minio/cmd/admin-rpc-client.go
Frank Wessels 46897b1100 Name return values to prevent the need (and unnecessary code bloat) (#4576)
This is done to explicitly instantiate objects for every return statement.
2017-06-21 19:53:09 -07:00

626 lines
17 KiB
Go

/*
* Minio Cloud Storage, (C) 2014, 2015, 2016, 2017 Minio, Inc.
*
* 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 cmd
import (
"encoding/json"
"errors"
"fmt"
"net"
"os"
"path"
"path/filepath"
"reflect"
"sort"
"sync"
"time"
"github.com/minio/minio-go/pkg/set"
)
const (
// Admin service names
serviceRestartRPC = "Admin.Restart"
listLocksRPC = "Admin.ListLocks"
reInitDisksRPC = "Admin.ReInitDisks"
serverInfoDataRPC = "Admin.ServerInfoData"
getConfigRPC = "Admin.GetConfig"
writeTmpConfigRPC = "Admin.WriteTmpConfig"
commitConfigRPC = "Admin.CommitConfig"
)
// localAdminClient - represents admin operation to be executed locally.
type localAdminClient struct {
}
// remoteAdminClient - represents admin operation to be executed
// remotely, via RPC.
type remoteAdminClient struct {
*AuthRPCClient
}
// adminCmdRunner - abstracts local and remote execution of admin
// commands like service stop and service restart.
type adminCmdRunner interface {
Restart() error
ListLocks(bucket, prefix string, duration time.Duration) ([]VolumeLockInfo, error)
ReInitDisks() error
ServerInfoData() (ServerInfoData, error)
GetConfig() ([]byte, error)
WriteTmpConfig(tmpFileName string, configBytes []byte) error
CommitConfig(tmpFileName string) error
}
// Restart - Sends a message over channel to the go-routine
// responsible for restarting the process.
func (lc localAdminClient) Restart() error {
globalServiceSignalCh <- serviceRestart
return nil
}
// ListLocks - Fetches lock information from local lock instrumentation.
func (lc localAdminClient) ListLocks(bucket, prefix string, duration time.Duration) ([]VolumeLockInfo, error) {
return listLocksInfo(bucket, prefix, duration), nil
}
// Restart - Sends restart command to remote server via RPC.
func (rc remoteAdminClient) Restart() error {
args := AuthRPCArgs{}
reply := AuthRPCReply{}
return rc.Call(serviceRestartRPC, &args, &reply)
}
// ListLocks - Sends list locks command to remote server via RPC.
func (rc remoteAdminClient) ListLocks(bucket, prefix string, duration time.Duration) ([]VolumeLockInfo, error) {
listArgs := ListLocksQuery{
bucket: bucket,
prefix: prefix,
duration: duration,
}
var reply ListLocksReply
if err := rc.Call(listLocksRPC, &listArgs, &reply); err != nil {
return nil, err
}
return reply.volLocks, nil
}
// ReInitDisks - There is nothing to do here, heal format REST API
// handler has already formatted and reinitialized the local disks.
func (lc localAdminClient) ReInitDisks() error {
return nil
}
// ReInitDisks - Signals peers via RPC to reinitialize their disks and
// object layer.
func (rc remoteAdminClient) ReInitDisks() error {
args := AuthRPCArgs{}
reply := AuthRPCReply{}
return rc.Call(reInitDisksRPC, &args, &reply)
}
// ServerInfoData - Returns the server info of this server.
func (lc localAdminClient) ServerInfoData() (sid ServerInfoData, e error) {
if globalBootTime.IsZero() {
return sid, errServerNotInitialized
}
// Build storage info
objLayer := newObjectLayerFn()
if objLayer == nil {
return sid, errServerNotInitialized
}
storage := objLayer.StorageInfo()
var arns []string
for queueArn := range globalEventNotifier.GetAllExternalTargets() {
arns = append(arns, queueArn)
}
return ServerInfoData{
StorageInfo: storage,
ConnStats: globalConnStats.toServerConnStats(),
HTTPStats: globalHTTPStats.toServerHTTPStats(),
Properties: ServerProperties{
Uptime: UTCNow().Sub(globalBootTime),
Version: Version,
CommitID: CommitID,
SQSARN: arns,
Region: serverConfig.GetRegion(),
},
}, nil
}
// ServerInfo - returns the server info of the server to which the RPC call is made.
func (rc remoteAdminClient) ServerInfoData() (sid ServerInfoData, e error) {
args := AuthRPCArgs{}
reply := ServerInfoDataReply{}
err := rc.Call(serverInfoDataRPC, &args, &reply)
if err != nil {
return sid, err
}
return reply.ServerInfoData, nil
}
// GetConfig - returns config.json of the local server.
func (lc localAdminClient) GetConfig() ([]byte, error) {
if serverConfig == nil {
return nil, errors.New("config not present")
}
return json.Marshal(serverConfig)
}
// GetConfig - returns config.json of the remote server.
func (rc remoteAdminClient) GetConfig() ([]byte, error) {
args := AuthRPCArgs{}
reply := ConfigReply{}
if err := rc.Call(getConfigRPC, &args, &reply); err != nil {
return nil, err
}
return reply.Config, nil
}
// WriteTmpConfig - writes config file content to a temporary file on
// the local server.
func (lc localAdminClient) WriteTmpConfig(tmpFileName string, configBytes []byte) error {
return writeTmpConfigCommon(tmpFileName, configBytes)
}
// WriteTmpConfig - writes config file content to a temporary file on
// a remote node.
func (rc remoteAdminClient) WriteTmpConfig(tmpFileName string, configBytes []byte) error {
wArgs := WriteConfigArgs{
TmpFileName: tmpFileName,
Buf: configBytes,
}
err := rc.Call(writeTmpConfigRPC, &wArgs, &WriteConfigReply{})
if err != nil {
errorIf(err, "Failed to write temporary config file.")
return err
}
return nil
}
// CommitConfig - Move the new config in tmpFileName onto config.json
// on a local node.
func (lc localAdminClient) CommitConfig(tmpFileName string) error {
configFile := getConfigFile()
tmpConfigFile := filepath.Join(getConfigDir(), tmpFileName)
err := os.Rename(tmpConfigFile, configFile)
errorIf(err, fmt.Sprintf("Failed to rename %s to %s", tmpConfigFile, configFile))
return err
}
// CommitConfig - Move the new config in tmpFileName onto config.json
// on a remote node.
func (rc remoteAdminClient) CommitConfig(tmpFileName string) error {
cArgs := CommitConfigArgs{
FileName: tmpFileName,
}
cReply := CommitConfigReply{}
err := rc.Call(commitConfigRPC, &cArgs, &cReply)
if err != nil {
errorIf(err, "Failed to rename config file.")
return err
}
return nil
}
// adminPeer - represents an entity that implements Restart methods.
type adminPeer struct {
addr string
cmdRunner adminCmdRunner
}
// type alias for a collection of adminPeer.
type adminPeers []adminPeer
// makeAdminPeers - helper function to construct a collection of adminPeer.
func makeAdminPeers(endpoints EndpointList) (adminPeerList adminPeers) {
thisPeer := globalMinioAddr
if globalMinioHost == "" {
thisPeer = net.JoinHostPort("localhost", globalMinioPort)
}
adminPeerList = append(adminPeerList, adminPeer{
thisPeer,
localAdminClient{},
})
hostSet := set.CreateStringSet(globalMinioAddr)
cred := serverConfig.GetCredential()
serviceEndpoint := path.Join(minioReservedBucketPath, adminPath)
for _, host := range GetRemotePeers(endpoints) {
if hostSet.Contains(host) {
continue
}
hostSet.Add(host)
adminPeerList = append(adminPeerList, adminPeer{
addr: host,
cmdRunner: &remoteAdminClient{newAuthRPCClient(authConfig{
accessKey: cred.AccessKey,
secretKey: cred.SecretKey,
serverAddr: host,
serviceEndpoint: serviceEndpoint,
secureConn: globalIsSSL,
serviceName: "Admin",
})},
})
}
return adminPeerList
}
// Initialize global adminPeer collection.
func initGlobalAdminPeers(endpoints EndpointList) {
globalAdminPeers = makeAdminPeers(endpoints)
}
// invokeServiceCmd - Invoke Restart command.
func invokeServiceCmd(cp adminPeer, cmd serviceSignal) (err error) {
switch cmd {
case serviceRestart:
err = cp.cmdRunner.Restart()
}
return err
}
// sendServiceCmd - Invoke Restart command on remote peers
// adminPeer followed by on the local peer.
func sendServiceCmd(cps adminPeers, cmd serviceSignal) {
// Send service command like stop or restart to all remote nodes and finally run on local node.
errs := make([]error, len(cps))
var wg sync.WaitGroup
remotePeers := cps[1:]
for i := range remotePeers {
wg.Add(1)
go func(idx int) {
defer wg.Done()
// we use idx+1 because remotePeers slice is 1 position shifted w.r.t cps
errs[idx+1] = invokeServiceCmd(remotePeers[idx], cmd)
}(i)
}
wg.Wait()
errs[0] = invokeServiceCmd(cps[0], cmd)
}
// listPeerLocksInfo - fetch list of locks held on the given bucket,
// matching prefix held longer than duration from all peer servers.
func listPeerLocksInfo(peers adminPeers, bucket, prefix string, duration time.Duration) ([]VolumeLockInfo, error) {
// Used to aggregate volume lock information from all nodes.
allLocks := make([][]VolumeLockInfo, len(peers))
errs := make([]error, len(peers))
var wg sync.WaitGroup
localPeer := peers[0]
remotePeers := peers[1:]
for i, remotePeer := range remotePeers {
wg.Add(1)
go func(idx int, remotePeer adminPeer) {
defer wg.Done()
// `remotePeers` is right-shifted by one position relative to `peers`
allLocks[idx], errs[idx] = remotePeer.cmdRunner.ListLocks(bucket, prefix, duration)
}(i+1, remotePeer)
}
wg.Wait()
allLocks[0], errs[0] = localPeer.cmdRunner.ListLocks(bucket, prefix, duration)
// Summarizing errors received for ListLocks RPC across all
// nodes. N B the possible unavailability of quorum in errors
// applies only to distributed setup.
errCount, err := reduceErrs(errs, []error{})
if err != nil {
if errCount >= (len(peers)/2 + 1) {
return nil, err
}
return nil, InsufficientReadQuorum{}
}
// Group lock information across nodes by (bucket, object)
// pair. For readability only.
paramLockMap := make(map[nsParam][]VolumeLockInfo)
for _, nodeLocks := range allLocks {
for _, lockInfo := range nodeLocks {
param := nsParam{
volume: lockInfo.Bucket,
path: lockInfo.Object,
}
paramLockMap[param] = append(paramLockMap[param], lockInfo)
}
}
groupedLockInfos := []VolumeLockInfo{}
for _, volLocks := range paramLockMap {
groupedLockInfos = append(groupedLockInfos, volLocks...)
}
return groupedLockInfos, nil
}
// reInitPeerDisks - reinitialize disks and object layer on peer servers to use the new format.
func reInitPeerDisks(peers adminPeers) error {
errs := make([]error, len(peers))
// Send ReInitDisks RPC call to all nodes.
// for local adminPeer this is a no-op.
wg := sync.WaitGroup{}
for i, peer := range peers {
wg.Add(1)
go func(idx int, peer adminPeer) {
defer wg.Done()
errs[idx] = peer.cmdRunner.ReInitDisks()
}(i, peer)
}
wg.Wait()
return nil
}
// uptimeSlice - used to sort uptimes in chronological order.
type uptimeSlice []struct {
err error
uptime time.Duration
}
func (ts uptimeSlice) Len() int {
return len(ts)
}
func (ts uptimeSlice) Less(i, j int) bool {
return ts[i].uptime < ts[j].uptime
}
func (ts uptimeSlice) Swap(i, j int) {
ts[i], ts[j] = ts[j], ts[i]
}
// getPeerUptimes - returns the uptime since the last time read quorum
// was established on success. Otherwise returns errXLReadQuorum.
func getPeerUptimes(peers adminPeers) (time.Duration, error) {
// In a single node Erasure or FS backend setup the uptime of
// the setup is the uptime of the single minio server
// instance.
if !globalIsDistXL {
return UTCNow().Sub(globalBootTime), nil
}
uptimes := make(uptimeSlice, len(peers))
// Get up time of all servers.
wg := sync.WaitGroup{}
for i, peer := range peers {
wg.Add(1)
go func(idx int, peer adminPeer) {
defer wg.Done()
serverInfoData, rpcErr := peer.cmdRunner.ServerInfoData()
uptimes[idx].uptime, uptimes[idx].err = serverInfoData.Properties.Uptime, rpcErr
}(i, peer)
}
wg.Wait()
// Sort uptimes in chronological order.
sort.Sort(uptimes)
// Pick the readQuorum'th uptime in chronological order. i.e,
// the time at which read quorum was (re-)established.
readQuorum := len(uptimes) / 2
validCount := 0
latestUptime := time.Duration(0)
for _, uptime := range uptimes {
if uptime.err != nil {
errorIf(uptime.err, "Unable to fetch uptime")
continue
}
validCount++
if validCount >= readQuorum {
latestUptime = uptime.uptime
break
}
}
// Less than readQuorum "Admin.Uptime" RPC call returned
// successfully, so read-quorum unavailable.
if validCount < readQuorum {
return time.Duration(0), InsufficientReadQuorum{}
}
return latestUptime, nil
}
// getPeerConfig - Fetches config.json from all nodes in the setup and
// returns the one that occurs in a majority of them.
func getPeerConfig(peers adminPeers) ([]byte, error) {
if !globalIsDistXL {
return peers[0].cmdRunner.GetConfig()
}
errs := make([]error, len(peers))
configs := make([][]byte, len(peers))
// Get config from all servers.
wg := sync.WaitGroup{}
for i, peer := range peers {
wg.Add(1)
go func(idx int, peer adminPeer) {
defer wg.Done()
configs[idx], errs[idx] = peer.cmdRunner.GetConfig()
}(i, peer)
}
wg.Wait()
// Find the maximally occurring config among peers in a
// distributed setup.
serverConfigs := make([]serverConfigV13, len(peers))
for i, configBytes := range configs {
if errs[i] != nil {
continue
}
// Unmarshal the received config files.
err := json.Unmarshal(configBytes, &serverConfigs[i])
if err != nil {
errorIf(err, "Failed to unmarshal serverConfig from ", peers[i].addr)
return nil, err
}
}
configJSON, err := getValidServerConfig(serverConfigs, errs)
if err != nil {
errorIf(err, "Unable to find a valid server config")
return nil, traceError(err)
}
// Return the config.json that was present quorum or more
// number of disks.
return json.Marshal(configJSON)
}
// getValidServerConfig - finds the server config that is present in
// quorum or more number of servers.
func getValidServerConfig(serverConfigs []serverConfigV13, errs []error) (scv serverConfigV13, e error) {
// majority-based quorum
quorum := len(serverConfigs)/2 + 1
// Count the number of disks a config.json was found in.
configCounter := make([]int, len(serverConfigs))
// We group equal serverConfigs by the lowest index of the
// same value; e.g, let us take the following serverConfigs
// in a 4-node setup,
// serverConfigs == [c1, c2, c1, c1]
// configCounter == [3, 1, 0, 0]
// c1, c2 are the only distinct values that appear. c1 is
// identified by 0, the lowest index it appears in and c2 is
// identified by 1. So, we need to find the number of times
// each of these distinct values occur.
// Invariants:
// 1. At the beginning of the i-th iteration, the number of
// unique configurations seen so far is equal to the number of
// non-zero counter values in config[:i].
// 2. At the beginning of the i-th iteration, the sum of
// elements of configCounter[:i] is equal to the number of
// non-error configurations seen so far.
// For each of the serverConfig ...
for i := range serverConfigs {
// Skip nodes where getConfig failed.
if errs[i] != nil {
continue
}
// Check if it is equal to any of the configurations
// seen so far. If j == i is reached then we have an
// unseen configuration.
for j := 0; j <= i; j++ {
if j < i && configCounter[j] == 0 {
// serverConfigs[j] is known to be
// equal to a value that was already
// seen. See example above for
// clarity.
continue
} else if j < i && reflect.DeepEqual(serverConfigs[i], serverConfigs[j]) {
// serverConfigs[i] is equal to
// serverConfigs[j], update
// serverConfigs[j]'s counter since it
// is the lower index.
configCounter[j]++
break
} else if j == i {
// serverConfigs[i] is equal to no
// other value seen before. It is
// unique so far.
configCounter[i] = 1
break
} // else invariants specified above are violated.
}
}
// We find the maximally occurring server config and check if
// there is quorum.
var configJSON serverConfigV13
maxOccurrence := 0
for i, count := range configCounter {
if maxOccurrence < count {
maxOccurrence = count
configJSON = serverConfigs[i]
}
}
// If quorum nodes don't agree.
if maxOccurrence < quorum {
return scv, errXLWriteQuorum
}
return configJSON, nil
}
// Write config contents into a temporary file on all nodes.
func writeTmpConfigPeers(peers adminPeers, tmpFileName string, configBytes []byte) []error {
// For a single-node minio server setup.
if !globalIsDistXL {
err := peers[0].cmdRunner.WriteTmpConfig(tmpFileName, configBytes)
return []error{err}
}
errs := make([]error, len(peers))
// Write config into temporary file on all nodes.
wg := sync.WaitGroup{}
for i, peer := range peers {
wg.Add(1)
go func(idx int, peer adminPeer) {
defer wg.Done()
errs[idx] = peer.cmdRunner.WriteTmpConfig(tmpFileName, configBytes)
}(i, peer)
}
wg.Wait()
// Return bytes written and errors (if any) during writing
// temporary config file.
return errs
}
// Move config contents from the given temporary file onto config.json
// on all nodes.
func commitConfigPeers(peers adminPeers, tmpFileName string) []error {
// For a single-node minio server setup.
if !globalIsDistXL {
return []error{peers[0].cmdRunner.CommitConfig(tmpFileName)}
}
errs := make([]error, len(peers))
// Rename temporary config file into configDir/config.json on
// all nodes.
wg := sync.WaitGroup{}
for i, peer := range peers {
wg.Add(1)
go func(idx int, peer adminPeer) {
defer wg.Done()
errs[idx] = peer.cmdRunner.CommitConfig(tmpFileName)
}(i, peer)
}
wg.Wait()
// Return errors (if any) received during rename.
return errs
}