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Pravega organizes data into Streams. According to the Pravega site, a Stream is a durable, elastic, append-only, unbounded sequence of bytes. Pravega streams are based on an append-only log-data structure. By using append-only logs, Pravega rapidly ingests data into durable storage.
When a user creates a Stream in Pravega, the user gives the Stream a name such as JSONStreamSensorData to indicate the types of data it stores. Pravega organizes Streams into Scopes. A Pravega Scope provides a secure namespace for a collection of streams and can contain multiple Streams. Each Stream name must be unique within the same Scope, but there can be identical Stream names within different Scopes.
A Stream is uniquely identified by its name and the scope it belongs to. Clients can append data to a Stream (writers) and read data from the same Stream (readers).
Within the Streaming Data Platform, a Scope is created in the UI by creating an analytics project. A Pravega Scope is automatically created once the analytics project is created. The name of the Pravega Scope is automatically inherited from the analytics project name, so choose the name carefully. Both names are identical.
Before SDP 1.2, each analytics project was associated with a single Pravega Scope, which means that each project was completely isolated from others. Since SDP 1.2, it is possible to allow members of a project to be able to read Pravega Streams from a different project. This helps data scientists who want to share Streams between multiple projects without having to duplicate the data. This feature is called Cross Project Pravega Scope Sharing.