Round-Robin Databases
Round-robin database (RRD) is a very special type of storage designed to keep the aggregated time series statistics in a file or memory-mapped ring buffers.
Since data is stored in a circular buffer-based database, the system storage footprint remains constant over time.
AggreGate platform features an integrated RRD storage facility that interoperates with the statistical process control module. The module collects value updates and events, extracts floating-point numbers from them and pushes those numbers to the RRD.
Although RRD is very limited in its capabilities, it has a number of unique advantages:
- Extremely fast insert rate (more than a million samples per second on a single machine)
- Extremely fast access to pre-aggregated long-term statistics (monthly averages for ten thousand devices and ten years will load in under one second)
- Constant disk footprint of the whole database
