Accessing data in Cassandra
Originally developed by Facebook to handle its massive data requirements, before being open-sourced to the Apache Foundation, Apache Cassandra is an open source, distributed, NoSQL database system. These data sources are an alternative to the more traditional relational database management systems. The Cassandra system offers scalability, performance, tunability, and reliability on commodity hardware or in a cloud infrastructure. Cassandra also supports replicating data across multiple data centers for improved performance for end users and higher availability of very large amounts of data. Cassandra distributes data across all nodes in the same way, without a master node or named node, and Cassandra supports read/write anywhere in the cluster.
Cassandra uses a row-oriented column schema, similar to Google BigTable. Within that schema are:
Keyspaces, which are comparable to databases in RDBMS
Column families, which are comparable to RDBMS tables, although they offer more flexibility
Rows and columns in column families, which can be indexed by key values
To access Cassandra data using BIRT Designer, you must develop JavaScript code to call the Cassandra Hector API to retrieve data. More information about this requirement is available at the following URL:
As with other types of data sources, for a report to use data from an Apache Cassandra database, you must create the following BIRT objects:
A data source that contains the information to connect to a Cassandra database
A data set that specifies the data to retrieve