The Data Processing component of BDD runs a set of processes and jobs. This set is called data processing workflows. Many of these processes run natively in Hadoop.
The Data Processing component controls several workflows in BDD. For example, you can create workflows for data loading, data updates, and others. The Data Processing component discovers new Hive tables and loads data into BDD. It runs data refresh operations and incremental updates. It also keeps BDD data sets in synch with Hive tables that BDD creates.
For example, during a data loading workflow, the Data Processing component performs these tasks:
- Discovery of data in Hive tables
- Creation of data sets in BDD
- Running a select set of enrichments on discovered data sets
- Profiling of the data sets
- Indexing of the data sets, by streaming data to the Dgraph.
To launch a data processing workflow when Big Data Discovery starts, you use the Data Processing Command Line Interface (DP CLI).
Data Processing CLI
The DP CLI is a shell Linux utility that launches data processing workflows in Hadoop. You can control their steps and behavior. You can run the DP CLI manually or from a cron job. You can run the data processing workflows on an individual Hive table, all tables within a Hive database, or all tables within Hive. This depends on DP CLI settings, such as a blacklist and a whitelist.
Here are some of the jobs you can run with DP CLI:
- Load data from Hive tables after installing Big Data Discovery (BDD). When you first install BDD, your existing Hive tables are not processed. You must use the DP CLI to launch a data processing operation on your tables.
- Run data updates. They include:
- An operation to refresh data. It reloads an existing data set in a Studio project, replacing the contents of the data set with the latest data from Hive in its entirety.
- An incremental update. It adds newer data to existing data sets in a Studio's project.
- Launch the BDD Hive Table Detector (this is a utility in Data Processing). The BDD Hive Table Detector detects if a new table is added to Hive. It then checks the whitelist and blacklist. If the table passes them, it creates a data set in BDD. It also deletes any BDD data set that does not have a corresponding source Hive table. This keeps BDD data sets in synch with data sets in Hive. For detailed information on how data sets are managed in BDD, see Data set lifecycle in Studio.
For information on Data Processing and the DP CLI, see the Data Processing Guide.