minio/cmd/admin-rpc-client.go
2018-08-06 10:26:40 -07:00

490 lines
13 KiB
Go

/*
* Minio Cloud Storage, (C) 2014, 2015, 2016, 2017, 2018 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 (
"context"
"crypto/tls"
"encoding/json"
"fmt"
"net"
"sort"
"strings"
"sync"
"time"
"github.com/minio/minio/cmd/logger"
xnet "github.com/minio/minio/pkg/net"
)
var errUnsupportedSignal = fmt.Errorf("unsupported signal: only restart and stop signals are supported")
// AdminRPCClient - admin RPC client talks to admin RPC server.
type AdminRPCClient struct {
*RPCClient
}
// SignalService - calls SignalService RPC.
func (rpcClient *AdminRPCClient) SignalService(signal serviceSignal) (err error) {
args := SignalServiceArgs{Sig: signal}
reply := VoidReply{}
return rpcClient.Call(adminServiceName+".SignalService", &args, &reply)
}
// ReInitFormat - re-initialize disk format, remotely.
func (rpcClient *AdminRPCClient) ReInitFormat(dryRun bool) error {
args := ReInitFormatArgs{DryRun: dryRun}
reply := VoidReply{}
return rpcClient.Call(adminServiceName+".ReInitFormat", &args, &reply)
}
// ServerInfo - returns the server info of the server to which the RPC call is made.
func (rpcClient *AdminRPCClient) ServerInfo() (sid ServerInfoData, err error) {
err = rpcClient.Call(adminServiceName+".ServerInfo", &AuthArgs{}, &sid)
return sid, err
}
// GetConfig - returns config.json of the remote server.
func (rpcClient *AdminRPCClient) GetConfig() ([]byte, error) {
args := AuthArgs{}
var reply []byte
err := rpcClient.Call(adminServiceName+".GetConfig", &args, &reply)
return reply, err
}
// WriteTmpConfig - writes config file content to a temporary file on a remote node.
func (rpcClient *AdminRPCClient) WriteTmpConfig(tmpFileName string, configBytes []byte) error {
args := WriteConfigArgs{
TmpFileName: tmpFileName,
Buf: configBytes,
}
reply := VoidReply{}
err := rpcClient.Call(adminServiceName+".WriteTmpConfig", &args, &reply)
logger.LogIf(context.Background(), err)
return err
}
// CommitConfig - Move the new config in tmpFileName onto config.json on a remote node.
func (rpcClient *AdminRPCClient) CommitConfig(tmpFileName string) error {
args := CommitConfigArgs{FileName: tmpFileName}
reply := VoidReply{}
err := rpcClient.Call(adminServiceName+".CommitConfig", &args, &reply)
logger.LogIf(context.Background(), err)
return err
}
// NewAdminRPCClient - returns new admin RPC client.
func NewAdminRPCClient(host *xnet.Host) (*AdminRPCClient, error) {
scheme := "http"
if globalIsSSL {
scheme = "https"
}
serviceURL := &xnet.URL{
Scheme: scheme,
Host: host.String(),
Path: adminServicePath,
}
var tlsConfig *tls.Config
if globalIsSSL {
tlsConfig = &tls.Config{
ServerName: host.Name,
RootCAs: globalRootCAs,
}
}
rpcClient, err := NewRPCClient(
RPCClientArgs{
NewAuthTokenFunc: newAuthToken,
RPCVersion: globalRPCAPIVersion,
ServiceName: adminServiceName,
ServiceURL: serviceURL,
TLSConfig: tlsConfig,
},
)
if err != nil {
return nil, err
}
return &AdminRPCClient{rpcClient}, nil
}
// adminCmdRunner - abstracts local and remote execution of admin
// commands like service stop and service restart.
type adminCmdRunner interface {
SignalService(s serviceSignal) error
ReInitFormat(dryRun bool) error
ServerInfo() (ServerInfoData, error)
GetConfig() ([]byte, error)
WriteTmpConfig(tmpFileName string, configBytes []byte) error
CommitConfig(tmpFileName string) error
}
// adminPeer - represents an entity that implements admin API RPCs.
type adminPeer struct {
addr string
cmdRunner adminCmdRunner
isLocal bool
}
// 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) {
localAddr := GetLocalPeer(endpoints)
if strings.HasPrefix(localAddr, "127.0.0.1:") {
// Use first IPv4 instead of loopback address.
localAddr = net.JoinHostPort(sortIPs(localIP4.ToSlice())[0], globalMinioPort)
}
adminPeerList = append(adminPeerList, adminPeer{
addr: localAddr,
cmdRunner: localAdminClient{},
isLocal: true,
})
for _, hostStr := range GetRemotePeers(endpoints) {
host, err := xnet.ParseHost(hostStr)
logger.FatalIf(err, "Unable to parse Admin RPC Host", context.Background())
rpcClient, err := NewAdminRPCClient(host)
logger.FatalIf(err, "Unable to initialize Admin RPC Client", context.Background())
adminPeerList = append(adminPeerList, adminPeer{
addr: hostStr,
cmdRunner: rpcClient,
})
}
return adminPeerList
}
// peersReInitFormat - reinitialize remote object layers to new format.
func peersReInitFormat(peers adminPeers, dryRun bool) error {
errs := make([]error, len(peers))
// Send ReInitFormat 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()
if !peer.isLocal {
errs[idx] = peer.cmdRunner.ReInitFormat(dryRun)
}
}(i, peer)
}
wg.Wait()
return nil
}
// Initialize global adminPeer collection.
func initGlobalAdminPeers(endpoints EndpointList) {
globalAdminPeers = makeAdminPeers(endpoints)
}
// invokeServiceCmd - Invoke Restart/Stop command.
func invokeServiceCmd(cp adminPeer, cmd serviceSignal) (err error) {
switch cmd {
case serviceRestart, serviceStop:
err = cp.cmdRunner.SignalService(cmd)
}
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)
}
// 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.ServerInfo()
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 {
logger.LogIf(context.Background(), uptime.err)
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([]serverConfig, 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 {
reqInfo := (&logger.ReqInfo{}).AppendTags("peerAddress", peers[i].addr)
ctx := logger.SetReqInfo(context.Background(), reqInfo)
logger.LogIf(ctx, err)
return nil, err
}
}
configJSON, err := getValidServerConfig(serverConfigs, errs)
if err != nil {
logger.LogIf(context.Background(), err)
return nil, 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 []serverConfig, errs []error) (scv serverConfig, 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
}
if j < i && serverConfigs[i].ConfigDiff(&serverConfigs[j]) == "" {
// serverConfigs[i] is equal to
// serverConfigs[j], update
// serverConfigs[j]'s counter since it
// is the lower index.
configCounter[j]++
break
}
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 serverConfig
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
}