Poor performance on ssd raid1 for 200M documents
Tue, 03/05/2013 - 03:36
Hello,
I'm trying to benchmark the couchbase on 4 nodes cluster with 4 ssd(120GB full capacity) raid 1, 32GB RAM per node on 200M (100 bytes 10 fields) documents in the cluster by YCSB(8 clients with 32 threads, 50 read/50 update).The RAM limit is 80%.
I get an excellent performance result for 50M documents - 600K ops/sec however on the same settings I got only ~30K ops/sec for 200M documents.
What kind of settings should I tune up to get a comparable throughput?
Thank you in advance.
Elena,
Performance will heavily depend on your working set. Are you just randomly accessing data across the 200 million document? Couchbase works best with the working set in memory, and that's what's recommended. the workload can be read, mixed or write, it doesn't matter.
Seems like with 200M documents, you will have a low resident ratio and a very high cache miss ratio (if you are doing random accesses). Can you check the stats on the UI and see what these look like?