Re:How We Knew It Was Time to Leave the Cloud
by kijiki on Sunday November 13, 2016 @08:26AM
(#12943194)
If you're rolling your own, you can tune these things.
For example, in this case, since they're IOPs-bound first, and probably network-bound second, you can cram 16 SSDs in a box, and then put a dual-port 25Gig Ethernet NIC up to 2 leaf switches at the top of rack, and then build a CLOS out of 100G spine switches, so that there are essentially never any network bottlenecks for Ceph.
This is very similar to DreamHost's DreamCompute cluster design, though they're using 2x 10G to the servers, and 40G up to the spines, since 25G/100G wasn't available when they built the cluster.
For example, in this case, since they're IOPs-bound first, and probably network-bound second, you can cram 16 SSDs in a box, and then put a dual-port 25Gig Ethernet NIC up to 2 leaf switches at the top of rack, and then build a CLOS out of 100G spine switches, so that there are essentially never any network bottlenecks for Ceph.
This is very similar to DreamHost's DreamCompute cluster design, though they're using 2x 10G to the servers, and 40G up to the spines, since 25G/100G wasn't available when they built the cluster.