Yes , I thought about large number , so you said it depends on block size. Good point.
I have one recored ~ 4k , block size is: <property> <name>dfs.block.size</name> <value>268435456</value> <description>HDFS blocksize of 256MB for large file-systems. </description> </property> what is the number that I have choose? Assuming I am afraid that using number which is equal one block brings to socketTimeOutException? Am I write? Thanks Oleg. On Thu, Nov 11, 2010 at 1:30 PM, Friso van Vollenhoven < fvanvollenho...@xebia.com> wrote: > How small is small? If it is bytes, then setting the value to 50 is not so > much different from 1, I suppose. If 50 rows fit in one block, it will just > fetch one block whether the setting is 1 or 50. You might want to try a > larger value. It should be fine if the records are small and you need them > all on the client side anyway. > > It also depends on the block size, of course. When you only ever do full > scans on a table and little random access, you might want to increase that. > > Friso > > > > > On 11 nov 2010, at 12:15, Oleg Ruchovets wrote: > > > Hi , > > To improve client performance I changed > > hbase.client.scanner.caching from 1 to 50. > > After running client with new value( hbase.client.scanner.caching from = > 50 > > ) it didn't improve execution time at all. > > > > I have ~ 9 million small records. > > I have to do full scan , so it brings all 9 million records to client . > > My assumption -- this change have to bring significant improvement , but > it > > is not. > > > > Additional Information. > > I scan table which has 100 regions > > 5 server > > 20 map > > 4 concurrent map > > Scan process takes 5.5 - 6 hours. As for me it is too much time? Am I > write? > > and how can I improve it > > > > > > I changed the value in all hbase-site.xml files and restart hbase. > > > > Any suggestions. > >
