Cluster Connections: can we cancel randomness and keep the given order? about rascal

[cressie176]

Hi @ea167,

This is not possible at the moment, but I agree it's a good feature.

There are a few options for implementing this, but my preferred one would be

{
  "vhosts": {
    "v1": {
      "connectionStrategy": "fixed",
      "connections": [
         "amqp://user:password@host1/v1",
         "amqp://user:password@host2/v1",
         "amqp://user:password@host3/v1",
      ]
    },
    "v2": {
      "connectionStrategy": "random",
      "connections": [
         "amqp://user:password@host1/v2",
         "amqp://user:password@host2/v2",
         "amqp://user:password@host3/v2",
      ]
    }
  }
}

The connectionStrategy would default to "random" for backwards compatibility. When "fixed" it maintain the order of connections in the array.

Pros

• Simplicity
• Little change
• Supports different strategies per vhost

Cons

• The strategy and url order must be repeated for each vhost if consistent behaviour is desired (partially mitigated by using rascal's defaults feature).
• Specifying a connection strategy, but only having a single connection doesn't make sense

Thoughts?

[cressie176]

Published as [email protected]

[ea167]

Brilliant Stephen @cressie176! Would be perfect!

I guess it only impacts lib/config/configure.js > getConnectionIndex,
where you can test connectionStrategy and branch between Math.random() and a simple sequence increment.

[cressie176]

Yes, thanks what I'm thinking.

[ea167]

Bravo Stephen @cressie176! Amazing! 👏👏👏