Maintaining a minimum active number of resources.

[frank-weindel]

I'm having trouble getting my pool keep a minimum number of resources alive. Essentially, I want to have at least 4 available at all times and spawn up to 4 more when load becomes heavier.

This is my code:

this.generatorPool = poolModule.Pool({
    name: 'generator-pool',
    create: function (resolveResource) {
      var generator = new Generator();
      generator.start().then(
        // Generator load successful
        function() {
          resolveResource(null, generator);
        },
        // Generator failed to load
        function () {
          resolveResource(new Error('Failed to load generator'));
        }
      );
    },
    destroy: function (generator) {
      console.log('DESTROYING THE GENERATOR)
      generator.stop();
    },
    max: 8,
    min: 4,
    refreshIdle: false,
    idleTimeoutMillis: 30000
  });

For some reason the first 4 resources are still being destroyed after 30 seconds. What could be up?

[sandfox]

This looks like intended behaviour.

Once each of the first 4 resources are destroyed are they being replaced by another set of resources? (i.e does the pool always have 4 resources in it, because that should be what is happening)
The resources are getting destroyed after 30 seconds because of the idleTimeoutMillis: 30000.

[frank-weindel]

Looking at it closer I see the problem is different than I originally thought. When I have the minimum set to 4 the pool does start to spawn 4 resources when its created. However, immediately after the pool creation I call acquire 4 times. This starts up an ADDITIONAL 4 resources instead of waiting for the first 4 to finish initializing and using them. Those 4 additional resources were what I was seeing get destroyed. Its not a huge deal for me since this can only happen at startup.

I can understand fixing that issue might not be worth the complexity.