func SystemCapacity(rw http.ResponseWriter, r *http.Request) *httperr.Error {
capacity, err := provider.CapacityGet()
if err != nil {
return httperr.Server(err)
}
return RenderJson(rw, capacity)
}
// Update Process Parameters for Count and Memory
// Expects -1 for count or memory to indicate no change, since count=0 is valid
func SetFormation(app, process string, count, memory int64) error {
a, err := GetApp(app)
if err != nil {
return err
}
rel, err := GetRelease(a.Name, a.Release)
if err != nil {
return err
}
m, err := LoadManifest(rel.Manifest, a)
if err != nil {
return err
}
me := m.Entry(process)
if me == nil {
return fmt.Errorf("no such process: %s", process)
}
capacity, err := provider.CapacityGet()
if err != nil {
return err
}
params := map[string]string{}
// if not -1, set new parameter values
if count >= 0 {
params[fmt.Sprintf("%sDesiredCount", UpperName(process))] = fmt.Sprintf("%d", count)
}
if memory > 0 {
if memory > capacity.InstanceMemory {
return fmt.Errorf("requested memory %d greater than instance size %d", memory, capacity.InstanceMemory)
}
params[fmt.Sprintf("%sMemory", UpperName(process))] = fmt.Sprintf("%d", memory)
}
NotifySuccess("release:scale", map[string]string{
"app": rel.App,
"id": rel.Id,
})
return a.UpdateParams(params)
}
func autoscaleRack() {
log := logger.New("ns=workers.autoscale at=autoscaleRack")
capacity, err := provider.CapacityGet()
if err != nil {
log.Log("fn=models.GetSystemCapacity err=%q", err)
return
}
log.Log("autoscale=%t", autoscale)
if !autoscale {
return
}
system, err := provider.SystemGet()
if err != nil {
log.Log("fn=models.GetSystem err=%q", err)
return
}
// calaculate instance requirements based on total process memory needed divided by the memory
// on an individual instance
instances := int(math.Ceil(float64(capacity.ProcessMemory) / float64(capacity.InstanceMemory)))
// instance count cant be less than 2
if instances < 2 {
instances = 2
}
// instance count must be at least maxconcurrency+1
if instances < (int(capacity.ProcessWidth) + 1) {
instances = int(capacity.ProcessWidth) + 1
}
log.Log("process.memory=%d instance.memory=%d instances=%d change=%d", capacity.ProcessMemory, capacity.InstanceMemory, instances, (instances - system.Count))
// if no change then exit
if system.Count == instances {
return
}
system.Count = instances
err = provider.SystemSave(*system)
if err != nil {
log.Log("fn=system.Save err=%q", err)
return
}
}