HAProxy

Introductory talk about HAProxy, given on September 17th 2015 at ZgPHP Meetup in net.culture club MaMa.

Transcript

1. HAProxy  
   Goran Jurić
   ZgPHP Meetup
   17th September, 2015
    
   

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2. •  The  Reliable,  High  Performance  TCP/HTTP  
   Load  Balancer
   •  V1.5  current  stable  release  
   

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3. It allows you to  
   •  Distribute the load across several
   servers
   •  Failover to a backup server (HA)
   •  Take the server offline for maintenance
   •  Multiple load balancing algorithms
   •  Protect backend servers
   

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4. TCP  
   •  Layer 4 proxy
   •  Load balance any TCP/IP traffic
   

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5. HTTP proxy  
   •  Layer 7 proxy
   •  Redirect to a specific server based on
   different parameters (ACLs)
   •  Sticky sessions
   

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6. Configuration  
   •  global
   •  default
   •  frontends
   •  backends  
   

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7. Example  
   frontend www!
   bind *:80!
   bind *:443 ssl crt /etc/ssl/private/your-cert.pem!
   redirect scheme https if !{ ssl_fc }!
   mode http!
   default_backend app-servers!
   !
   backend app-servers!
   !mode http!
   !option forwardfor!
   !option httpchk GET /test-url!
   !cookie PHPSESSID prefix nocache!
   !server app1 :80 check inter 12000 rise 3 fall 3 cookie app1!
   !server app2 :80 check inter 12000 rise 3 fall 3 cookie app2!
   

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8. ACLs
    
   •  acl network_allowed src 20.30.40.50 20.30.40.40 !
   •  acl restricted_page path_beg /admin !
   •  acl restricted_page path_beg /helpdesk !
   •  block if restricted_page !network_allowed!
   •  acl  is_blog  url_beg  /blog
   •  use_backend  some-other-backend  if  is_blog
   

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9. Important  
   •  App servers sees haproxy IP
   – nginx:

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10. SSL config
     
    Mozilla  SSL  ConfiguraFon  Generator
    
    hHps://mozilla.github.io/server-­‐side-­‐tls/ssl-­‐config-­‐generator/
    

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11. HA in HAProxy  
    •  What if the server running HAProxy
    fails?
    •  Floating IP address
    •  keepalived/heartbeat/pacemaker  
    

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12. HA in HAProxy  
    

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13. HA in your application  
    •  Session storage
    – Use a clustered session storage
    – Do not use sessions
    •  Clustered database
    •  Rolling deployments  
    

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14. GUI  
    

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15. HATop  
    

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16. Why not nginx  
    •  General TCP load balancer
    •  Out of band health checks
    •  Admin interface to manage servers
    •  Powerful ACLs
    

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