Hello Chin, you can extract delta using pig script and save it in another CF in Cassandra. By using Pentaho kettle you can then load the data from the CF to RDBMS. Pentaho Kettle is open source project. All of the process you can automate through Azkaban or Ozzie. Kafka is also an alternatives as metioned above. Regards Shamim
14.12.2012, 07:20, "cko2...@gmail.com" <cko2...@gmail.com>: > We will use Cassandra as logging storage in one of our web application. The > application only insert rows into Cassandra but never update or delete any > rows. The CF is expected to grow by about 0.5 million rows per day. > > We need to transfer the data in Cassandra to another relational database > daily. Due to the large size of the CF, instead of truncating the relational > table and reloading all rows into it each time, we plan to run a job to > select the "delta" rows since the last run and insert them into the > relational database. > > We know we can use Java, Pig or Hive to extract the delta rows to a flat file > and load the data into the target relational table. We are particularly > interested in a process that can extract delta rows without scanning the > entire CF. > > Has anyone used any other ETL tools to do this kind of delta extraction from > Cassandra? We appreciate any comments and experience. > > Thanks, > Chin
