Undermoon is a self-managed Redis clustering system based on Redis Cluster Protocol supporting:
- Horizontal scalability and high availability
- Cluster management through HTTP API
- Automatic failover for both master and replica
- Fast scaling
Any storage system implementing redis protocol could also somehow work with undermoon, such as KeyDB.
For more in-depth explanation of Redis Cluster Protocol and how Undermoon implement it, please refer to Redis Cluster Protocol.
Metadata storage stores all the metadata of the whole undermoon cluster,
including existing Redis instances, proxies, and exposed Redis clusters.
Now it's an in-memory storage server called Memory Broker.
When using undermoon-operator,
this Memory Broker will change to use ConfigMap to store the data.
Coordinator will synchronize the metadata between broker and server proxy. It also actively checks the liveness of server proxy and initiates failover.
The storage cluster consists of server proxies and Redis instances. It serves just like the official Redis Cluster to the applications. A Redis Cluster Proxy could be added between it and applications so that applications don't need to upgrade their Redis clients to smart clients.
Chunk is the smallest building block of every single exposed Redis Cluster. Each chunk consists of 4 Redis instances and 2 server proxies evenly distributed in two different physical machines. So the node number of each Redis cluster will be the multiples of 4 with half masters and half replicas.
The design of chunk makes it very easy to build a cluster with a good topology for workload balancing.
Using undermoon-operator is the easiest way to create Redis clusters if you have Kubernetes.
helm install my-undermoon-operator undermoon-operator-<x.x.x>.tgz
helm install \
--set 'cluster.clusterName=my-cluster-name' \
--set 'cluster.chunkNumber=2' \
--set 'cluster.maxMemory=2048' \
--set 'cluster.port=5299' \
my-cluster \
-n my-namespace \
undermoon-cluster-<x.x.x>.tgz
See the README.md of undermoon-operator
for how to use it.
Or you can set them up without docker following this docs: setting up undermoon manually.
undermoon tries to avoid unsafe and some calls that could crash like unwrap.
Run the following commands before committing your codes:
$ make lint
$ make test
See more in the development guide.