This is a simple story how we migrated a live production cluster with all its data into a new cluster, all without downtime. Old cluster: 60 c4.4xlarge instances Cassandra 2.1.12, 256 vnodes per host Each instance had two 1500 GB GP2 EBS disks. This matches the c4.4xlarge EBS bandwidth quite well as max bandwidth for …
The NoSQL versus RDBMS war started a few years ago and as the new technologies are starting to get more mature it seems that the two different camps will be moving towards each other. [read more…]
We have built a facebook style “messenger” into our web site which uses cassandra as storage backend. I’m describing the data schema to server as a simple example how cassandra (and nosql in general) can be used in practice…
It’s known that in Cassandra the compaction hurts the node performance so that the node might miss some requests. That’s why it’s important to handle these situations and the client needs to retry the operation into another working host. We have been storing performance data from each cassandra request which we do into our five …