CLFS (Common Log File System)

Question

Hi,
I am using windows CLFS, but I think I may have some bugs in its usage. I want to see if multiplexed logs have any benefit over dedicated logs when after each record write, the record is flushed into the disk. When I create multiplexed log files, the time
it takes to complete a flushed append, is below one mili second, which does not make sense. When creating a dedicated log file however, the write takes about 3 mili seconds. I wonder if this makes sense or if not what maybe the write way of forcing flushes.
Thanks.

Answer 1

Hi Paris84,
Common Log File System supports dedicated logs and multiplexed logs. A dedicated log has a single stream of log records that is used by all of the log's clients. A multiplexed log (also called a common log) has several streams.
Here are the links for reference:
Dedicated CLFS Logs
http://msdn.microsoft.com/en-us/library/windows/hardware/ff542996(v=vs.85).aspx
Multiplexed CLFS Logs
http://msdn.microsoft.com/en-us/library/windows/hardware/ff556410(v=vs.85).aspx
To force the flush, there are two functions in the Common Log File System. They are FlushLogBuffers function and FlushLogToLsn function.
Here are the links for reference:
FlushLogBuffers function
http://msdn.microsoft.com/en-us/library/windows/desktop/bb540375(v=vs.85).aspx
FlushLogToLsn function
http://msdn.microsoft.com/en-us/library/windows/desktop/bb540376(v=vs.85).aspx
If you are developing an application and have any further issues in the future, you may need to post the issue in the MSDN forum.They are more professional in this area.
https://social.msdn.microsoft.com/Forums/en-US/home
Best regards