to find it from memory dump [with any tool], as it is only a snapshot.

Upvotes: 0

Arndt
Arndt

Reputation: 1

Try:

http://dr-brenschede.de/bheapsampler for an easy to understand summary or http://www.eclipse.org/mat for a more detailed analysis

these tools do exaclty what you're looking for

Upvotes: 0

Peter Lawrey
Peter Lawrey

Reputation: 533530

YourKit provides allocation tracing by size and by number. You can search for particular classes created and find hot spots. The evaluation version is free. ;)

Upvotes: 3

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