ceph-csi/internal/util/read_affinity.go
Praveen M 4d466843b9 cephfs: add read affinity mount option
This commit makes use of crush location labels from node
labels to supply `crush_location` and `read_from_replica=localize`
options during mount. Using these options, cephfs
will be able to redirect reads to the closest OSD,
improving performance.

Signed-off-by: Praveen M <m.praveen@ibm.com>
2023-11-22 13:13:01 +00:00

78 lines
2.2 KiB
Go

/*
Copyright 2023 The Ceph-CSI Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package util
import (
"fmt"
"strings"
)
// ConstructReadAffinityMapOption constructs a read affinity map option based on the provided crushLocationMap.
// It appends crush location labels in the format
// "read_from_replica=localize,crush_location=label1:value1|label2:value2|...".
func ConstructReadAffinityMapOption(crushLocationMap map[string]string) string {
if len(crushLocationMap) == 0 {
return ""
}
var b strings.Builder
b.WriteString("read_from_replica=localize,crush_location=")
first := true
for key, val := range crushLocationMap {
if first {
b.WriteString(fmt.Sprintf("%s:%s", key, val))
first = false
} else {
b.WriteString(fmt.Sprintf("|%s:%s", key, val))
}
}
return b.String()
}
// GetReadAffinityMapOptions retrieves the readAffinityMapOptions from the CSI config file if it exists.
// If not, it falls back to returning the `cliReadAffinityMapOptions` from the command line.
// If neither of these options is available, it returns an empty string.
func GetReadAffinityMapOptions(
csiConfigFile, clusterID, cliReadAffinityMapOptions string,
nodeLabels map[string]string,
) (string, error) {
var (
err error
configReadAffinityEnabled bool
configCrushLocationLabels string
)
configReadAffinityEnabled, configCrushLocationLabels, err = GetCrushLocationLabels(csiConfigFile, clusterID)
if err != nil {
return "", err
}
if !configReadAffinityEnabled {
return "", nil
}
if configCrushLocationLabels == "" {
return cliReadAffinityMapOptions, nil
}
crushLocationMap := GetCrushLocationMap(configCrushLocationLabels, nodeLabels)
readAffinityMapOptions := ConstructReadAffinityMapOption(crushLocationMap)
return readAffinityMapOptions, nil
}