Streams

Streams are flows of data in GDN that capture data in motion. Streams work using the publish-subscribe, aka pub-sub model where producers publish messages to streams and consumers subscribed to these streams consume and process these messages, and send an acknowledgement after processing.

producer/publisher --> stream --> subscription --> consumer

Start working with Streams

Start creating, publishing, and subscribing to streams.

Client SDKsCreate, subscribe and publish to streams using our Python and Javascript SDKs.REST APIsLeverage our extensive list of API endpoints to work with GDN Streams.Web ConsoleUse our intuitive user interface to send, receive and subscribe to streams.GDN CLIInstall and use the interactive GDN CLI to start subscribing and publishing to streams.

Why use streams?

Streams enable:

• Seamless geo-replication of messages across regions with persistent message storage.
• Very low publish and end-to-end latency with guaranteed message delivery.
• Seamless scalability to over a million topics
• Multiple subscription modes (exclusive, shared, and failover) for streams

Stream Names

As in other pub-sub systems, streams in GDN are named channels for transmitting messages from producers to consumers. Stream names are URLs with a well-defined structure:

persistent://tenant/fabric/stream-name

Stream name component	Description
persistent	This identifies the type of stream. GDN currently supports only persistent streams. With persistent streams, all messages are durably persisted on disk (that means on multiple disks).
tenant	The stream tenant within the instance. Tenants are essential to multi-tenancy in GDN
geofabric	The administrative unit of the stream, which acts as a grouping and geo-fencing mechanism for related streams. Stream configuration is performed at the fabric level. Each tenant can have multiple fabrics.
stream-name	The final part of the name. Stream names are freeform.

Streams and Fabrics

A fabric is a geo-fenced grouping within a tenant. A tenant can create and house multiple fabrics.

For example, a tenant with different applications can create a separate fabric for each application. A fabric allows the application to create and manage a hierarchy of streams. The stream my-tenant/app1 is a fabric for the application app1 for my-tenant. You can create any number of streams under the fabric.

note

Every collection within a fabric is also a stream with the same name.