func (db *ETCDDB) UpdateDesiredLRP(logger lager.Logger, processGuid string, update *models.DesiredLRPUpdate) error {
logger = logger.Session("update-desired-lrp", lager.Data{"process-guid": processGuid})
logger.Info("starting")
defer logger.Info("complete")
var schedulingInfo *models.DesiredLRPSchedulingInfo
var existingInstances int32
var err error
for i := 0; i < 2; i++ {
var index uint64
schedulingInfo, index, err = db.rawDesiredLRPSchedulingInfo(logger, processGuid)
if err != nil {
logger.Error("failed-to-fetch-scheduling-info", err)
break
}
existingInstances = schedulingInfo.Instances
schedulingInfo.ApplyUpdate(update)
err = db.updateDesiredLRPSchedulingInfo(logger, schedulingInfo, index)
if err != nil {
logger.Error("update-scheduling-info-failed", err)
modelErr := models.ConvertError(err)
if modelErr != models.ErrResourceConflict {
break
}
// Retry on CAS fail
continue
}
break
}
if err != nil {
return err
}
switch diff := schedulingInfo.Instances - existingInstances; {
case diff > 0:
db.startInstanceRange(logger, existingInstances, schedulingInfo.Instances, schedulingInfo)
case diff < 0:
db.stopInstanceRange(logger, schedulingInfo.Instances, existingInstances, schedulingInfo)
case diff == 0:
// this space intentionally left blank
}
return nil
}
func (db *ETCDDB) UpdateDesiredLRP(logger lager.Logger, processGuid string, update *models.DesiredLRPUpdate) (*models.DesiredLRP, error) {
logger.Info("starting")
defer logger.Info("complete")
var schedulingInfo *models.DesiredLRPSchedulingInfo
var err error
var beforeDesiredLRP *models.DesiredLRP
for i := 0; i < 2; i++ {
var index uint64
beforeDesiredLRP, index, err = db.rawDesiredLRPByProcessGuid(logger, processGuid)
if err != nil {
logger.Error("failed-to-fetch-desired-lrp", err)
break
}
schedulingInfoValue := beforeDesiredLRP.DesiredLRPSchedulingInfo()
schedulingInfo = &schedulingInfoValue
schedulingInfo.ApplyUpdate(update)
err = db.updateDesiredLRPSchedulingInfo(logger, schedulingInfo, index)
if err != nil {
logger.Error("update-scheduling-info-failed", err)
modelErr := models.ConvertError(err)
if modelErr != models.ErrResourceConflict {
break
}
// Retry on CAS fail
continue
}
break
}
if err != nil {
return nil, err
}
return beforeDesiredLRP, nil
}
