// RULES FOR DERIVING THE PG NUM
// if no of osds <= 5 then
// no of PGs = 128
// if no of osds > 5 and <= 10 then
// no of PGs = 512
// if no of osds > 10 and <= 50 then
// no of PGs = 4096
// if no of osds > 50 then
// no of PGs = (Avg Target PGs per OSD * No of OSDs * Data Percentage) / Replica Count
// -- where
// Data Percentage = Target Allocation Size / Max Allocation Size
// -- where
// Target Allocation Size - provided in request
// Max Allocation Size = ((Average OSD Size * No of OSDs) / Replica Count) * Max Utilization Factor
// -- where Max Utilization Factor is set as 0.8
// Finally round this value of next 2's power
func DerivePgNum(clusterId uuid.UUID, size string, replicaCount int, profile string) uint {
// Get the no of OSDs in the cluster
sessionCopy := db.GetDatastore().Copy()
defer sessionCopy.Close()
coll := sessionCopy.DB(conf.SystemConfig.DBConfig.Database).C(models.COLL_NAME_STORAGE_LOGICAL_UNITS)
var slus []models.StorageLogicalUnit
if err := coll.Find(bson.M{"clusterid": clusterId, "type": models.CEPH_OSD, "storageprofile": profile}).All(&slus); err != nil {
return uint(DEFAULT_PG_NUM)
}
osdsNum := len(slus)
// Calculate the pgnum value
if osdsNum <= 5 {
return uint(DEFAULT_PG_NUM)
}
if osdsNum <= 10 {
return uint(512)
}
if osdsNum <= 50 {
return uint(4096)
}
avgOsdSize := avg_osd_size(slus) / 1024
maxAllocSize := (avgOsdSize * float64(len(slus)) / float64(replicaCount)) * float64(MAX_UTILIZATION_PCNT) / 100
pcntData := float64(utils.SizeFromStr(size)) / float64(maxAllocSize)
pgnum := float64(float64(TARGET_PGS_PER_OSD)*float64(len(slus))*pcntData) / float64(replicaCount)
derivedPgNum := utils.NextTwosPower(uint(pgnum))
if derivedPgNum < uint(osdsNum) {
// Consider next 2's power value
newPgNum := osdsNum / replicaCount
derivedPgNum = utils.NextTwosPower(uint(newPgNum))
}
return derivedPgNum
}
func (s *CephProvider) GetDiskHierarchy(req models.RpcRequest, resp *models.RpcResponse) error {
var request models.DiskHierarchyRequest
ctxt := req.RpcRequestContext
if err := json.Unmarshal(req.RpcRequestData, &request); err != nil {
logger.Get().Error(fmt.Sprintf("%s-Unbale to parse the disk hierarchy request. error: %v", ctxt, err))
*resp = utils.WriteResponse(http.StatusBadRequest, fmt.Sprintf("Unbale to parse the request. error: %v", err))
return err
}
if request.JournalSize == "" {
request.JournalSize = fmt.Sprintf("%dMB", JOURNALSIZE)
}
nodes, err := util.GetNodes(request.ClusterNodes)
if err != nil {
logger.Get().Error(
"%s-Error getting nodes list from DB for cluster %s. error: %v",
ctxt,
request.ClusterName,
err)
return err
}
hierarchy := make(map[string]map[string]string)
var storageSize float64
for _, requestNode := range request.ClusterNodes {
disksMap := make(map[string]string)
uuid, err := uuid.Parse(requestNode.NodeId)
if err != nil {
logger.Get().Error(
"%s-Error parsing node id: %s for cluster: %s. error: %v",
ctxt,
requestNode.NodeId,
request.ClusterName,
err)
continue
}
devices := make(map[string]models.Disk)
storageNode := nodes[*uuid]
// Form a map of storage node disks
var nodeDisksMap map[string]models.Disk = make(map[string]models.Disk)
for _, storageDisk := range storageNode.StorageDisks {
nodeDisksMap[storageDisk.Name] = storageDisk
}
for diskName, storageDisk := range nodeDisksMap {
for idx := 0; idx < len(requestNode.Devices); idx++ {
if diskName == requestNode.Devices[idx].Name {
devices[requestNode.Devices[idx].Name] = storageDisk
}
}
}
// Utility function returns value in MB so multiply by 1024 to make is bytes
jSize := utils.SizeFromStr(request.JournalSize) * float64(1024)
diskWithJournalMapped := getDiskWithJournalMapped(devices, jSize)
for disk, journal := range diskWithJournalMapped {
disksMap[disk] = journal.JournalDisk
for _, storageDisk := range storageNode.StorageDisks {
if storageDisk.Name == disk {
storageSize += storageDisk.Size
}
}
}
hierarchy[requestNode.NodeId] = disksMap
}
retVal := models.DiskHierarchyDetails{
ClusterName: request.ClusterName,
Hierarchy: hierarchy,
StorageSize: storageSize,
}
result, err := json.Marshal(retVal)
if err != nil {
logger.Get().Error(
"%s-Error forming the output for get disk hierarchy of cluster: %s. error: %v",
ctxt,
request.ClusterName,
err)
*resp = utils.WriteResponse(
http.StatusInternalServerError,
fmt.Sprintf(
"Error forming the output. error: %v",
err))
return err
}
*resp = utils.WriteResponseWithData(http.StatusOK, "", result)
return nil
}