dotMemory 2017.2 Help

Group by Generations

The Group by Generations view shows how objects from the selected set are distributed among generations. Use this view to determine whether you have too much large objects (which are collected less efficiently and produce heap fragmentation) or objects that live too long (e.g. potential memory leak).

The list of heaps consists of the following columns:

NameDescription
Generation A certain heap where objects from the set can be allocated: Generation 0, 1, 2, or Large object heap.
Total, bytes The size of a certain heap defined by GC.
Utilization A ratio that shows what part of a heap is occupied by objects from the set.
Objects count The number of objects from the set allocated in a certain heap.
Used, bytes Size of objects from the set allocated in a certain heap.

Example

/help/img/dotnet/2017.2/generations_2.png

Selecting Objects for Further Analysis

In the Group by Generations view, you can select the following subjects for further analysis:

To select objects of a particular generation:

  • Do one of the following:
    • Double-click the corresponding generation.
    • Right-click the generation and choose Open this object set.

    After this, the [Generation_name] subject will be added to the Analysis Path and the list of desired objects will be displayed in the Group by Types view.

To select the objects that are exclusively retained by the analyzed objects set:

  • Click the /help/img/dotnet/2017.2/open_retained_objects_button.png Open objects retained by this set button.

    After this, the Exclusively retained objects subject will be added to the Analysis Path and the list of desired objects will be displayed in the Group by Types view.

The Group by Generations view for the 'All Objects' set

If you analyze the All objects object set, the Group by Generations view provides additional information about the fragmentation of all heaps allocated for your app.

Use this view to determine whether you have too much large objects (which are collected less efficiently and produce heap fragmentation) or objects that live too long (e.g. potential memory leak). The main point of your interest here should be Large Object Heap as the only part of the managed heap which is not compacted (see .NET Memory Management Concepts).

The list of heaps consists of the following columns:

NameDescription
Map A certain heap where objects from the set can be allocated: Generation 0, 1, 2, or Large object heap.
Total, bytes The size of a certain heap defined by GC.
Utilization A ratio that shows what part of a heap is occupied by objects from the set.
Objects count The number of objects from the set allocated in a certain heap.
Fragmentation A level of fragmentation. The 0% fragmentation means that all free memory is located in a single block. Learn about how the fragmentation is calculated here.
Last modified: 29 August 2017

See Also