FB TraceManager 3 - Documentation

Database Monitoring - Header Page Monitoring

Database Monitoring - Header Page Monitoring

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Database Monitoring - Header Page Monitoring

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The Header Page Monitoring facility queries the database header page, which allows you to inspect important base settings like forced writes, page size, page buffers etc. of your database.


New in V3.5: Firebird 3 support has been added.


To start continuous header page monitoring for the connected database, unselect the Paused option
If you want to manually fetch the database header page, click the Refresh button
You can also load the header page data from a file, e.g. when it was created with gstat



Raw Output


The raw output is identical to running gstat -h <database> on the command-line. For example:





Parsed Output


Additionally, FB TraceManager parses the output and adds the result of each header page fetch request into a grid with capabilities to filter, sort data and apply aggregations in the grid footer per-column.




This makes it easy to read and furthermore, FB TraceManager also provides "derived" attributes, like the gaps/differences between the various transaction counters as shown above in the OIT_AT, OIT_OST, OIT_NT, OAT_OST, OAT_NT and OST_NT columns. A customizable color management facility, with meaningful default-settings, underlines suspicious database settings (e.g. Forced Writes = OFF etc.).


A grid context-menu item Locate OAT in Monitoring Tables allows you to take the OAT of the last added row and applies a regular expression filter on the MON$TRANSACTION_ID column in the Transactions monitoring table tab. This functionality is only available in the Enterprise Edition, because Monitoring (MON$) Tables integration is part of the Enterprise Edition only.


New in V3.0: A new SEVERITY column has been added, which gets automatically filled with various levels, in case something suspicious has been detected. This new information also gets persisted in the database.



Parsed Output Storage


If you wish, the parsed output can be persisted in the FBTM3.fdb database in a table called HEADER_PAGE_DATA_PARSED. This allows you to query/inspect header page data at a later point in time. To enable parsed output storage, you have to select the Log to database option in the Settings flyout tool panel. A Commit Interval defines the number of records when a database commit should happen. With a click on the Commit Now button, you immediately can persist the uncommitted parsed output records in the FBTM3.fdb database.



Customization and Settings


The header page monitoring module is highly customizable. Simply click the Settings flyout tool panel to get in touch with various options.




The various settings are more or less self-explanatory. Use the Notify Only When Changed option if you wish that not each header page fetch request is visualized automatically, independent on whether the header page has changed or not. There is a similar setting Log Only When Changed available, which is used for parsed output storage.


The user-definable colors on various header page data gives you a way to spot questionable conditions more easily.


Changed settings are stored and re-loaded every time you open the database monitoring area when connecting to a database.



See also

Register Project

Database Monitoring

Database Monitoring - Database Statistics Monitoring

Database Monitoring - Monitoring (MON$) Tables