map reduce become much slower when upgrading from 0.94.11 to 0.96.2-hadoop1

[Li Li]

today I upgraded hbase 0.94.11 to 0.96.2-hadoop1. I have not changed
any client codes except replace 0.94.11 client jar to 0.96.2 's
When with old version. when doing mapreduce task. the requests per
seconds is about 10,000. But with new one, the value is 300. What's
wrong with it?
The hbase put and get is fast and Request Per Second is larger than 5,000

my codes:
List<Scan> scans = new ArrayList<Scan>();
Scan urldbScan=new Scan();
urldbScan.setCaching(5000);
urldbScan.setCacheBlocks(false);
urldbScan.setAttribute(Scan.SCAN_ATTRIBUTES_TABLE_NAME,
HbaseTools.TB_URL_DB_BT);
urldbScan.addFamily(HbaseTools.CF_BT);
scans.add(urldbScan);
Scan outLinkScan=new Scan();
outLinkScan.setCaching(5000);
outLinkScan.setCacheBlocks(false);
outLinkScan.setAttribute(Scan.SCAN_ATTRIBUTES_TABLE_NAME,
HbaseTools.TB_OUT_LINK_BT);
outLinkScan.addFamily(HbaseTools.CF_BT);
scans.add(outLinkScan);
TableMapReduceUtil.initTableMapperJob(scans, Step1Mapper.class,
BytesWritable.class,
ScheduleData.class, job);