Changing swarm loadbalancing algorithm

Docker Engine Swarm
1

Hi all
Is it possible to alter the loadbalancing algorithm used by swarm for containers/services? I believe it defaults to round-robin. I’d live to know how to change it to, for example, least connections or least busiest, if possible. I do hope it’s possible.
Thank you

2

As far as I know there are VIP and DNSRR.

3

Loadbalancing could mean two things:

  • how the scheduler places tasks on nodes
    • there is only one scheduling algorithm, which can be controlled by deployment mode global or replicated, and the target nodes can be restricted with placement constraints.
  • how the network communication is forwarded to the service tasks.
    • vip:
      • the swarn service name resolves to the virtual IP of the service (based on LVS/IPVS) and loadbalances to the service task containers.
      • has problems with long-lived connections - by default connections will be closed after 900 seconds.
    • dnsrr:
      • the swarm service name resolves to a multi-value response containing the ips of all service task containers of this service.
      • suited for long-lived connections.
      • will result in the opposite of load distribution, if the client application caches the resulting ip of a dns lookup, and re-uses it forever.

So I am afraid what you are looking for does not exist in swarm.

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