Active-Semiactive Media Stack

No media loss, but sync can spread malware

Executive Summary

The active–semi-active model uses a clone recorder that ingests media directly from cameras in parallel with the primary, but stays detached from client services until failover. This design improves consistency, since both nodes hold current media and no storage is lost when the primary fails. Failover occurs quickly as the standby attaches to the application framework, though it does not allow stream-level recovery—only complete stack takeover. The approach introduces a cybersecurity risk: synchronization of missing media and configuration data between recorders, if used, can serve as a pathway for malware or corruption to spread. Efficiency remains one-to-one, requiring a dedicated standby for each protected recorder, which limits scalability.

Active-Semiactive Media Stack

Failover

Only one stack can register with the other parts of the application framework to offer services. Usually, this is the primary. When the primary stack fails, the second stack 'attaches' quickly to provide services. But the solution does not offer stream-level failover.

Clone Active when Primary fails

Consistency

Both stacks, when functional, record directly from the source, ensuring no media storage loss in the event of failure episodes. Synchronization of missing media and configuration updates is continuously performed across stacks to maintain consistency. Alternatively one may choose to use edge restoration.

No Media Gaps during Failover

Cybersecurity

Copying missing media content and stack config between recorders, if used, risks spreading malware and other cyber threats.

Malware propogates through the sync channel

Efficiency

Efficiency is 1:1, meaning one standby node can support one primary node failure. Two standbys are required to support two simultaneous primary node failures, and so on.