Le 7 déc. 2011 à 21:05, Paul Libbrecht a écrit : > I can use the StatisticListenerImpl which gives fairly high numbers: >> StatisticListenerImpl: Hit = 9583563 / 1320251374, stale hit = 0 / 538, miss >> = 8541 / 17175236, flush = 27348, entries (added, removed, updates) = >> 25457741, 0, 7678101 > these numbers are integers, and might actually be too small for the 2billions > limit of an int, they are static (so count "all the OSCache instances").
And it did spin to negative already several times. How delicious! > What I would like to get is the "eviction rate" but I do not know how to > compute it. > That is, I wish to read the number of cache-entries which are thrown away > because the cache is full and others come in. I simply counted differences between snapshots the number of adds minus the capacity. If the caches are full (which is the case after about 2 minutes after starting curriki), this gives a faithful estimate. Until the number of adds becomes negative ;->. > Once I can have it, I can start tuning (cache size, less greedy algorithms, > ...) and measure the effect of such tuning. We have plenty of RAM space to > accommodate the cache but we should use this well. Well, we just had a restart because the appserv was sweating 1700% and had 23 threads executing the same place: at com.opensymphony.oscache.base.Cache.dispatchCacheMapAccessEvent(Cache.java:907) (somewhere behind a getFromCache) Trying to understand what would have caused this, I could not understand it. > The big annoyance with this process is that it can only run on our production > server. So thus far I did not dare register a CacheListener in groovy fearing > it would suddenly be slow. Can anyone state me a danger of doing so? > Has anyone used a different strategy or tool? I've discovered that Zabbix would have a time-synched view (or close to it). Did anyone try Zabbix with XWiki? Indeed Vincent, that would leverage JMX so it could be used directly for XWiki. Can the eviction-rate be computed with this? I was surprised to find the tool-set of OSCache's statistics quite meager. > I'm happy to post my little monitor script. The cache monitor is here: http://www.curriki.org/xwiki/bin/view/CurrikiCode/CacheMonitor (publicly accessible) with the stats disabled. thanks in advance Paul _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
