Load balancer appcookie configuration deprecated in HAproxy

[DagSonsteboSB]

ISSUE TYPE

• Improvement Request

COMPONENT NAME

• ACS 4.11.x VR load balancing with AppCookie stickiness

CLOUDSTACK VERSION

• ACS 4.11.x

CONFIGURATION

• Advanced zone, guest isolated network with LB configuration on public IP

OS / ENVIRONMENT

• N/A

SUMMARY

• AppCookie configuration is deprecated in HAproxy
• https://cbonte.github.io/haproxy-dconv/1.7/configuration.html#appsession

STEPS TO REPRODUCE

• Create new LB rule with AppCookie stickiness
• Observe haproxy logs on VR stating:
  03:59:09 r-1667-VM haproxy[40552]: [ALERT] 090/035909 (40552) : parsing [/etc/haproxy/haproxy.cfg:38] : 'appsession' is not supported anymore, please check the documentation.

EXPECTED RESULTS

• N/A

ACTUAL RESULTS

• Error as above

[yadvr]

The appcookie feature was primary driven by the netscalar implementation (if I recall correctly). Per the haproxy docs As of version 1.6, appsessions was removed. It is more flexible and more convenient to use stick-tables instead, and stick-tables support multi-master replication and data conservation across reloads, which appsessions did not.. We can explore if an upgrade path is possible.

The LB feature needs some overall cleanup and fixing, other than the tcp round-robin (most preferred use-case), SSL off loading etc don't work, as they were primarily netscalar driven in the past. cc @PaulAngus