Monitoring data (.dat) files

Event data generated by monitoring alarms are stored in .dat files. This data can be used for debugging and analysis.

The GAS writes monitoring data to monitoring data (.dat) files in the monitoring directory. When an event triggers an alarm, the GAS creates the required monitoring data file to store the event data. The filename is in the format YYYYMMDD-hhmmss.dat, based on the date and the time the first write takes place.

Dat file structure

A .dat file is a raw file type. When converted to human-readable form, the data is structured under column headings that appear in the first row. Take a look at sample data fetched from a monitoring data file:
The first row shows the column headings. Each subsequent row shows these entries:
  1. EVENT: The name of the event. This corresponds to the name of the alarm raised, for example REQUEST_ERROR, DVM_CRASH, and so on.
  2. REQID: The HTTP request id (REQID), as recorded in the GAS logs.
  3. VALUE(ms): This field depends on the event; it can be a number or a time (in milliseconds).
  4. TIMESTAMP(s): The elapsed time in milliseconds since 1970.

To see the data visually in graph form, import the fetched monitoring data into a Microsoft® Excel™ spreadsheet.

Fetch data

Use the gasadmin monitoring fetch command to transfer data to a spreadsheet, database, or third party monitoring system that manages and processes the monitoring data. Once you fetch the monitoring data, the GAS removes the monitoring data (.dat) file.

Manage monitoring data files

Depending on the monitoring level set, monitoring data files can grow quickly and you can end up with very large files. You should have a plan for archiving and removing monitoring data files, similar to the recommendations for log files . As mentioned previously, fetching monitoring data removes the associated monitoring data file. You can also remove monitoring data files by hand using the gasadmin monitoring clean command.