Posted by Barbara Brazil on February 26, 2004 at 14:30:02:
In Reply to: Flushing CometServe's Cache posted by Robert G Laurin on February 25, 2004 at 14:34:11:
Robert:
I have studied and tested the flushing algorithm for CometServe. Here's a summary of what goes on:
Anytime a record is either written to or deleted from a file a flag is set to indicate that the file needs to be flushed. There is a separate thread running that checks the file list continuously to see if a file has been marked for flushing. Based on this alone, an updated file will be flushed once per hour.
In addition, any time a file is closed by any user a priority flush flag is set. Open files are checked for this flag in another loop every second. The next file in the list with the flag set is flushed then. A file that has been closed by a user but is still open by others will be flushed in this loop after at most 1060 seconds or about 17 minutes. So your file could be flushed after as little as 1 second (if only one file was marked in this manner) or after roughly 17 minutes if the max of 1000 files were open and all were marked for priority flushing.
I suspect the timing of this algorithm was designed to provide flushing with minimal impact on system performance. We wouldn't mind experimenting with changes to the frequency of flushing. We have a couple of ideas we'd like to try. Would you be willing to run a test version of the NLM that would force flushing more frequently and report back any change in performance?
bb