I have set up two Mongo instances in EC2 having RAID10. I set up replica set using those two servers and found that this replica is very very slow over network. If I log in locally and issue query inside mongo console all is fine. I tested disk speed no issue here:
sudo dd if=/dev/zero of=/data/output2.img bs=8k count=100k 102400+0 records in 102400+0 records out 838860800 bytes (839 MB) copied, 1.87101 s, 448 MB/s
And similar set up that is without replication works fast. How can I track down this issue ?