Why is terminal access to my Linode so slow?
Editing locally on 2.7 GHz MacBook Pro with 16 GB SSD RAM and SSD hard drive. CPU, RAM, and hard drive utilization very low.
Running iTerm 3 and Tmux 2.3 locally and whatever version of SSH that comes pre-installed with MacOS 10.12.5 (not sure how to find version info)
Network bandwidth up/down: 5 Mbps/60 Mbps
I've checked status.linode.com and all systems were operational
I'm using Vim 7.4 on my server
My Linode disk utilization is 12%
There should be disk I/O bottle necks as I'm the only one on the server and all I'm doing is editing.
Memory utilization appears to be OK. Here's output from "free -m":
total used free shared buffers cached
Mem: 988 675 313 62 98 350
-/+ buffers/cache: 226 762
Swap: 1023 11 1012
Here's ping output:
PING web01.example.com (173.255.211.117): 56 data bytes
64 bytes from 173.255.211.117: icmp_seq=0 ttl=52 time=22.186 ms
64 bytes from 173.255.211.117: icmp_seq=1 ttl=52 time=23.392 ms
64 bytes from 173.255.211.117: icmp_seq=2 ttl=52 time=22.192 ms
64 bytes from 173.255.211.117: icmp_seq=3 ttl=52 time=22.641 ms
64 bytes from 173.255.211.117: icmp_seq=4 ttl=52 time=24.805 ms
64 bytes from 173.255.211.117: icmp_seq=5 ttl=52 time=681.515 ms
64 bytes from 173.255.211.117: icmp_seq=6 ttl=52 time=868.982 ms
Request timeout for icmp_seq 7
64 bytes from 173.255.211.117: icmp_seq=7 ttl=52 time=1342.053 ms
64 bytes from 173.255.211.117: icmp_seq=8 ttl=52 time=594.793 ms
64 bytes from 173.255.211.117: icmp_seq=9 ttl=52 time=22.763 ms
--- web01.example.com ping statistics ---
10 packets transmitted, 10 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 22.186/362.532/1342.053/454.242 ms
Here is traceroute output. There appears to be failed jumps as I approach the Linode network:
1 192.168.0.1 (192.168.0.1) 2.057 ms 0.975 ms 0.971 ms
2 142.254.236.169 (142.254.236.169) 8.515 ms 9.007 ms 8.365 ms
3 agg61.lsaicaev01h.socal.rr.com (24.30.168.17) 9.540 ms 9.163 ms 8.799 ms
4 agg11.lsaicaev01r.socal.rr.com (72.129.18.192) 10.083 ms 10.758 ms 12.809 ms
5 agg26.lsancarc01r.socal.rr.com (72.129.17.0) 11.547 ms 39.135 ms 16.272 ms
6 bu-ether26.lsancarc0yw-bcr00.tbone.rr.com (66.109.3.230) 16.723 ms 15.309 ms 15.926 ms
7 ae2.lsancarc0yw-bpr01.tbone.rr.com (66.109.1.41) 11.215 ms 40.996 ms 10.192 ms
8 10ge5-6.core1.lax2.he.net (64.62.153.205) 10.811 ms 14.077 ms 10.399 ms
9 100ge8-2.core1.pao1.he.net (184.105.81.237) 26.555 ms 23.554 ms 25.015 ms
10 10ge8-8.core3.fmt2.he.net (184.105.222.89) 44.632 ms 26.923 ms 79.891 ms
11 * * *
12 173.230.159.17 (173.230.159.17) 22.341 ms 23.371 ms 22.515 ms
13 li221-117.members.linode.com (173.255.211.117) 22.939 ms 24.026 ms 21.829 ms
This seems to have become a problem in the last week or so. Thanks for your help!
8 Replies
Your ping shows some packets returning late, which means during that particular timeframe, your ssh session surely would have lagged.
Try to run a ping to your Linode, while also running a ping elsewhere in the world, to see if the slow ping is happening just to linode, or everywhere.
Here is output of mtr from my laptop to my server:
Start: 2017-07-12T12:46:56-0700
HOST: Roberts-MacBook-Pro.local Loss% Snt Last Avg Best Wrst StDev
1.|-- 192.168.0.1 0.0% 10 1.1 70.3 1.0 371.7 126.0
2.|-- 142.254.236.169 0.0% 10 8.7 249.3 8.4 1029\. 397.6
3.|-- agg61.lsaicaev01h.socal.rr.com 0.0% 10 9.0 354.1 9.0 1031\. 458.5
4.|-- agg11.lsaicaev01r.socal.rr.com 0.0% 10 10.0 390.8 9.6 1171\. 496.1
5.|-- agg26.lsancarc01r.socal.rr.com 0.0% 10 15.2 360.4 12.1 1090\. 455.1
6.|-- bu-ether26.lsancarc0yw-bcr00.tbone.rr.com 0.0% 10 11.4 401.9 10.6 1444\. 538.0
7.|-- 0.ae1.pr1.lax00.tbone.rr.com 0.0% 10 10.0 369.1 9.9 1364\. 501.6
8.|-- 10ge5-6.core1.lax2.he.net 0.0% 10 10.8 339.6 10.6 1286\. 463.4
9.|-- 100ge8-2.core1.pao1.he.net 0.0% 10 36.0 314.7 18.5 1206\. 421.2
10.|-- 10ge8-8.core3.fmt2.he.net 0.0% 10 29.8 337.5 18.3 1124\. 450.8
11.|-- ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
12.|-- 173.230.159.1 0.0% 10 22.0 347.4 21.4 1268\. 493.5
13.|-- li221-117.members.linode.com 0.0% 10 22.1 316.8 21.8 1187\. 458.1
Here is mtr from the server to my laptop:
Start: Wed Jul 12 20:04:45 2017
HOST: web01 Loss% Snt Last Avg Best Wrst StDev
1.|-- 23.92.24.3 0.0% 10 1.0 0.7 0.6 1.0 0.0
2.|-- 173.230.159.16 0.0% 10 0.8 0.8 0.7 0.9 0.0
3.|-- sjo-b21-link.telia.net 0.0% 10 1.3 1.5 1.3 2.5 0.0
4.|-- palo-b22-link.telia.net 0.0% 10 1.7 1.7 1.6 2.3 0.0
5.|-- las-b22-link.telia.net 0.0% 10 11.4 11.4 11.3 11.6 0.0
6.|-- chartercommunications-ic-325646-las-b22.c.telia.net 0.0% 10 12.5 17.4 12.2 57.3 14.1
7.|-- unk-426d057a.adelphiacom.net 0.0% 10 14.9 15.6 12.6 18.9 2.1
8.|-- agg2.lsancarc01r.socal.rr.com 0.0% 10 13.1 15.2 12.5 18.9 2.3
9.|-- agg1.lsaicaev01r.socal.rr.com 0.0% 10 15.6 16.2 15.0 17.8 0.9
10.|-- agg1.lsaicaev01h.socal.rr.com 0.0% 10 15.0 15.0 14.8 15.1 0.0
11.|-- agg1.lsaicaev03m.socal.rr.com 0.0% 10 14.0 14.2 13.9 15.4 0.3
12.|-- cpe-104-172-228-26.socal.res.rr.com 0.0% 10 22.0 21.5 21.1 22.7 0.3
The issue appears to be with the route from my laptop to my linode but I don't know what actions I can take to remediate or resolve this problem.
The outbound report suggests that it could be one of a few things. The first, most annoying possibility, is that your Mac is triggering scanning frequently (usually due to poor signal, common in apartment complexes where there's a lot of interference with other residents' wifi, but there's also times where OS X will do it unnecessarily). The second possibility is some other problem with your wifi or home router. The third possibility is a problem with your ISP's network, possibly congestion related.
One thing you can do is run mtr without the –report and --report-wide flags, and switch to the graph with latency display (press 'd' twice, on recent mtr you can add '--displaymode 2' to the command line), and then look at the graph when the lag hits. Grabbing a screenshot (Cmd+Shift+4, then click and drag over the mtr, or follow that up with space and then click the terminal window) and posting a link to it here (upload it to imgur or something) will let us see exactly what it's like when it happens, and we can probably figure out which one it is easier from that.
Here are two screen shots:
Thank you for your help! I'm learning from you.
Start: 2017-07-12T16:03:52-0700
HOST: Roberts-MacBook-Pro.local Loss% Snt Last Avg Best Wrst StDev
1.|-- 192.168.0.1 0.0% 10 0.5 0.5 0.4 0.5 0.1
2.|-- 142.254.236.169 0.0% 10 7.9 8.2 7.9 8.9 0.3
3.|-- agg61.lsaicaev01h.socal.rr.com 0.0% 10 9.0 8.8 8.0 10.1 0.6
4.|-- agg11.lsaicaev01r.socal.rr.com 0.0% 10 8.4 12.7 8.4 17.5 2.8
5.|-- agg26.lsancarc01r.socal.rr.com 0.0% 10 13.5 15.1 11.2 17.4 2.0
6.|-- bu-ether26.lsancarc0yw-bcr00.tbone.rr.com 0.0% 10 12.5 15.2 11.3 20.3 3.0
7.|-- 0.ae1.pr1.lax00.tbone.rr.com 0.0% 10 10.1 10.7 9.3 18.1 2.6
8.|-- 10ge5-6.core1.lax2.he.net 0.0% 10 18.5 12.8 9.5 18.5 3.6
9.|-- 100ge8-2.core1.pao1.he.net 20.0% 10 17.9 20.0 17.7 25.6 2.7
10.|-- 10ge8-8.core3.fmt2.he.net 0.0% 10 18.7 19.6 17.8 24.8 2.2
11.|-- ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
12.|-- 173.230.159.1 0.0% 10 27.3 22.0 20.5 27.3 1.9
13.|-- li221-117.members.linode.com 0.0% 10 21.6 21.8 21.4 22.2 0.3
@dwfreed:
Yeah, that looks like the second one. Try connecting to your router over a wired connection, to determine if it's something to do with wifi, or the device itself.
Could you tell me precisely what it was about the second image that led you to believe that it was my wifi or device?
Thank you very much. If you were here, I'd buy you a beer.