random access slowly when writing new data to hTable, how to optimize?

[刘京磊]

hadoop version:  0.20.2
hbase version: 0.20.6

1 master , 7 slaves/regionservers : 4cpus, 34G memory   hbase heap size: 15G
3 zookeepers: 2cpus, 8G memeory

now, there are 1573 regions(about 1T). It spends 10ms-200ms when random
accessing if not writing.

We need to put 200G data (about 0.4billion rows) at a time. It maybe spend
20+s when random accessing.

code like this:

HTablePool tablePool = new HTablePool(config, 20);
HTable table = tablePool.getTable("productDB");
table.setWriteBufferSize(1024*1024*24);
List<Put> puts = new ArrayList<Put>();

while(true){
  Put put = new Put(Bytes.toBytes(id));
  put.add(...);
  put.setWriteToWAL(false);
  puts.add(put);

  if(rows % 1000 == 0){
    table.getWriteBuffer().addAll(puts);
    table.flushCommits();
    puts.clear();
  }
}


Thanks for any help

-- 
Derek Liu