dotMemory 2020.3 Help

Control Profiling Session

After you run the profiling session, dotMemory will open the new Analysis tab and launch the profiled application.

Controlling profiling process 1

To control the profiling process, use the following buttons on the top of the page Pos 2:

  • Force GC: forces full garbage collection in the application.

  • Kill Process: kills the currently selected process of the application.

  • Kill All Processes*: kills all processes of the application.

  • Detach**: detaches the profiler from the application but keeps the application running.

  • Collect Allocations: enables and disables collecting memory allocation data.
    Use this option to reduce the profiler overhead and collect allocation data only when it is needed (for example, only when working with app functionality you want to profile). Note that memory traffic data will be incomplete in case you turn off collecting allocations at least once during the profiling. Learn more in Analyze Memory Traffic.

  • Get Snapshot by Condition: opens the Get Snapshot by Condition window. Using this window, you can configure dotMemory to automatically get snapshots when a particular condition takes place. Learn more in Getting snapshots by condition.

  • Get Snapshot: gets a memory snapshot for the process selected in the list of processes Pos 1 *. The snapshot is added to the collected snapshot area Pos 4. Getting a snapshot does not interrupt the profiling process, allowing you to get another snapshot (which, for example, can be compared with the first one later). After you finish capturing snapshots, you can proceed to analyzing profiling results.

Profiling multi-process applications

If your standalone or .NET Core application runs more than one process, you can take a memory snapshot of a particular process.

To get a snapshot of a particular process

  1. Start profiling with the enabled Profile child processes profiling option.

  2. After the profiling session starts, select the desired process from the list Pos 1.

  3. Click Get Snapshot.

Viewing real-time profiling data

The timeline graph Pos 3 shows how your app consumes memory in real time. The timeline consists of a number of charts showing:

  • Unmanaged memory: an instant size of unmanaged memory. To add this chart, select the Show unmanaged memory checkbox in Pos 2.

  • Heap generation 0, 1, 2, Large Object Heap (LOH): instant sizes of Gen0, Gen1, Gen2 heaps and Large Object Heap.

  • Allocated in LOH since GC: an instant size of objects that have been allocated to Large Object Heap since the last Garbage Collection (after each GC, the chart restarts from zero). Use this chart to understand when LOH allocations happen (on application startup, during some work, and so on) and how intense they are (for example, the app can have some significant LOH memory traffic that doesn't change the LOH size).

Showing profiling controls in a separate window

You can detach the profiling controls to a separate Profiling Controller window by clicking the Detached pcw button in Pos 2. The controller window is always shown on top of other windows, which is especially helpful on desktops with only one monitor.

Getting snapshots by condition

Sometimes you may be interested in taking snapshots only when a certain condition takes place. The most popular case is taking a snapshot when the memory consumption of your application is dramatically increased. As doing this manually (using the Get Snapshot button) is quite tricky, dotMemory allows you to automate this process. All you need is to set a particular condition and snapshots will be collected automatically after the condition takes place. Currently, the following conditions are supported:

  • Memory consumption increase in MB.

  • Memory consumption increase in %.

  • Period of time in minutes (periodical taking of snapshots).

To enable collecting snapshots by condition

  1. After the profiling session is started, click the Get Snapshot by Condition button in profiling controls.

  2. Select desired conditions in the Automatically get a snapshot section and specify particular values for them:

    • if memory consumption increases by [X] MB- automatically get a snapshot when memory consumption* exceeds the baseline by X MB. The first baseline is a memory consumption on the moment when you click the Start button in the Get Snapshot by Condition window. After the condition takes place, dotMemory gets a snapshot and the memory consumption in that moment becomes a new baseline.

    • if memory consumption increases by [X] %- automatically get a snapshot when memory consumption exceeds the baseline by X percent. The first baseline is a memory consumption on the moment when you click the Start button in the Get Snapshot by Condition window. After the condition takes place, dotMemory gets a snapshot and the memory consumption in that moment becomes a new baseline.

    • if memory consumption exceeds [X] MB- automatically get a snapshot when total memory consumption (absolute value) exceeds X MB.

    • every [X] minutes- automatically get a snapshot every X minutes.

  3. Select the Limit the max number of snapshots to [X] checkbox if you want dotMemory to take no more than X snapshots. This option can be useful if you are limited on the disk space.

  4. Click Start.

To disable collecting snapshots by condition

  1. Click the Get Snapshot by Condition button in profiling controls.

  2. Click Stop.

Last modified: 08 March 2021