Yesterday, Google went public with the first beta of Cloud Pub/Sub – catching up with both the mighty Amazon Web Services and Microsoft, who respectively offer Simple Queue Service and Azure Service Bus. Similar to JMS, this backend messaging service designed to provide reliable, many-to-many, asynchronous messaging between various applications. The system was originally announced at the Chocolate Factory’s I/O developer conference in 2014, but it’s been private Alpha up until now.
With Cloud Pub/Sub, you can send messages from publisher applications to a “topic” and other applications can subscribe to receive the messages. According to the Google Cloud Platform blog, this means by decoupling senders and receivers, the service lets developers communicate between independently written applications. You can create up to 10k of these topics , and send up to 10k messages per second. If you’re curious to see it in action, you can check out this road test on Github, which might have been one of the most interesting things going on during this year’s Oscars.
Bear in mind that this is just a Beta release, so for now, your applications can only communicate if their Cloud projects have the same owner. Additionally, push messages are only deliverable to HTTPS endpoints. To receive messages in subscriber applications, you’ll need a web service component (for example Google App Engine app) or a web server hosted on an external location or Google Compute Engine.
In terms of security, Cloud Pub/Sub also lacks any specific access control mechanisms, with access controls using the roles defined for Cloud projects. This means that project Owners and Editors can perform operations on topics and subscriptions, and Viewers are restricted to Get and List operations on topics and subscriptions. You can expect more fine-grained role-based access control scheme for manipulating topics and subscriptions in the future.
For now, you can play with this service for free, but once the Beta phase is over, it’ll be $0.40 per million for the first 100 million API calls each month, and $0.25 per million for the next 2.4 billion operations thereafter, and $0.05 per million for anything above that. With this Beta release and public announcement of the pricing structure, Tech Crunch speculate that we can expect to see the final version launched at this summer’s I/O event.