On Thu, 26 Jan 2012 12:19:30 +1300 Amos Jeffries wrote: > On 26.01.2012 12:02, RW wrote: > > I noticed today that according to "squidclient mgr:storedir" my > > retention had dropped from 200+ days to 5 days, but all the content > > still seemed to be there. I tried rebuilding swap.state from the > > cache > > files, but it made no difference. > > Under the LRU retention policy the cache age is just a measure of the > oldest file creation timestamp. mtime surely. My assumption was that the linked list in memory was not correctly ordered, and so the head object wasn't the least recently used. > I suspect you had one file up at 200 days and most of the cache under > 5 days. That file recently being erased the retention details drop > immediately to a different oldest entry (added 5 days ago). It isn't, it's 200 days of steady use, and the cache is less than half full, so nothing has been erased. And as I said squid had picked-up all the 200 days worth of content (8GB and 300,000 objects). Actually I did lower the cache size to delete a few hundred MB, and I watched the "cache age" in real-time and it all over the place. > > > > I'm guessing that the rebuild had already been done automatically > > and that when that happens there's no explicit sort to restore lru > > order, it just relies on subsequent access and ageing. Does that > > sound reasonable? > > > > I was wondering, if I wrote bit of script to rename the cache files > > into mtime order could I rebuild swap.state in lru order? > > You could, but it would be of little value. The cache file names and > swap.state order has no bearing on the memory index hash algorithm, > retention policy algorithm, I assumed that part of the point of having a journal was that reading it in sequentially would lru order the queue when squid starts up. Does squid not preserve that information across restarts? > FYI: swap.state is simply a journal of what has been added/removed > from that cache. A "rebuild' is just a dump of the memory index > contents into a fresh empty journal file. Effectively erasing all > records of things removed. I was referring to deleting swap.state when squid isn't running, in which case it's recreated from the cache files.
