Simple Log Service:Flame graph

Background information

A flame graph is used to visualize the performance analysis data of software. Developers can use flame graphs to identify the performance bottlenecks of code and obtain the call relationships and call duration between different functions or code blocks in the code. In a flame graph, a rectangle indicates a method or a function, the width of the rectangle indicates the percentage of the method or function execution time in the total execution time, and the height of the rectangle indicates the depth of the method or function in the call stack. The stacked methods or functions are in the nested relationships.

Procedure

You can add a flame graph on the Data Query or Data Comparison page. For more information, see Data query and Data comparison.

Configurations on the Common Settings tab

On the Common Settings tab, you can configure global settings for the flame graph.

• Parameters in the Basic Configurations section

  Parameter	Description
  Title	The title of the flame graph.
  Show Title	If you turn on Show Title, the title of the flame graph is displayed.
  Show Border	If you turn on Show Border, the borders of the flame graph are displayed.
  Show Background	If you turn on Show Background, the background color of the flame graph is displayed.
  Show Time	If you turn on Show Time, the query time range of the flame graph is displayed.
  Fixed Time	If you turn on Fixed Time, the specified query time range remains unchanged regardless of whether the global time range of the dashboard changes.

• Parameters in the Flame Graph Configurations section

  Parameter	Description
  Display Mode	The display mode of the flame graph. Valid values: Only Flame Graph: displays only the flame graph. Only Table: displays only the table. Table + Flame Graph: displays the table and flame graph.
  Table Retrieval Feature	If the table is displayed and Table Retrieval Feature is turned on, Simple Log Service dynamically adjusts the content of the table and flame graph based on your input.

Interaction with the flame graph

You can click a rectangle in the flame graph to interact with the flame graph. You can zoom in, collapse, expand, or reset the fire graph. You can sort, extend, or retrieve the table. You can also highlight specific rectangles, copy method names and locations, and view value details.

• Zoom in the flame graph

  Click Zoom to expand the width of the selected rectangle to 100%. This allows you to focus on the context of the stack where the method or function resides.

• Collapse or expand the flame graph

  Click Collapse/Expand to collapse or expand the stack bottom. This feature is suitable for scenarios in which the stack depth is large and the stack bottom can be ignored.

• Reset the flame graph

  If you want to restore the flame graph to the original view, click Reset.

• Copy method names and locations

  Click the icon of a method or location to copy the method name or location.

• View value details

  Click or move the pointer over a cell in the table or a rectangle in the flame graph to view the details of the corresponding values.

  The following table describes the value units.

  Category	Unit recorded in data	Unit displayed in the flame graph
  Time	nanoseconds and lock_nanoseconds	s (second), m (minute), h (hour), d (day), M (month), and Y (year)
  Bytes	bytes and inuse_space	bytes, KB, MB, GB, TB, and PB
  Quantity	objects, goroutines, exceptions, and count	Null, K (10^3), M (10^6), B (10^9), T (10^12), and P (10^15)

View mode

The view mode of the flame graph includes the data query view and data comparison view.

Data query view

• Table

  Table header	Description
  Function + Location	The method name and location. The header corresponds to the name field in performance monitoring data.
  Self	The exclusive resource usage of the method, excluding child methods.
  Total	The resource usage of the method, including child methods.

• Flame graph

  The length and percentage of a rectangle in the flame graph are determined by Self and Total. The color of a rectangle in the flame graph is determined by the hash value of Function + Location.

Data comparison view

• Table

  Table header	Description
  Function + Location	The method name and location. The header corresponds to the name field in performance monitoring data.
  Prior	The ratio of the total size of the method to the value of the total method during the previous period of time.
  Current	The ratio of the total size of the method to the value of the total method during the current period of time.
  Diff	The difference between Current and Prior.

• Flame graph

  The length and percentage of a rectangle in the flame graph are determined by Self and Total. The color of a rectangle in the flame graph is determined by Diff. The larger the absolute value of Diff is, the more vivid the color is.

Interaction occurrences

You can configure interaction occurrences in the flame graph to perform drill-down analysis on stacks. This helps you gain a deeper insight into data. You can configure the following interaction occurrences: Open Logstore, Open Saved Search, Open Dashboard, Open Trace Analysis, Open Trace Details, and Create Custom HTTP URL. For more information, see Drill-down events.

By default, interaction occurrences are configured for Query Statement A. For example, you can configure the Open Dashboard interaction occurrence for the flame graph. After you configure the settings, click a point in the flame graph and then click Open Dashboard. You are redirected to the specified dashboard.

When you configure an interaction occurrence, you can add functionName and location as variables to the Filter Statement field. Then, if you click a value of Method + Location in the table or a rectangle in the flame graph, the clicked method name and location are used as the filter condition of the interaction occurrence.