what does iostat -x say %util and %await is? what does top say cpu is?
does tpstats show non-zero compaction activity? if cpu is not close to 100% try increasing ConcurrentReads since you have plenty of ram, increase the KeysCachedFraction of your CFs to 0.1, 0.2, or even more (until it stops improving performance) -Jonathan On Wed, Jan 20, 2010 at 9:57 AM, envio user <enviou...@gmail.com> wrote: > All, > I downloaded 0.5.0 final and tried following test: > > Machine : Quad Core(64bit) , 8GB RAM, signle node. > > Data model: A single SCF with CompareWith="BytesType" and > CompareSubcolumnsWith="TimeUUIDType" > > Sample data stored: > FF = { > '1' : { > 'ALL' => { > 'TimeUUID1' => '16bytesstring', > ...... > 'TimeUUID25' => '16bytesstring', > } > } > }, > .................... > '100K': { > .............. > } > } > > > Client: PHP > > I loaded with 100K keys with 25 columns per key and value for each of > the sub-column is 16 bytes string. > I populated the data using batch_insert(), and no issues with writes. > For my requirement, I need to fecth all 25 columns. > For this purpose, am using get_slice() method. > Performance of get_slice() is way below our expections. We were > expecting, at least 1000 get_slices/second. "ROW-READ-STAGE" are > piling up. > vmstat and iostat on the machine looks normal. > > nodeprobe -host localhost -port 8080 info > > 69914105239252561041379405595605110341 > Load : 200.9 MB > Generation No : 1263997349 > Uptime (seconds) : 2627 > Heap Memory (MB) : 117.18 / 1023.06 > > I tried to fecth 500 get_slices() per second: > =============================== > > tpstats: > -------- > ROW-READ-STAGE 16 250 94305 > ............. > ROW-READ-STAGE 16 244 112190 > > Load test stats: > > Name | highest 10sec mean | lowest 10sec mean | Highest Rate | > Mean | Count > =============================================================== > request | 48.23 sec | 6.94 msec | 332.6 > / sec | 2.70 sec | 61825 > > Please let me know how can I improve the performance of get_slice(). > > thanks, > -Aita >