Forming a cluster of embedded Cassandra instances

Hi all, TL;DR: I have a very superficial understanding of Cassandra and am currently evaluating it for a project. * Can Cassandra be embedded into another JVM application? * Can such embedded instances form a cluster? * Can the application use the the failure detection and cluster membership

Re: Cassandra eats all cpu cores, high load average

> Wide rows? How wide? How many rows per partition, typically and at the > extreme? how many clustering columns? Yes, wide rows with deletions of old data. Number of keys (estimate): 909428 How I can calculate rows per partition via nodetool/jmx? ~ From 100 to 5,000,000. I know its

Re: Sudden disk usage

Hi, what kind of compaction strategy do you use? What you are about to see is a compaction likely - think of 4 sstables of 50gb each, compacting those can take up 200g while rewriting the new sstable. After that the old ones are deleted and space will be freed again. If using

Re: Forming a cluster of embedded Cassandra instances

HA requires an odd number of replicas - 3, 5, 7 - so that split-brain can be avoided. Two nodes would not support HA. You need to be able to reach a quorum, which is defined as n/2+1 where n is the number of replicas. IOW, you cannot update the data if a quorum cannot be reached. The data on any

Re: Forming a cluster of embedded Cassandra instances

+1 to what jack said. Don't mess with embedded till you understand the basics of the db. You're not making your system any less complex, I'd say you're most likely going to shoot yourself in the foot. On Sat, Feb 13, 2016 at 2:22 PM Jack Krupansky wrote: > HA requires

Re: Sudden disk usage

We use SizeTieredCompaction. The nodes were about 67% full and we were planning on adding new nodes (doubling the cluster to 6) soon. I've been watching the disk space used, and the nodes were taking about 100GB during compaction, so I thought we were going to be okay for another week. The