The 503 error

  • sever name: 1.terarows.com

  • time: 2022-02-21 16:05 UTC+08

  • server log: (none)

  • traceroute:

traceroute to 1.terarows.com (172.67.130.252), 30 hops max, 60 byte packets
 1  ZyXEL.Home (192.168.1.1)  0.424 ms  0.552 ms  0.717 ms503 error
 2  h254.s98.ts.hinet.net (168.95.98.254)  7.362 ms  7.537 ms  7.937 ms
 3  tpe4-3301.hinet.net (168.95.22.98)  8.249 ms  8.395 ms  9.241 ms
 4  tyfo-3031.hinet.net (220.128.8.242)  10.483 ms  10.479 ms  11.165 ms
 5  tyfo-4011.hinet.net (220.128.8.49)  10.590 ms tyfo-4011.hinet.net (220.128.8.69)  11.151 ms  11.261 ms
 6  r31-la.us.hinet.net (202.39.91.5)  146.794 ms  143.987 ms  143.964 ms
 7  r32-la.us.hinet.net (202.39.84.86)  141.479 ms  141.237 ms  140.469 ms
 8  141.101.72.250 (141.101.72.250)  162.206 ms  162.202 ms  162.261 ms
 9  141.101.72.32 (141.101.72.32)  136.882 ms 172.70.208.2 (172.70.208.2)  142.824 ms 172.70.212.2 (172.70.212.2)  136.166 ms
10  1.terarows.com (172.67.130.252)  140.547 ms  140.538 ms  141.476 ms
fl=464f66
h=1.terarows.com
ip=2001:b011:2012:37eb:eea8:6bff:fe2a:120
ts=1645429633.644
visit_scheme=https
uag=Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36 OPR/76.0.4017.123
colo=SJC
http=http/3
loc=TW
tls=TLSv1.3
sni=plaintext
warp=off
gateway=off

remarks:

  • Both web sites 1.terarows.com (which heavily utilizes AJAX technique) and www.terarows.com (which utilizes only a few AJAX technique) are hosted on the same hardware server.

  • The 503 error has been happening to 1.terarows.com from time to time for at least 2 years, but not always.

  • The 503 error seems to have been happening from only AJAX calls, but not from HTML elements.

  • The 503 error automatically disappeared without my intervention several seconds (or minutes, or hours) later.

  • At the moment when 503 error occurred to 1.terarows.com, www.terarows.com had been responding normally.

EDIT to add below:

traceroute to www.terarows.com (104.21.3.175), 30 hops max, 60 byte packets
 1  ZyXEL.Home (192.168.1.1)  0.529 ms  0.792 ms  1.060 ms
 2  h254.s98.ts.hinet.net (168.95.98.254)  7.933 ms  7.927 ms  8.483 ms
 3  tpe4-3301.hinet.net (168.95.22.98)  8.693 ms  8.688 ms  9.008 ms
 4  tyfo-3031.hinet.net (220.128.8.242)  10.738 ms  11.744 ms  11.839 ms
 5  tyfo-4011.hinet.net (220.128.8.69)  11.728 ms tyfo-4011.hinet.net (220.128.8.49)  11.830 ms tyfo-4011.hinet.net (220.128.8.73)  11.946 ms
 6  r31-la.us.hinet.net (202.39.91.5)  143.317 ms  143.400 ms  143.375 ms
 7  r32-la.us.hinet.net (202.39.84.86)  142.647 ms  140.018 ms  145.972 ms
 8  141.101.72.250 (141.101.72.250)  141.337 ms  141.905 ms  141.900 ms
 9  172.70.212.2 (172.70.212.2)  136.864 ms 172.70.208.2 (172.70.208.2)  144.605 ms 172.70.204.2 (172.70.204.2)  140.989 ms
10  www.terarows.com (104.21.3.175)  140.480 ms  141.471 ms  141.467 ms

EDIT 2: add HTTP server log

172.68.6.95 1.terarows.com - [21/Feb/2022:16:56:37 +0800] "POST /fastcgi/json HTTP/2.0" 503 252 "https://1.terarows.com/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.99 Safari/537.36"
172.68.6.135 1.terarows.com - [21/Feb/2022:16:56:40 +0800] "PRI * HTTP/2.0" 100 138976 "-" "-"
172.68.6.95 1.terarows.com - [21/Feb/2022:16:56:43 +0800] "PRI * HTTP/2.0" 100 425 "-" "-"
172.68.6.35 1.terarows.com - [21/Feb/2022:16:56:43 +0800] "PRI * HTTP/2.0" 100 2827 "-" "-"
172.68.6.147 1.terarows.com - [21/Feb/2022:16:56:43 +0800] "PRI * HTTP/2.0" 100 425 "-" "-"
162.158.166.9 1.terarows.com - [21/Feb/2022:17:10:30 +0800] "GET / HTTP/2.0" 200 287 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36 OPR/76.0.4017.123"
162.158.166.9 1.terarows.com - [21/Feb/2022:17:10:30 +0800] "POST /fastcgi/json HTTP/2.0" 503 252 "https://1.terarows.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36 OPR/76.0.4017.123"
162.158.166.9 1.terarows.com - [21/Feb/2022:17:10:31 +0800] "POST /fastcgi/json HTTP/2.0" 503 252 "https://1.terarows.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36 OPR/76.0.4017.123"
162.158.166.9 1.terarows.com - [21/Feb/2022:17:10:36 +0800] "PRI * HTTP/2.0" 100 795 "-" "-"
162.158.166.9 1.terarows.com - [21/Feb/2022:17:10:37 +0800] "PRI * HTTP/2.0" 100 425 "-" "-"

Please close and ignore this post I made.

My back end web server application died and caused this error.

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