A suggestion for the improvement of lease database backend performance
A suggestion for the improvement of lease database backend performance:
Performance suffers in Kea configurations which employ a lease database backen. It is lower than in configurations that use memfile.
This because the penalty incurred by the time taken to update the database. All things being equal it is quicker to update a local file.
As I understand it the protocol demands that lease information be written to disk before ACKing a request.
It is my contention that under "normal" running conditions, on a well configured server that has been active for period of time, the majority of incoming DHCP packets would be either renewals, or reboot discoveries where an active lease may still exist.
To improve lease database backend performance, it would be possible for Kea to write DHCP renewals to a local lease cache file, thereby not breaking the protocol?
This lease cache file could be used to update the database asynchronously, and perhaps by a separate task.
This lease cache file would also be available over reboots.