NGINX Live EP.5 NGINX Health Checks Slide

NGINX
HEALTH CHECKS
NGINX LIVE EP.5
SUPACHAI JATURAPROM (TUM)
AUG 2020
NGINX USER GROUP: THAILAND CHAPTER
WWW.MEETUP.COM/TH-TH/NGINX-THAILAND

NGINX
HEALTH CHECKS
AGENDA
Why ? Health Checks
TCP Health Checks
HTTP Health Checks
UDP Health Checks
Active Health Checks
Passive Health Checks
NGINX User Group: Thailand Chapter
www.meetup.com/th-TH/NGINX-Thailand
NGINX Live EP.5
Supachai Jaturaprom (Tum)

WHY ? HEALTH CHECKS (1)
Client 1
Load Balance
Host 1
Host 2
Host 3
Client 2
Client 3
NGINX Live EP.5

Client 1
Load Balance
Host 1
Host 2
Host 3
Client 2
Client 3
NGINX Live EP.5

Client 1
Load Balance
Host 1
Host 2
Host 3
Client 2
Client 3
Health checks
Health checks
Health checks
Data Traffic
Data Traffic
Data Traffic
NGINX Live EP.5

Load Balance
Client 1 Host 1
Host 2
Host 3
Client 2
Client 3
Health checks
Health checks
Health checks
Data Traffic
Data Traffic
Data Traffic
NGINX Live EP.5

Client 1
Load Balance
Host 1
Host 2Client 2
Client 3
Health checks
Health checks
Health checks
Host 3
Data Traffic
Data Traffic
Data Traffic
NGINX Live EP.5

Client 1
Load Balance
Host 1
Host 2
Host 3
Client 2
Client 3
Health checks
Health checks
Health checks
Data Traffic
Data Traffic
Data Traffic
healthy
healthy
healthy
NGINX Live EP.5

Load Balance
Host 1
Host 2
Host 3
Client 1
Health checks
Health checks
Health checks
Data Traffic
ACTIVE HEALTH CHECK
GET / Return 200 OK
healthy
healthy
healthy
NGINX Live EP.5

Load Balance
Host 1
Host 2
Host 3
Client 1
Data Traffic
PASSIVE HEALTH CHECK
500 Error
หรือ Timeout
Client 2
Data Traffic
unhealthy
healthy
healthy
NGINX Live EP.5

HTTPS HEALTH CHECKS (1)
upstream backend {
server backend1.example.com;
}
server {
location / {
proxy_pass http://backend;
health_check;
}
}
by default, every five seconds
a request for “/” to each server in
the backend group.
If any communication error or
timeout occurs (outside 200-399)
the health check fails.
The server is marked as unhealthy.
NGINX Live EP.5

server {
location / {
health_check port=9999 interval=10 fails=3 passes=2
uri=/some/path;
}
} port = คือ การระบุ port number ทีใช้ health checks (default port server)
interval = คือ การระบุระยะเวลาในการทํา health checks (default 5s)
fails= คือ จํานวนการ fails ทีจะทําการ marking ว่า unhealthy (default 1)
passes= คือ จํานวนการ success ทีจะทําการ marking ว่า healthy (default 1)
uri= คือ การระบุ uri path (default path "/" )
http://backend1.exmaple.naja/i/love/nginx
marking unhealthy = 10x3 = 30 วินาที
marking healthy = 10x2 = 20 วินาที
NGINX Live EP.5

http {
...........
match server_ok {
status 200-399;
body !~ "maintenance mode";
}
server {
...........
location / {
health_check match=server_ok;
}
Here the health check is passed if
the status code of the response is
in the range 200–399, and its
body does not contain the string
"maintenance mode".
NGINX Live EP.5

TCP HEALTH CHECKS (1)
stream {
#...
server {
listen 12345;
proxy_pass stream_backend;
health_check port=12346 interval=10 passes=2 fails=3;
health_check_timeout 5s;
}
}
** health_check_timeout directive is overrides proxy_timeout directive.
NGINX Live EP.5

TCP HEALTH CHECKS (2)
stream {
#...
upstream stream_backend {
..........
}
match http {
send "GET / HTTP/1.0rnHost: localhostrnrn";
expect ~* "200 OK";
}
server {
listen 12345;
health_check match=http;
proxy_pass stream_backend;
}
send คือ text string หรือ hex (/x) ทีส่งออกไป
expect คือ Literal string หรือ regex ทีคาดหวังจะได้รับ
NGINX Live EP.5

UDP HEALTH CHECKS (1)
stream {
#...
server {
listen 53 udp;
proxy_pass dns_upstream;
health_check interval=20 passes=2 fails=2 udp;
}
#...
}
** udp parameter specifies that the UDP protocol should be used
for health checks instead of the default TCP protocol.
NGINX Live EP.5

UDP HEALTH CHECKS (2)
stream {
#...
match dns {
send x00x2ax00x00x00x01x00x00x00x00x00x00x03.....;
expect ~* "health.is.good";
}
server {
listen 53 udp;
proxy_pass dns_upstream;
health_check match=udp_test udp;
}
#...
}
NGINX Live EP.5

SERVER SLOW-START
upstream backend {
server backend1.example.com slow_start=30s;
server 127.255.255.254 backup;
}
slow‑start allows an upstream server to gradually recover its weight from 0 to
its nominal value after it has been recovered or became available. by default is
0, that mean disable slow-start.
NGINX Live EP.5

NGINX
HEALTH CHECKS
SUMMARY
Why ? Health Checks
Active Health Checks
Passive Health Checks
NGINX Live EP.5

THANKS YOUR
NGINX LIVE EP.5
SUPACHAI JATURAPROM (TUM)

NGINX Live EP.5 NGINX Health Checks Slide

Recommended

Recommended

More Related Content

Similar to NGINX Live EP.5 NGINX Health Checks Slide

Similar to NGINX Live EP.5 NGINX Health Checks Slide (20)

Recently uploaded

Recently uploaded (20)

NGINX Live EP.5 NGINX Health Checks Slide