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Delegation headaches

Our NFSv4 server gives out read delegations, which allow clients to cache file data and attributes by giving them guarantees they will be notified before a file is changed. But we don't really have any policy for when we give them out--we just hand them out whenever we can. This has a number of consequences, one of which I discovered today: since we don't even have any limits on the number of delegations given out, it's possible to overwhelm the server just by creating a whole bunch of files--the server will dutifully give out a delegation for each one, until the state required for all the delegations exhausts available memory, at which point we get some rather mysterious deadlocks.

Anyway, fixing this all should be interesting work. There's no lack of interesting work at work these days....

The roughly 40-minute (2.5 mile) walk to work is an excuse to enjoy my new toy, the digital music player. So I've walked to and from work both of the last two days. The only thing that makes it a little impractical is traffic noise in the downtown bits. I can't listen to anything with dynamic range without turning it way, way up.