Re: [infinispan-dev] CHM or CHMv8?

On Fri, Apr 19, 2013 at 12:58 PM, Sanne Grinovero <sanne(a)infinispan.org&gt; wrote: > > On 19 April 2013 10:37, Dan Berindei <dan.berindei(a)gmail.com&gt; wrote: > > Testing mixed read/write performance with capacity 100000, keys 300000, > > concurrency level 32, threads 12, read:write ratio 99:1 > > Container CHM Ops/s 5178894.77 Gets/s 5127105.82 Puts/s > > 51788.95 HitRatio 86.23 Size 177848 stdDev 60896.42 > > Container CHMV8 Ops/s 5768824.37 Gets/s 5711136.13 Puts/s > > 57688.24 HitRatio 84.72 Size 171964 stdDev 60249.99 > > Nice, thanks. > > > > The test is probably limited by the 1% writes, but I think it does show > > that > > reads in CHMV8 are not slower than reads in OpenJDK7's CHM. > > I haven't measured it, but the memory footprint should also be better, > > because it doesn't use segments any more. > > > > AFAIK the memoryCHMV8 also uses copy-on-write at the bucket level, but > > we > > could definitely do a pure read test with a HashMap to see how big the > > performance difference is. > > By copy-on-write I didn't mean on the single elements, but on the > whole map instance: > > private volatile HashMap configuration; > > synchronized addConfigurationProperty(String, String) { > HashMap newcopy = new HashMap( configuration ): > newcopy.put(..); > configuration = newcopy; > } > > Of course that is never going to scale for writes, but if writes stop > at runtime after all services are started I would expect that the > simplicity of the non-threadsafe HashMap should have some benefit over > CHM{whatever}, or it would have been removed already? > Right, we should be able to tell whether that's worth doing with a pure read test with a CHMV8 and a HashMap :)