In order to prepare an allocation call tree, you have to click on the
calculate toolbar button
or choose View->Calculate allocation call tree from JProfiler's
main menu. If an allocation tree has already been calculated, the context sensitive menu
also gives access to this action.
Before the allocation call tree is calculated, the allocation options dialog is shown. The class or package selection as well as the selected liveness mode are displayed at the top of the allocation call tree view.
If URL splitting is enabled,
each request URL creates a new node with a
special icon and the prefix
URL:, followed by the part of the request URL on which the allocation call tree
was split. Note that URL nodes group request by the displayed URL.
You can disable both Java EE component detection as well as URL splitting on the Java Subsystems tab of the profiling settings. Also, the URL splitting method can be customized in the profiling settings or with a custom handler in the profiling API.
When you switch between two aggregation levels, JProfiler will make the best effort to preserve your current selection. When switching to a a more detailed aggregation level, there may not be a unique mapping and the first hit in the allocation call tree is chosen.
The allocation call tree doesn't display all method calls in the JVM, it only displays
Runnable.run()
and the main method are always displayed, regardless of
the filter settings.
A particular node is a bridge node if it would normally not be displayed in the view, but has descendant nodes that have to be displayed. The icons of bridge nodes are grayed out. For the allocation call tree view this is the case if the current node has no allocations, but there are descendant nodes that have allocations.
To quickly expand larger portions
of the allocation call tree, select a method and choose
View->Expand Multiple Levels from the main window's menu or
choose the corresponding menu item from the context menu. A dialog is shown
where you can adjust the number of levels (20 by default) and the threshold in per mille
of the parent node's value that determines which child nodes are expanded.
If you want to
collapse an opened part of the allocation call tree, select the
topmost method that should remain visible and choose
View->Collapse all from the main window's menu or
the context menu.
DEL
key
or by choosing Hide Selected from the context menu. Percentages will be corrected accordingly as if the
hidden node did not exist.
All similar nodes in other call stacks will be hidden as well.
When you hide a node, the toolbar and the context menu will get a Show Hidden
action. Invoking this action will bring up a dialog where you can select hidden elements to be shown again.
Each rectangle represents a particular call stack. The area of the rectangle is proportional to the length of the percentage bar in the tree view. In contrast to the tree, the tree map gives you a flattened perspective of all leafs in the tree. If you're mostly interested in the dominant leafs of the call trees, you can use the tree map in order to find them quickly without having to dig into the branches of the tree. Also, the tree map gives you an overall impression of the relative importance of leaf nodes.
By design, tree maps only display values of leaf nodes. Branch nodes are only expressed in the way the leaf nodes are nested. For non-leaf nodes which have significant inherent values, JProfiler constructs synthetic child nodes. In the diagram below, you can see that node A has an inherent value of 20% so that its child nodes have a sum of 80%. To show the 20% inherent value of A in the tree map, a synthetic child node A' with a total value of 20% is created. It is a leaf node and a sibling node of B1 and B2. A' will be shown as a colored rectangle in the tree map while A is only used for determining the geometric arrangement of its child nodes B1, B2 and A'.
The tree map is shown up to a maximum nesting depth of 25 levels. The depth of the call stack of a particular leaf in the tree map is encoded in its color. The color scale blends blue into yellow, where blue indicates a smaller and yellow a larger depth. The scale is always relative to all currently displayed nodes. For example, if you zoom into a particular area of the tree map, the scale will be re-adjusted so that that the depth of the parent node corresponds to blue. Below the tree map, a legend presents all possible colors as well as the displayed maximum and minimum depths.
Double-clicking on any colored rectangle in the tree map will zoom to the parent node unless the node is
already a top-level node. There are tool bar actions for for
zooming in and
zooming out, as well as as context actions for
showing the actual root of the allocation call tree.
In order to explore the hierarchical environment of a particular leaf in the tree map, there is a context action "Show In Tree", that switches to the tree view mode and selects the same node there.
Note that the line number shows the line number of the invocation and not of the method itself.
The size and the allocation count are either cumulated for all calls below the associated node or not, depending on the corresponding cumulation view setting. Note that allocations performed in calls to filtered classes are consolidated in the first call into a filtered class.