Huge number of TCP segment retransmissions
I have encountered network issues (documents are printing multiple time by chance) while cups printing from a Digitalocean server (CentOS) to a external printer. Doing a network analysis with Wireshark I saw that by chance packages are retransmitted to the print server and so documents are printed 2 or 3 times.
I have a server at an other cloud provider and with that I don’t have that problems.
A netstat -s for the digital ocean server shows:
netstat -s | grep retr 650374 segments retransmited 1 times recovered from packet loss due to fast retransmit 1 timeouts after reno fast retransmit 44015 fast retransmits 5833 forward retransmits 4373 retransmits in slow start 1 classic Reno fast retransmits failed 1428 SACK retransmits failed
For the other cloud provider it shows
netstat -s | grep retr 8389033 segments retransmited 73 times recovered from packet loss due to fast retransmit 16 timeouts after reno fast retransmit 54023 fast retransmits 3285 forward retransmits 8724 retransmits in slow start 37 classic Reno fast retransmits failed 1732 SACK retransmits failed
The number of retransmissions on the digitalocean server is significant higher than on the other cloud server from a other cloud provider - although the other cloud server has much more load and much more network traffic.
Does anyone have an idea what could be the reason for that?
Thanks for any help.