Retrieving missed in cache keys performance
I'm evaluating Couchbase right now and I'm not very satisfied with the getBulk performance results for values stored in Hard Drive.
The tests are performed on the machine with 10 Gb Ram.
I'm trying to increase the speed of retrieving 1200 keys from 60 Gb bucket stored mostly in Hard Drive.
Retrieving keys which are missed in cache decreasing from 300-400 down to 30-40 keys per second with increasing size of bucket. one value is approximately 6000 bytes.
Am I correct that performance of retrieving for missed in cache keys should not decrease significantly with increasing of total keys number in bucket?
What could you suggest to increase speed of fetching data from HDD/SSD?
Yes if you are seeing xx% of your calls for documents are coming from HD. Those calls will have delays no matter how big your cluster is.
If you are having concerns with cache misses and delay from HD. I would recommend you increase your working set of memory.
Go to this link it talks more about it. www.couchbase.com/docs/couchbase-manual-2.0/couchbase-bestpractice-sizin...
Here is a link that goes into how the working set works www.couchbase.com/docs/couchbase-manual-2.0/couchbase-introduction-archi...