Welcome to Spotlight on IBM DB2 LUW (Linux, Unix, and Windows). The help topics in this book cover features available in the interface when Spotlight is connected to a version 9 database.
Spotlight is a powerful database monitoring and diagnostic tool. Its unique user interface provides you with an intuitive, visual representation of the activity on the DB2 databases and database partitions that you choose to monitor. Graphical flows and line and fill graphs illustrate the activity on and between database components. Icons display the value of key statistics. Using the Spotlight browser, you can switch your monitoring focus between the various databases and partitions. Additionally, you can view activity at the DB2 instance level for any of these systems.
The power of Spotlight lies in its ability to provide visual and audible warnings if the performance metrics exceed acceptable thresholds. The components and dataflows on the home page change color to show you the source of the problem.
A range of reports and graphs provide you with detailed information about a DB2 database, database partition, or the instance to which the database belongs. This information can be viewed on the screen or be printed.
You can set Spotlight options to warn you when a threshold is reached. You can define a number of thresholds so that warning messages are displayed well before the traffic levels into or out of databases become critical.
Spotlight uses a number of different techniques to warn you when your DB2 instance or a database is exceeding a threshold. For example, to issue a warning, you can configure Spotlight to change a color on the home page or drilldown, provide an audible signal, or perform an action, such as send an email message.
The Details sub drilldown provides additional information for the tablespace selected in the Tablespace Analysis drilldown. The sub drilldown contains two panes:
Tablespace Details pane—This pane shows information such as configuration settings, extent size, and I/O times for a tablespace. When an aggregate tablespace row is selected, the information is for a tablespace as it exists across all database partitions in which it is defined. When an individual tablespace row is selected, the information is for the tablespace as it exists on a certain partition.
Tablespace Partition Information pane—This pane shows information such as size, total number of pages, number of used pages, and number of quiescers. The information is for a tablespace as it exists on a certain database partition. When an aggregate table space row is selected, a "Data only available for partitions" message is shown in this pane.
The Containers tab on the Tablespaces drilldown provides information about the physical storage devices on which the selected tablespace is defined.
The container list provides the following information for each container in a grid format. Since you can choose to hide, display, and rearrange any column in the grid, some columns below might not appear in your current list view, or be in the order they are shown here:
|Name||Name of the device, directory, or file that is the container.|
|Partition||Partition number of the database partition on which the tablespace or buffer pool is defined.|
|ID||Internal identifier of a container.|
|Accessible||Identifies accessible containers.|
Specifies how the container is managed:
|Size||Size of a container in megabytes.|
|Pages||Size of a container in pages.|
Percentage of the container space that the database manager can use to store data.
Note: Each device can have only one container defined. To avoid wasted space, you should make the size of the device and the size of the container equivalent. For example, if the device is allocated with 5000 pages and the device container is defined to allocate 3000 pages, then 2000 pages on the device are not useable.
|File System ID||Unique identifier for a file system.|
|File System Size||Total size of a file system|
|File System Used||Amount of space used on a file system.|
|Stripe Set||Number of the stripe set to which a container belongs.|
The I/O Activity tab on the Tablespace Analysis drilldown provides a summary of I/O activity on the selected tablespace. The graphs show rates for the following:
Reads and writes that use the buffer pool
Direct reads and writes, which do not go through the buffer pool, but access the tablespace directly
The bottom of the drilldown lists average I/O times (in milliseconds) for both buffered and direct reads and writes. The average times are shown in milliseconds.
On the Database Analysis drilldown, you might notice consistently high rates for the following activities on specific databases:
Physical read rates (compared to logical read rates)
Synchronous read or write rates
Direct I/O rates for a database
These high rates might be indications of performance degradation since the activities involve disk I/O and slow-downs in query processing. Use the graphs listed above to pinpoint those tablespaces on which the high I/O activity is occurring.
The following graphs on the I/O Activity tab keep track of the rates for I/O activity on the selected tablespace. These rates are plotted over consecutive monitoring intervals.