Nginx is a popular tool for load balancing and caching. It offers high performance, reliability and flexibility for load balancing through features like upstream modules, health checks, and request distribution methods. It can also improve response times and handle traffic spikes through caching static content and supporting techniques like stale caching.

1. NginxNginx
your load balancer & cacheyour load balancer & cache
MarianMarian HackManHackMan Marinov <mm@1h.com>Marinov <mm@1h.com>
CEO of 1H Ltd.CEO of 1H Ltd.

2. Why load balance with Nginx?Why load balance with Nginx?

3. Why load balance with Nginx?Why load balance with Nginx?
Why not do it with other tools?Why not do it with other tools?

4. ➢ Balancing with iptablesBalancing with iptables
➢ Balancing with iproute2Balancing with iproute2
➢ LinuxVserverLinuxVserver
➢ HAproxyHAproxy
➢ VarnishVarnish
➢ even Apache can do iteven Apache can do it
with mod_proxy_balancerwith mod_proxy_balancer

5. sample.comsample.com
IN A 10.0.0.1IN A 10.0.0.1
IN A 10.0.0.2IN A 10.0.0.2
10.0.0.110.0.0.1 10.0.0.210.0.0.2
DNS balancingDNS balancing

6. sample.comsample.com
IN A 10.0.0.1IN A 10.0.0.1
IN A 10.0.0.2IN A 10.0.0.2
10.0.0.110.0.0.1 10.0.0.210.0.0.2
10.0.0.110.0.0.1
Fault ToleranceFault Tolerance
High AvailabilityHigh Availability

7. ➢Always have at least two LB nodesAlways have at least two LB nodes
➢Use DNS balancingUse DNS balancing
(two A/AAAA) records(two A/AAAA) records
➢Use vrrpd or keepalivedUse vrrpd or keepalived
for floating IPs (on layer 2)for floating IPs (on layer 2)
➢In more complex network setupsIn more complex network setups
Corosync + PacemakerCorosync + Pacemaker
Make sure your infrastructureMake sure your infrastructure
can handle a single LB failurecan handle a single LB failure
(has enough resources CPU, Bandwidth)(has enough resources CPU, Bandwidth)

8. Load balancing with NginxLoad balancing with Nginx

9. Load balancing with NginxLoad balancing with Nginx
➢ upstreamupstream
➢ scgi/uwsgi/fastcgi/memcachedscgi/uwsgi/fastcgi/memcached
➢_pass (using upstream)_pass (using upstream)
➢_next_server_next_server
➢ upstream_conf (commercial)upstream_conf (commercial)
➢ Your own monitoringYour own monitoring

10. Load balancing with NginxLoad balancing with Nginx
synopsis:synopsis:
server IP [options];server IP [options];
upstream static_backend {upstream static_backend {
server 10.0.0.1 fail_timeout=5s max_fails=1;server 10.0.0.1 fail_timeout=5s max_fails=1;
server 10.0.0.2 fail_timeout=5s max_fails=1;server 10.0.0.2 fail_timeout=5s max_fails=1;
keepalive 512;keepalive 512;
}}

11. Load balancing with NginxLoad balancing with Nginx
weight=numberweight=number
max_fails=numbermax_fails=number
fail_timeout=timefail_timeout=time
backupbackup
downdown
max_conns=numbermax_conns=number
resolveresolve
slow_start=timeslow_start=time

12. Load balancing with NginxLoad balancing with Nginx
Request distribution methodRequest distribution method
➢ round-robin (default)round-robin (default)
➢ ip_haship_hash
➢ hashhash
➢ least_connleast_conn
➢ least_timeleast_time header/bytesheader/bytes

13. Load balancing with NginxLoad balancing with Nginx
keepalivekeepalive
health_check [parameters]health_check [parameters]
match namematch name
queue number [timeout=time]queue number [timeout=time]
sticky cookie namesticky cookie name

14. Load balancing with NginxLoad balancing with Nginx
health_check interval=1 uri=/health;health_check interval=1 uri=/health;
# status ok and not in maintenance mode# status ok and not in maintenance mode
match server_ok {match server_ok {
status 200-399;status 200-399;
body !~ "maintenance mode";body !~ "maintenance mode";
}}

15. Caching in NginxCaching in Nginx
➢ Why not cache the static content?Why not cache the static content?
➢ Limited ESI support troughLimited ESI support trough
ngx_http_ssi and ngx_esingx_http_ssi and ngx_esi
➢ Handle traffic extremesHandle traffic extremes
withwith stale cachingstale caching
➢ Reduce response timesReduce response times
If there are people willing to extend ngx_esiIf there are people willing to extend ngx_esi
I would join forces with them!I would join forces with them!

16. Caching in NginxCaching in Nginx
proxy_cache_path /var/lib/nginx/cacheproxy_cache_path /var/lib/nginx/cache
levels=1:2 keys_zone=WP:1024mlevels=1:2 keys_zone=WP:1024m
max_size=2048m;max_size=2048m;
proxy_cache_keyproxy_cache_key
"$host$request_uri $cookie_user";"$host$request_uri $cookie_user";
proxy_cache_valid 200 301 302 2s;proxy_cache_valid 200 301 302 2s;
proxy_cache_use_staleproxy_cache_use_stale
error timeout invalid_header updating;error timeout invalid_header updating;
expires 60s;expires 60s;

17. ?/? Questions ?/??/? Questions ?/?
MarianMarian HackManHackMan MarinovMarinov
<mm@1h.com><mm@1h.com>
CEO of 1H Ltd.CEO of 1H Ltd.

18. Thank Youuuuuu!!!Thank Youuuuuu!!!