Correct logic to allocate volume slots

This commit is contained in:
Chris Lu
2014-04-13 03:06:58 -07:00
parent 6084e7670a
commit 0abd809663

View File

@@ -79,14 +79,12 @@ func (vg *VolumeGrowth) findAndGrow(topo *Topology, option *VolumeGrowOption) (i
return len(servers), err
}
// 1. find the main data node
// 1.1 collect all data nodes that have 1 slots
// 2.2 collect all racks that have rp.SameRackCount+1
// 2.2 collect all data centers that have DiffRackCount+rp.SameRackCount+1
// 2. find rest data nodes
func (vg *VolumeGrowth) findEmptySlotsForOneVolume(topo *Topology, option *VolumeGrowOption) (servers []*DataNode, err error) {
//the algorithms need improvement
//better steps:
// 1. find the main data node
// 1.1 collect all data nodes that have 1 slots
// 2.2 collect all racks that have rp.SameRackCount+1
// 2.2 collect all data centers that have DiffRackCount+rp.SameRackCount+1
// 2. find rest data nodes
//find main datacenter and other data centers
rp := option.ReplicaPlacement
mainDataCenter, otherDataCenters, dc_err := topo.RandomlyPickNodes(rp.DiffDataCenterCount+1, func(node Node) error {
@@ -99,6 +97,21 @@ func (vg *VolumeGrowth) findEmptySlotsForOneVolume(topo *Topology, option *Volum
if node.FreeSpace() < rp.DiffRackCount+rp.SameRackCount+1 {
return fmt.Errorf("Free:%d < Expected:%d", node.FreeSpace(), rp.DiffRackCount+rp.SameRackCount+1)
}
possibleRacksCount := 0
for _, rack := range node.Children() {
possibleDataNodesCount := 0
for _, n := range rack.Children() {
if n.FreeSpace() >= 1 {
possibleDataNodesCount++
}
}
if possibleDataNodesCount >= rp.SameRackCount+1 {
possibleRacksCount++
}
}
if possibleRacksCount < rp.DiffRackCount+1 {
return fmt.Errorf("Only has %d racks with more than %d free data nodes, not enough for %d.", possibleRacksCount, rp.SameRackCount+1, rp.DiffRackCount+1)
}
return nil
})
if dc_err != nil {
@@ -114,17 +127,17 @@ func (vg *VolumeGrowth) findEmptySlotsForOneVolume(topo *Topology, option *Volum
return fmt.Errorf("Free:%d < Expected:%d", node.FreeSpace(), rp.SameRackCount+1)
}
if len(node.Children()) < rp.SameRackCount+1 {
// a bit faster way test failed cases
// a bit faster way to test free racks
return fmt.Errorf("Only has %d data nodes, not enough for %d.", len(node.Children()), rp.SameRackCount+1)
}
possibleDataNodeCount := 0
possibleDataNodesCount := 0
for _, n := range node.Children() {
if n.FreeSpace() >= 1 {
possibleDataNodeCount++
possibleDataNodesCount++
}
}
if possibleDataNodeCount < rp.SameRackCount+1 {
return fmt.Errorf("Only has %d data nodes with a slot, not enough for %d.", possibleDataNodeCount, rp.SameRackCount+1)
if possibleDataNodesCount < rp.SameRackCount+1 {
return fmt.Errorf("Only has %d data nodes with a slot, not enough for %d.", possibleDataNodesCount, rp.SameRackCount+1)
}
return nil
})