Shulou(Shulou.com)06/01 Report--

HBASE implements second-level Index based on coprocessor

The scenario is as follows: store UC_TWEETS table, ROWKEY design: folderId_dayId_siteId_docId, export has the following requirements: export according to campaignId, so you need to store the index table of campaignId

The implementation steps are as follows:

First, the code is implemented as follows:

Public class HbaseCoprocessor extends BaseRegionObserver {

@ Override

Public void prePut (final ObserverContext e, final Put put

Final WALEdit edit, final Durability durability) throws IOException {

Configuration configuration = HBaseConfiguration.create ()

Configuration.set ("hbase.regionserver.lease.period", "900000")

Configuration.set ("hbase.rpc.timeout", "1800000")

Configuration.set ("hbase.client.scanner.timeout.period", "1800000")

Configuration.set ("hbase.zookeeper.property.clientPort", "2181")

Configuration.set ("hbase.zookeeper.quorum", "DEV-HADOOP-01,DEV-HADOOP-02,DEV-HADOOP-03")

Configuration.set ("hbase.master", "DEV-HADOOP-01:60000")

HTable table = new HTable (configuration, "UC_INDEX")

List kv = put.get ("F1" .getBytes (), "campaignId" .getBytes ())

Iterator kvItor = kv.iterator ()

While (kvItor.hasNext ()) {

KeyValue tmp = (KeyValue) kvItor.next ()

String rowkey = new String (tmp.getRow ())

String value = new String (tmp.getValue ())

String newRowkey = value + "_" + rowkey

Put indexPut = new Put (newRowkey.getBytes ())

IndexPut.add ("F1" .getBytes (), tmp.getQualifier (), tmp.getValue ())

Table.put (indexPut)

}

Table.close ()

}

}

Second, export the above HbaseCoprocessor class. Select Export-> Jar File to export to a ucTweet.jar file

Third, upload the ucTweet.jar file to HDFS with the following command:. / hadoop fs-put / data/server/ucTweet_index.jar / jars

4. Set the coprocessor attribute of the UC_TWEETS table. The command is as follows: alter 'UC_TWEETS',METHOD= >' table_att','coprocessor'= > 'hdfs://192.168.9.110:9000/jars/ucTweet.jar | com.prime.dsc.inputservice.coprocessor.HbaseCoprocessor | 1001 |'

Fifth, insert the data into the UC_TWEETS table. If the UC_INDEX table also has data and conforms to the design, the secondary index is established successfully.

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