Detail
An Aerospike cluster cannot contain more than 256 nodes; trying to add additional nodes will result in a message similar to
ignoring node: bb9040011ac4202 - exceeding maximum supported cluster size 256
Answer
There are several reasons why the cluster size is limited to 256 and further expansion is not on the roadmap:
- The principal still handles a lot of cluster communications putting too much weight on one node
- The intra-node metadata for 256 nodes fits in 1 byte; moving to 512 would double that.
- Increased likelihood of some node in the cluster having an issue at any given time (in our experience, the sweet spot for truly stable clusters is actually under 100)
- With 256 nodes each node holds 16 partitions, with 512 it would be 8 so the uniform balance algorithm would have trouble
For use cases where 256 nodes are not enough capacity, we recommend distributing traffic across multiple clusters which use XDR to keep the data in sync.
Notes
Prior to Aerospike Server 5.0, the limit was 128 nodes per cluster.
Applies To Earliest Version
5.0
Applies To Latest Version
Current Version
