If the lifespan of a process is smaller than an expiry cycle then it may not trigger the expiry process often enough. We mitigate this a little bit by pre-filling the counter with a random number, but that means that on average a process still needs to survive for half an expiry cycle.
Instead lets trigger expiry randomly, but keep the same overall frequency. This will always give us an expiry rate proportional to the number of writes whatever the process length.
If the lifespan of a process is smaller than an expiry cycle then it may not trigger the expiry process often enough. We mitigate this a little bit by pre-filling the counter with a random number, but that means that on average a process still needs to survive for half an expiry cycle.
Instead lets trigger expiry randomly, but keep the same overall frequency. This will always give us an expiry rate proportional to the number of writes whatever the process length.
Fixes #91