Pravega connection

The Pravega connection represents and contains all of the information that is needed to connect and log into Pravega.

Connection options

• URI - (Required) The URI endpoint of the Pravega controller in the form tcp://host:port or tls://host:port
• Scope - (Required) The Pravega scope containing the data stream.
• Stream Name - (Required) The name of the data stream to read or write.
• Create Scope - When selected, the Pravega scope will be automatically created. Only select this if Pravega is running in stand-alone mode.
• Pravega Authentication Required - Indicates whether authentication is required for Pravega.
• Pravega Username - Used when Pravega authentication is required.
• Pravega Password - Used when Pravega authentication is required.

Pravega connection glossary of terms

The glossary of terms related to Pravega is:

• Stream: Pravega organizes data into Streams. A Stream is a durable, elastic, append-only, unbounded sequence of bytes having good performance and strong consistency. A Pravega Stream is similar to but more flexible than a "topic" in popular message oriented middleware such as RabbitMQ or Apache Kafka.

  A Stream is unbounded in size – Pravega itself does not impose any limits on how many Events (i.e., bytes) are stored in a Stream. Pravega’s design horizontally scales from a few machines to an entire datacenter’s capacity.

• Events: Pravega's client API allows applications to write and read data to/from Pravega in the form of Events. An Event is represented as a set of bytes within a Stream. For example, an Event could be as simple as a small number of bytes containing a temperature reading from an IoT sensor composed of a timestamp, a metric identifier, and a value.

• Routing Key: A Routing Key is a string used by developers to group similar Events. A Routing Key is often derived from data naturally occurring in the Event, like "customer-id" or "machine-id" or a declared/user-defined string. For example, a Routing Key could be a date (to group Events together by time) or it could be a IoT sensor id (to group Events by machine). A Routing Key is important in defining the read and write semantics that Pravega guarantees.

• Pravega Writer: An application that creates Events and writes them into a Stream. All data is written by appending to the tail (front) of a Stream.

• Pravega Reader: An application that reads Events from one or more Stream. See Working with Pravega Basic Reader and Writer for more information.

• Pravega Modes: There are two modes for running Pravega.

  • Standalone - Standalone mode is suitable for development and testing Pravega applications. It can either be run from the source code, from the distribution package, or as a docker container.
  • Distributed - Distributed mode runs each component separately on a single or multiple nodes. This is suitable for production in addition for development and testing. The deployment options in this mode include a manual installation, running in a docker swarm, or DC/OS.

Pravega security configuration

For information on how to configure Pravega for secure connections, visit Pravega Security Configuration.