Memory is also a big consideration.. We've taken to running Derby using the network connector in a separate JVM entirely running as a daemon/service, which gives a number of benefits including exclusive rights to memory and the ability to connect to the database on a test or live system and run queries..
-Ron On Apr 9, 2010, at 9:59:59 AM, Kristian Waagan wrote: > On 09.04.2010 10:39, Rajesh Datla wrote: >> Hi All, >> I like to know the performance utilization of multi-processors >> on a machine by Derby 10.3. Does Derby 10.3 utilize all CPU's on 8 CPU >> machine?. >> > > Hi Rajesh, > > I cannot give you any hard numbers for 10.3, but I have some general > comments. Hopefully someone else can pitch in with more details. > > First, a fair bit of performance / scalability work has been done since 10.3. > The community is in the process of preparing for the 10.6 release [1]. I > would strongly suggest you use a newer release if possible. > > Further, how much of the CPU Derby can utilize depends heavliy on the load, > with factors such as: > - number of concurrent connections / queries > - data contention > - access pattern > - IO subsystem (plus read/write ratio and page cache tuning ) > > The Derby engine is multi-threaded and should be able to use the available > CPUs when / if required. To find out the utilization rate you have to run a > test with your app / load. > Note that a single query will only use a single CPU / core. > > I have run an industry standard benchmark on a 32-core machine, and Derby is > able to utilize the CPUs fairly well with that specific load and > configuration (75+%). > I have also seen syntetic benchmarks utilizing around 99% of the CPU (all > data in memory, read only, no data contention), but I doubt you'll manage > that in a real-world app :) > And finally, Derby has to use the CPUs for something useful as well - I'd > recommend a load test to see if Derby fulfills your requirements (then you > can come back to the list and ask questions if you see unexpected results). > > > Regards, > -- > Kristian > > [1] http://wiki.apache.org/db-derby/DerbyTenSixOneRelease > >> Regards >> Raj > >
