On heavily-loaded web servers with many users making many requests, the access.log file continues to grow in size until it is removed. However, simply removing the file while Apache is running does not fix the issue. You must restart Apache and set up this process to run on a periodic basis.
As Apache states in its Log Rotation documentation, the access log file typically grows 1 MB or more per 10,000 requests. The simplest method to manage this process is to set up a script to run regularly (e.g. weekly or monthly) during off-hours. The script should contain the following lines on a Windows monitoring station:
net stop "up.time web server" del "C:\program files\uptime software\uptime\apache\logs\access.log" net start "up.time web server"
The script runs for a few seconds and the web interface is down for those few seconds before coming back online. No data is lost because the data collector is not touched and only the web interface is temporarily interrupted.