PubNub operates 15 points-of-presence (PoPs) with several layers of redundancy at each PoP. The PubNub DSN spans multiple cloud providers, with PoPs deployed across Western and Eastern Europe, North and South America, and throughout Asia.
Security policies are enforced at the edge, where we offer a programmable authorization layer called PubNub Access Manager. Access Manager offers the ability to grant & revoke access permissions on-demand across every PoP, enabling developers to quickly and easily implement authorization rules in realtime.
The core of the PubNub Data Stream Network is written in C for performance, handling all data replication across PoPs as well as reliability logic for devices connected to the PubNub DSN. PubNub’s data propagation strategy follows a multi-master, high availability model with very high redundancy; every message published into the PubNub DSN by default is replicated to all PoPs, making the messages available to any subscribing device in the world, regardless of geographical location, with the fastest response time possible. When dictated by the customer, geographically-restricted data replication rules are easily configured to ensure that legislatively restrictive data (for example, PII data) can be retained in a single geography, meeting regional legislative requirements such as the EU-US Privacy Shield.
If a device is unable to connect to the closest data center, it will gracefully connect to the next closest data center and automatically catch-up on messages that haven’t been delivered, via a “Store and Forward” model. In addition, if communications are interrupted mid-session (e.g. device loses internet), the same “Store and Forward” model is used to instantly catch-up on missed data as the device reconnects.
PubNub’s core Data Stream Network is extremely fast; routing a message through the PubNub network takes as little as 4-9 milliseconds of latency, often resulting in an end-to-end experience of 30-40ms for users on a broadband connection.
The network scales to handle any customer’s rapid, unforeseen growth or unexpected usage spikes. PubNub has helped small apps grow into worldwide hits, and all along the way we have been there to keep the experience consistent – we know customers can go from having thousands of users one day, to millions of users the next day.
Currently the network services over 1.8 trillion messages per month across 330 million unique devices worldwide for over 2,000 customers – all in under 1/4 second, while guaranteeing our customers a 99.999% uptime.