Hi Alin, Actually, as it turns out, much of this information is already in the online docs:
http://hc.apache.org/httpcomponents-client-ga/tutorial/html/caching.html http://hc.apache.org/httpcomponents-client-ga/tutorial/html/caching.html#storage Jon On Tue, Mar 20, 2012 at 8:19 AM, Jon Moore <[email protected]> wrote: > Hi Alin, > > Great suggestion - I'll look into updating the documents for the 4.2 > release. > > Jon > > > On Sat, Mar 17, 2012 at 6:51 PM, Vasile Alin <[email protected]>wrote: > >> would be great if http-cache will have these hints in its overview >> documents. >> >> Alin >> >> On 17 March 2012 17:50, Jon Moore <[email protected]> wrote: >> >> > Hi Robert, >> > >> > Naturally, the ultimate answer is: it depends on your scenario! >> However, I >> > can perhaps provide some ways of thinking about your cache >> configuration. >> > >> > First, one of your choices will be which HttpCacheStorage >> implementation(s) >> > you want to use; there are 3 supported in the distribution: >> > 1. an in-memory cache; this is the default implementation if you don't >> > specify an alternative >> > 2. an EhCache backend; this can be used to build a tiered in-memory and >> > on-disk cache, and the on-disk can be configured to persist across >> > application invocations >> > 3. a memcached backend; this can be used either to keep your JVM heap >> size >> > smaller by keeping the cache memory out-of-process, or as a shared >> > memcached pool for a cluster of application servers, for example >> > >> > Now, because the CachingHttpClient is a decorator, you can actually use >> > multiple of these at the same time by wrapping them one inside the >> other. >> > So, for example, you can have a L1 in-memory cache backed by a L2 >> EhCache >> > that spills to disk. >> > >> > In all cases, you will want to be concerned with the total storage >> > resources you want to allocate to the cache; EhCache and memcached have >> > their own configuration for this, but you may want to tweak this for the >> > in-memory cache if that's what you use. One thing to look at is the >> maximum >> > response body size that you'll cache, which currently defaults to 8KB; >> if >> > you plan on caching responses than that, you'll need to increase this >> > setting via CacheConfig#setMaxObjectSizeBytes(). >> > >> > If your server(s) use the 'stale-while-revalidate' Cache-Control >> directive, >> > then you may want to play with >> > CacheConfig#setAsynchronousWorkerIdleLifetimeSecs(), >> > CacheConfig#setAsynchronousWorkersCore(), >> > CacheConfig#setAsynchronousWorkersMax(), and >> > CacheConfig#setRevalidationQueueSize(), all of which basically control >> an >> > underlying thread pool configuration to handle the background validation >> > requests. These have "safe" defaults, so you may not need to tweak these >> > until you get into performance tuning. >> > >> > Finally, if your origin servers don't set proper Cache-Control headers >> but >> > you want to cache the responses anyway, you may want to change >> > CacheConfig#setHeuristicDefaultLifetime(). Another option for this is to >> > write another decorator to modify Cache-Control headers on specific >> > responses that come through, wired up between the CachingHttpClient and >> the >> > "real" underlying HttpClient. >> > >> > That said, if you just drop an unconfigured CachingHttpClient in, for >> say, >> > an API client that gets relatively small, but cacheable responses, you >> > should hopefully see some immediate benefit just from the in-memory >> cache. >> > >> > Hope that helps, >> > Jon >> > >> > On Sat, Mar 17, 2012 at 10:21 AM, Robert Naczinski < >> > [email protected]> wrote: >> > >> > > Hello, >> > > >> > > I want my application use cache, as shown below >> > > >> http://hc.apache.org/httpcomponents-client-ga/tutorial/html/caching.html >> > . >> > > >> > > Does anyone know the best settings or recommendations for the >> > > configuration of the cache? >> > > >> > > Regards, >> > > >> > > Robert >> > > >> > > --------------------------------------------------------------------- >> > > To unsubscribe, e-mail: [email protected] >> > > For additional commands, e-mail: [email protected] >> > > >> > > >> > >> > >
