count hbase java_HBase协处理器统计表数据量

1.Java代码实现

importorg.apache.hadoop.hbase.client.coprocessor.AggregationClient;importorg.apache.hadoop.hbase.client.coprocessor.LongColumnInterpreter;importorg.apache.hadoop.hbase.coprocessor.AggregateImplementation;/***

* 协处理器统计HBase表数据量

*

**/

public classHBaseRecordsCounter {/*** HBase API添加协处理器

**/

public static voidaddCoprocessor(Configuration conf, String tableName) {try{

byte[] tableNameBytes = Bytes.toBytes(tableName);

HBaseAdmin hbaseAdmin = new HBaseAdmin(conf);

HTableDescriptor htd = hbaseAdmin.getTableDescriptor(tableNameBytes);

if (!htd.hasCoprocessor(AggregateImplementation.class.getName())) {

hbaseAdmin.disableTable(tableNameBytes);

htd.addCoprocessor(AggregateImplementation.class.getName());

hbaseAdmin.modifyTable(tableNameBytes, htd);

hbaseAdmin.enableTable(tableNameBytes);

}

hbaseAdmin.close();

}catch(MasterNotRunningException e) { e.printStackTrace(); }catch(ZooKeeperConnectionException e) { e.printStackTrace(); }catch(IOException e) { e.printStackTrace(); } }/*** 统计表数量 **/

public static voidexeCount(Configuration conf, String tableName, String family) {try{//使用hbase提供的聚合coprocessor

AggregationClient aggregationClient = newAggregationClient(conf); Scan scan= newScan();//指定扫描列族，唯一值

scan.addFamily(Bytes.toBytes(family));long start =System.currentTimeMillis();long rowCount = aggregationClient.rowCount(TableName.valueOf(tableName), newLongColumnInterpreter(), scan); System.out .println("Row count: " + rowCount + "; time cost: " + (System.currentTimeMillis() - start) + "ms"); }catch(Throwable e) { e.printStackTrace(); } }public static voidmain(String[] args) { String tableName= "test"; Configuration conf= newConfiguration(); conf.set("hbase.zookeeper.quorum", "host1,host2,host3"); conf.set("hbase.rootdir", "hdfs://host:8020/hbase");//提高RPC通信时长

conf.setLong("hbase.rpc.timeout", 600000);//设置Scan缓存

conf.setLong("hbase.client.scanner.caching", 1000);addCoprocessor(conf, tableName);exeCount(conf, tableName,"info"); } }

2. 启用协处理器

启用协处理器方法1.

启动全局aggregation，能过操纵所有的表上的数据。通过修改hbase-site.xml这个文件来实现，只需要添加如下代码：

hbase.coprocessor.user.region.classes

org.apache.hadoop.hbase.coprocessor.AggregateImplementation

启用协处理器方法2.

hbase shell添加coprocessor:

disable ‘member’

alter ‘member’,METHOD => ‘table_att’,’coprocessor’ => ‘hdfs://master24:9000/user/hadoop/jars/test.jar|mycoprocessor.SampleCoprocessor|1001|’

enable ‘member’

hbase shell 删除coprocessor:

disable ‘member’

alter ‘member’,METHOD => ‘table_att_unset’,NAME =>’coprocessor$1′

enable ‘member’