db2Gdba
Part 1
This section describes the db2Gdba functionality. For tips on how to better use the application, and quickly retrieve useful information go to the tip session.
Note: Marked records or marked objects in this document refer to records in a grid with the check-box column checked. To check/uncheck records, click on the check box or press the space bar. Selected record or selected object refers to the one with the active focus.
Tab Snapshots
Tab Applications.
Click Refresh to retrieve the list of applications currently connected to the database.
This list shows applications currently connected to the database. Optionally, you can select to display only active sessions (default). Active sessions are considered those with status:
BACKUP
COMMIT_ACT
COMP (Compiling)
CONNECTPEND
INTR (Request Interrupted)
IOERROR_WAIT
LOAD
LOCKWAIT
QUIESCE_TABLESPACE
RECOMP
REMOTE_RQST
RESTORE
ROLLBACK_ACT
ROLLBACK_TO_SAVEPOINT
TPREP (preparing a transaction)
UNLOAD
UOWEXEC
WAITFOR_REMOTE
To display only the running background processes, check “Show Only Background Processes” check-box.
For any selected application you can display the Statements, and the Application Snapshot. If the application status is LOCKWAIT, you can investigate the lock chain of applications and their statements. Finally, you can force applications off the database if necessary. The figure below shows the application snapshot taken when several processes were in lock-waiting state.
To get the lock chain of any application in lock-wait state, select it and click Lock chain (see figure below).
Important Note about forcing Applications or Activities: The db2Gdba utility provides interfaces to quickly, with a few mouse clicks, connect to a database, see what processes are running, see their execution state, see how they are performing, see who is causing issues like locking other applications, and finally: take action.
The actions you take may depend on many factors. db2Gdba offers functionality to investigate issues that you can fix after the facts. However, there are occasions when you have no time for investigation, and the only way to make your company SLA, for instance, is to force the application , which is not part of your SLA, and is blocking the one which is.
Always keep in mind that forcing application id's can lead to huge rollback operations, especially in large data warehouses. Always use Force Application or Cancel Activity with extreme caution.
As this figure suggests, the application id 48066, in executing state, is blocking application 24832. You also see the statement the blocking application is running in real time.
The Utilities button found on this tab shows the currently running db2 utilities in a separate window. The figure below shows this interface captured at the moment an online database backup was running.
Click Statements to see all the statements for a given running application. This window shows all the columns from the statement snapshot table function (see figure below). This information is helpful to investigate process performance, and to track the progress of your statements in real time. All statements involved in the application are shown. Some boxes in this window separate parameter values for different statements of the same application using a pipe “|”. Other boxes show the aggregated values (see Total Rows Read and Written in the figure below).
You can mark multiple records (applications) to force all of them off at once clicking Force App.
Tab Activities.
Shows process information similar to the applications tab (figure below).
Activities are controlled by the Workload management (WLM) subsystem. Here you can see additional detail of your running processes like their nesting levels, and more.
Despite forcing applications off, when you cancel activities, the applications are not disconnected from the database. In multi partitioned environments you can search on activities running in specific database partitions
Database.
Provides a complete database snapshot. In this window you can find the total allocated and used disk space of the database.
Log Utilization.
This tab shows the database log detailed snapshot, including the application ID holding the oldest transaction. The database log utilization is displayed in a bar showing the progress of the current log usage and top log usage versus log allocated. In multi-partitioned environments, each bar represents a database partition log. They are shown in descending order by log utilization. This way, one can quickly detect, in real time, if any transaction may be causing a data skew, or if any database partition log is about to get full. You may also consider using the "used top" values to follow up the overall database log utilization.
Members.
Shows one record per database member. This grid displays allocated, used, and free space for all members of the database. It shows only one record in one-partitioned systems.
History.
Displays the history of the database. This interface is used to look up for events logged in the database
history file. You can filter by type of objects, operations, and database partition. Even though the database history can be retrieved for a specific time interval, it is recommended to prune the history file at a frequent basis. This maintains this file short and efficient.
HADR. (Available only for db2 versions 10.1 on)
Available only for databases in HADR mode. It provides a complete snapshot of the HADR status. This tab is the only o neavailable if you connect to a standby database having the db2 parameter "read on standby enabled" set to YES (see figure below).
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