Replicating data into Hadoop is achieved by generating character-separated values from ROW-based information that is applied directly to the Hadoop HDFS using a batch loading process. Files are written directly to the HDFS using the Hadoop client libraries. A separate process is then used to merge existing data, and the changed information extracted from the master database.
Deployment of the Hadoop replication is similar to other heterogeneous installations; two separate installations are created:
Service Alpha on the master extracts the information from the MySQL binary log into THL.
Service Alpha on the slave reads the information from the remote replicator as THL, applying it to Hadoop. The applier works in two stages:
Basic requirements for replication into Hadoop:
Hadoop Replication is supported on the following Hadoop distributions and releases:
Cloudera Enterprise 4.4, Cloudera Enterprise 5.0 (Certified) up to Cloudera Enterprise 5.8
HortonWorks DataPlatform 2.0
Amazon Elastic MapReduce
IBM InfoSphere BigInsights 2.1 and 3.0
MapR 3.0, 3.1, and 5.x
Pivotal HD 2.0
Apache Hadoop 2.1.0, 2.2.0
Source tables must have primary keys. Without a primary key, Tungsten Replicator is unable to determine the row to be updated when the data reaches Hadoop.