Is message processing single-threaded or are there multiple threads?There are multiple threads performing concurrent operations on both the master and slave.
Can you send me the output from running "db_stat -m" in the environment directory?80MB 1KB 752B Total cache size
Does the frequency change if you increase the cache size?The cache size is fairly static, always has been. I may be able to scratch up a couple of machines to test that. Unfortunately, I wouldn’t be able to upgrade the environment in which this is occurring to 4.8 any time soon.
It is possible for you to test with the newly-released Berkeley DB 4.8?