By default, Big Brother records historical data in two sets of files, one in the $BBHIST directory and one in the $BBHISTLOGS directory.
The results of each test are stored in log files in $BBHIST. There are separate logs files for each host.service combination, and a file for each service, containing activity for all hosts.
Each time Big Brother receives a status log, it checks it against the previous status to see if it has changed. If it has, it records the duration of the previous status in the history file for that host and test, and appends a new line with the time stamp of the new status. Here's a sample host.service file:
Sun Jan 24 18:30:45 1999 green 917220645 232068
Wed Jan 27 10:58:33 1999 red 917452713 1560
Wed Jan 27 11:24:33 1999 green 917454273
Notice that last line doesn't have a duration because it is the current status. The duration will be recorded only when the status changes.
Two parameters in bbdef-server.sh control this history logging. If you do not want to keep data in the log files for individual hosts, set BBHOSTHISTLOG=FALSE; not to keep data in the file for all hosts, set BBALLHISTLOG=FALSE. Keep these settings TRUE, the default, to record the history. You can also rename or remove $BBHIST if you do not want to keep any historical data.
You can view the events from the history whenever you view a status log. Click the History button to view the last 50 events for that host.service combination.
You can also use the ext/mkbb/eventlog.sh script to view events for all hosts. By default, it shows the most recent 25 events but you can change that by changing the NUMEVENTS variable in ext/eventlog.sh to the size you want.
The $BBHISTLOGS directory stores the actual results of each test. There is a subdirectory under $BBHISTLOGS for each host; under each host directory there is a subdirectory for each service. Each of these directories stores the status logs for that test.