High latency on domain with CDN
I have problems with latency on my server, these are the tests I made with blitz.io
Latency album
https://i.stack.imgur.com/nKV1r.jpg
I would uploaded images here but it requires 10+ rep, and can't post multiple links so I uploaded pictures in album on imgur.
My domain is hosted with Cloudflare CDN. I am hosting on Cloud SSD based hosting, DigitalOcean.
Latency on server was ~40ms when there was no traffic.
Latency on server with CDN is now ~270ms
Latency on server with no CDN is ~300ms
I was previously hosting on Windows Azure,
Latency with no traffic was ~70ms
Latency with traffic was ~210ms
Still even though latency is higher on DigitalOcean my content is loading much faster then on Windows Azure servers.
Old Azure server, album
imgur.com/a/fpHK9
I can't post more then 2 links, c/p in browser
No firewall configured on DigitalOcean Server, was default Azure FW on Microsoft Azure servers, configuration with endpoints.
Content
Payload size
images ~156 KB
CSS ~12 KB
logo ~20 KB
random content loaded on each pageviews 4KB
total random content size 116 KB thats gets loaded
total ~300KB, all hosted over CDN. Not all get loaded at once.
Cloudflare stats, album
imgur.com/a/qxnbo
I can't post more then 2 links, c/p in browser
Network analyze with Firefox, album
https://i.stack.imgur.com/8z16E.jpg
Content is loaded after page has finished loading.
Memory
Server is running on lighttpd.
Memory
XXX@XXX:~# free -h
total used free shared buffers cached
Mem: 995M 835M 159M 0B 150M 471M
-/+ buffers/cache: 214M 780M
Swap: 1.0G 26M 997M
Top
top - 14:29:13 up 21 days, 1:00, 1 user, load average: 0.00, 0.04, 0.05
Tasks: 95 total, 1 running, 94 sleeping, 0 stopped, 0 zombie
%Cpu(s): 3.0 us, 1.4 sy, 0.0 ni, 94.3 id, 0.7 wa, 0.0 hi, 0.7 si, 0.0 st
KiB Mem: 1019056 total, 856144 used, 162912 free, 153748 buffers
KiB Swap: 1048572 total, 27084 used, 1021488 free, 482660 cached
Droplet is on 1Gbit shared connection.
Connections
When issuing netstat -n I count ~620 TIME_WAIT/ESTABLISHED connections
When issuing netstat -n | grep 'ESTABLISHED' I count ~120 connections
100MB test
100MB download test
XXX@XXX:~# wget speedtest.london.linode.com/100MB-london.bin
--2013-09-05 14:35:08-- speedtest.london.linode.com/100MB-london.bin
Resolving speedtest.london.linode.com (speedtest.london.linode.com)... 176.58.107.39, 2a01:7e00::4b
Connecting to speedtest.london.linode.com (speedtest.london.linode.com)|176.58.107.39|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: ‘100MB-london.bin’
100%[===================================================================================================>] 104,857,600 8.46MB/s in 11s
2013-09-05 14:35:19 (9.47 MB/s) - ‘100MB-london.bin’ saved [104857600/104857600]
100MB upload test
I created another server and just downloaded from first one same 100MB file
XXX@XXX:~# wget domain_with_no_cdn.com/test/100MB-london.bin
--2013-09-05 12:38:00-- domain_with_no_cdn.com/test/100MB-london.bin
Resolving domain_with_no_cdn.com (domain_with_no_cdn.com)... Server_IP
Connecting to domain_with_no_cdn.com (domain_with_no_cdn.com)|Server_IP|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: `100MB-london.bin'
100%[=======================================================================================>] 104,857,600 13.4M/s in 6.1s
2013-09-05 12:38:07 (16.5 MB/s) - `100MB-london.bin' saved [104857600/104857600]
100MB upload test over CDN
XXX@XXX:~# wget domain_over_CDN.com/test/100MB-london.bin
--2013-09-05 12:44:26-- domain_over_CDN.com/test/100MB-london.bin
Resolving domain_over_CDN.com (domain_over_CDN.com)... 108.162.200.169, 141.101.127.168
Connecting to domain_over_CDN.com (domain_over_CDN.com)|108.162.200.169|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: `100MB-london.bin'
100%[=======================================================================================>] 104,857,600 12.5M/s in 11s
2013-09-05 12:44:37 (8.96 MB/s) - `100MB-london.bin' saved [104857600/104857600]
Can you tell me what are the possible issues with my setup?
Can you give me some tutorials or links where I can learn how to balance load between servers or what exactly do I need to do to get latency under 100ms.
Day 2, testing
I contacted Cloudflare support and they resolved issue in my country, but not all servers are reporting latency below 100ms.
I posted new pictures in album
imgur.com/a/xajge
I can't post more then 2 links, c/p in browser
As you can see from picture 2, there are still issues with servers in US on domains with CDN. I suppose they are experience problems cause of updates on hardware last few weeks but I would like to know how to lower the latency on my own server bellow 100ms.
I am dividing pixel ping server and data server so hopefully that will lower some of latency down.
If someone has any guidance which can resolve my issues, please any help is appreciated :)
