Heatmaps
Heatmap is a technique for visual representing data, in which area and color of rectangles represent two different metrics, for example, database table’s storage size and I/O activity level. Heatmap also uses nested rectangles to represent hierarchical relationships, for example, tables residing in a dbspace, or user sessions originated from the same host computer. Heatmaps provide significant advantage over tabular data in monitoring application due to their ability to integrate multiple dimensions of information. DBAs can easily answer questions, like which large tables are highly fragmented or which user sessions consume a lot of memory and at the same time were opened a long time ago.
Server Studio enables building heatmaps in IDS server storage and user activity domains.
Using Heatmaps for troubleshooting of performance problems
You can use Heatmaps for a troubleshooting of performance problems by applying Auto-Refresh and logging facilities of this component. For example, during peak load time of the IDS server you can setup heatmap to record at specified rate an information about 10 top (or N-top) user sessions that create most of I/O activity or consume most of memory. You can also collect the information about N-top tables that provide most of I/O activity during this time. Using collected log of most resource consuming users and tables, you can deduct which application creates most performance problems or which tables need to be re-organized to reduce system resource consumption.
To enable collecting and recording heatmap data, press Set Auto-Refresh Options button in either Storage or Session Heatmap panel and specify the logging file name and refresh interval. Check ‘Refresh diagram automatically’ and ‘Log Collected Data to File’ checkboxes and press OK button.
To turn off the auto-refresh operation, press Set Auto-Refresh Options button on a Heatmap panel, uncheck ‘Refresh diagram automatically’ and press OK button.
Storage Heatmap
Storage heatmap displays rectangular representations of database tables and indexes, in which you can choose two parameters representing rectangular area and color. Available parameters include table data size, number of table extents, I/O activity, number of locks, etc. You can also choose how to group tables in a heatmap. The grouping options include ability to group by dbspace or database. For example, if grouped by dbspace and rectangular area parameter represents table data size, the entire group rectangular area represents total data size of all tables in this dbspace.
You can view storage heatmap in Storage Properties panel as well as to open it as a separate document panel.
To view Storage heatmap as part of Storage properties view, select Storage node in the Object Explorer and choose Properties from popup menu. Then click on Heatmap tab in the Properties panel.
Each rectangle represents a table or index.
You can easily choose which parameters to use for a size and color of rectangles using dropdowns located at the top of heatmap panel. Default parameters are Data Size for rectangle size and Number of Extents for a color. You can also choose how to group objects – by DBSpace (default option) or by Database – using Group By dropdown located next to Color range.
Color range by default is defined automatically, by dividing a range from the smallest number for the color’s selected parameter to a largest number into 16 colors. You can change this default behavior by using Configure menu from a right mouse menu.
Viewing Object Details
To see object’s details, simply hover a mouse over the rectangle. The tooltip will show the selected table or index basic information relevant to a heatmap. You can use right mouse Properties menu to navigate to the selected object properties panel to see all object’s details.
When you hover a mouse over a group header, such as dbspace header or database header, the tooltip will show aggregated information for a group, for example, total size of objects in a group or total I/O activity in the group.
Zooming In
You can zoom in to a single group so that the heatmap shows only objects from one dbspace or one database. Just double-click on the group header rectangle to zoom into this group.
To Zoom Out, choose Zoom Out from popup menu.
Setting Object Filters
You can set filters on groups (dbspaces or databases) or individual objects (tables and indexes).
To set a filter, click on a heatmap and choose Filters from right mouse menu or click on Filters tab in Heatmap Options dialog box.
User Sessions Heatmap
Sessions heatmap displays rectangular representations of user sessions, in which you can choose two parameters representing rectangular area and color. Available parameters include connection time, memory size, I/O activity, number of locks, etc. You can also choose how to group sessions in a heatmap. The grouping options include ability to group by user login name or host from where sessions are orihinated. For example, if grouped by user and rectangular area parameter represents locks, the entire group rectangular area represents total number of locks created by all sessions of this user.
You can view sessions heatmap in Sessions Properties panel as well as to open it as a separate document panel.
To view Sessions heatmap as part of Sessions properties view, select Sessions node in the Object Explorer and choose Properties from popup menu. Then click on Heatmap tab in the Properties panel.
Each rectangle represents an user sessions.
You can easily choose which parameters to use for a size and color of rectangles using dropdowns located at the top of heatmap panel. Default parameters are Memory Size for rectangle size and I/O Activity for a color. You can also choose how to group objects – by User (default option) or by Host – using Group By dropdown located next to Color range.
Color range by default is defined automatically, by dividing a range from the smallest number for the color’s selected parameter to a largest number into 16 colors. You can change this default behavior by using Configure menu from a right mouse menu.
Viewing Object Details
To see object’s details, simply hover a mouse over the rectangle. The tooltip will show the selected session basic information relevant to a heatmap. You can use right mouse Properties menu to navigate to the selected object properties panel to see all object’s details.
When you hover a mouse over a group header, such as user header or host header, the tooltip will show aggregated information for a group, for example, total memory of objects in a group or total I/O activity in the group.
Zooming In
You can zoom in to a single group so that the heatmap shows only objects from one user or one host. Just double-click on the group header rectangle to zoom into this group.
To Zoom Out, choose Zoom Out from popup menu.
Setting Object Filters
You can set filters on groups (users or hosts).
To set a filter, click on a heatmap and choose Filters from right mouse menu or click on Filters tab in Heatmap Options dialog box.