org.apache.beam.sdk.io.hcatalog

Class HCatalogIO

java.lang.Object

org.apache.beam.sdk.io.hcatalog.HCatalogIO

@Experimental(value=SOURCE_SINK)
public class HCatalogIO
extends java.lang.Object

IO to read and write data using HCatalog.

Reading using HCatalog

HCatalog source supports reading of HCatRecord from a HCatalog managed source, for eg. Hive.

To configure a HCatalog source, you must specify a metastore URI and a table name. Other optional parameters are database & filter. For instance:

 Map<String, String> configProperties = new HashMap<>();
 configProperties.put("hive.metastore.uris","thrift://metastore-host:port");

 pipeline
   .apply(HCatalogIO.read()
       .withConfigProperties(configProperties)
       .withDatabase("default") //optional, assumes default if none specified
       .withTable("employee")
       .withFilter(filterString) //optional, may be specified if the table is partitioned
 

HCatalog source supports reading of HCatRecord in an unbounded mode. When run in an unbounded mode, HCatalogIO will continuously poll for new partitions and read that data. If provided with a termination condition, it will stop reading data after the condition is met.

 pipeline
   .apply(HCatalogIO.read()
       .withConfigProperties(configProperties)
       .withDatabase("default") //optional, assumes default if none specified
       .withTable("employee")
       .withPollingInterval(Duration.millis(15000)) // poll for new partitions every 15 seconds
       .withTerminationCondition(Watch.Growth.afterTotalOf(Duration.millis(60000)))) //optional
 

Writing using HCatalog

HCatalog sink supports writing of HCatRecord to a HCatalog managed source, for eg. Hive.

To configure a HCatalog sink, you must specify a metastore URI and a table name. Other optional parameters are database, partition & batchsize. The destination table should exist beforehand, the transform does not create a new table if it does not exist. For instance:

 Map<String, String> configProperties = new HashMap<>();
 configProperties.put("hive.metastore.uris","thrift://metastore-host:port");

 pipeline
   .apply(...)
   .apply(HCatalogIO.write()
       .withConfigProperties(configProperties)
       .withDatabase("default") //optional, assumes default if none specified
       .withTable("employee")
       .withPartition(partitionValues) //optional, may be specified if the table is partitioned
       .withBatchSize(1024L)) //optional, assumes a default batch size of 1024 if none specified
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HCatalogIO.Read A PTransform to read data using HCatalog.
static class	HCatalogIO.Write A PTransform to write to a HCatalog managed source.

Method Summary

Modifier and Type	Method and Description
static HCatalogIO.Read	read() Read data from Hive.
static HCatalogIO.Write	write() Write data to Hive.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

write

public static HCatalogIO.Write write()

Write data to Hive.

read

public static HCatalogIO.Read read()

Read data from Hive.