For anyone who doesn't mind getting their brain dirty, there is some documentation on how the cache works here[1]. A key point to keep in mind is that the TS cache is a circular buffer, so "full" is a rather vague concept for it. That is, non-stale content can be evicted even if the cache is not technically full.
[1] https://trafficserver.readthedocs.org/en/latest/arch/cache/cache.en.html Tuesday, February 4, 2014, 10:30:36 AM, you wrote: > A related question I have is what would be the best way to determine > if your cache misses are a consequence of otherwise fresh content > being evicted from the cache? That's quite difficult currently. My clients are not overly pleased with that situation either and I am currently working for them on improving the cache API to make this much easier. Hopefully I will be able to present some progress on this at ApacheCon/TS Summit. Because of the way the cache works, it's not really feasible for it to actually know if it is evicting non-stale content. One thing you could do is track cache write bytes and compare that to the total cache size, which should give you a rough estimate of how often the cache wraps. It might be reasonable to put in a specific statistic that counts such wraps. It would be possible to detect an eviction on a cache miss, somewhat reliably. I don't know if that is tracked specifically though.
