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moby--moby/libnetwork/networkdb/networkdb.go
Flavio Crisciani 3e544bc500 Avoid extra notification on node leave
If a node leave, avoid to notify the upper layer
for entries that are already marked for deletion

Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
2017-12-01 16:19:38 -08:00

759 lines
23 KiB
Go

package networkdb
//go:generate protoc -I.:../vendor/github.com/gogo/protobuf --gogo_out=import_path=github.com/docker/libnetwork/networkdb,Mgogoproto/gogo.proto=github.com/gogo/protobuf/gogoproto:. networkdb.proto
import (
"fmt"
"net"
"os"
"strings"
"sync"
"time"
"github.com/armon/go-radix"
"github.com/docker/docker/pkg/stringid"
"github.com/docker/go-events"
"github.com/docker/libnetwork/types"
"github.com/hashicorp/memberlist"
"github.com/hashicorp/serf/serf"
"github.com/sirupsen/logrus"
)
const (
byTable int = 1 + iota
byNetwork
)
// NetworkDB instance drives the networkdb cluster and acts the broker
// for cluster-scoped and network-scoped gossip and watches.
type NetworkDB struct {
// The clocks MUST be the first things
// in this struct due to Golang issue #599.
// Global lamport clock for node network attach events.
networkClock serf.LamportClock
// Global lamport clock for table events.
tableClock serf.LamportClock
sync.RWMutex
// NetworkDB configuration.
config *Config
// All the tree index (byTable, byNetwork) that we maintain
// the db.
indexes map[int]*radix.Tree
// Memberlist we use to drive the cluster.
memberlist *memberlist.Memberlist
// List of all peer nodes in the cluster not-limited to any
// network.
nodes map[string]*node
// List of all peer nodes which have failed
failedNodes map[string]*node
// List of all peer nodes which have left
leftNodes map[string]*node
// A multi-dimensional map of network/node attachmemts. The
// first key is a node name and the second key is a network ID
// for the network that node is participating in.
networks map[string]map[string]*network
// A map of nodes which are participating in a given
// network. The key is a network ID.
networkNodes map[string][]string
// A table of ack channels for every node from which we are
// waiting for an ack.
bulkSyncAckTbl map[string]chan struct{}
// Broadcast queue for network event gossip.
networkBroadcasts *memberlist.TransmitLimitedQueue
// Broadcast queue for node event gossip.
nodeBroadcasts *memberlist.TransmitLimitedQueue
// A central stop channel to stop all go routines running on
// behalf of the NetworkDB instance.
stopCh chan struct{}
// A central broadcaster for all local watchers watching table
// events.
broadcaster *events.Broadcaster
// List of all tickers which needed to be stopped when
// cleaning up.
tickers []*time.Ticker
// Reference to the memberlist's keyring to add & remove keys
keyring *memberlist.Keyring
// bootStrapIP is the list of IPs that can be used to bootstrap
// the gossip.
bootStrapIP []net.IP
// lastStatsTimestamp is the last timestamp when the stats got printed
lastStatsTimestamp time.Time
// lastHealthTimestamp is the last timestamp when the health score got printed
lastHealthTimestamp time.Time
}
// PeerInfo represents the peer (gossip cluster) nodes of a network
type PeerInfo struct {
Name string
IP string
}
// PeerClusterInfo represents the peer (gossip cluster) nodes
type PeerClusterInfo struct {
PeerInfo
}
type node struct {
memberlist.Node
ltime serf.LamportTime
// Number of hours left before the reaper removes the node
reapTime time.Duration
}
// network describes the node/network attachment.
type network struct {
// Network ID
id string
// Lamport time for the latest state of the entry.
ltime serf.LamportTime
// Node leave is in progress.
leaving bool
// Number of seconds still left before a deleted network entry gets
// removed from networkDB
reapTime time.Duration
// The broadcast queue for table event gossip. This is only
// initialized for this node's network attachment entries.
tableBroadcasts *memberlist.TransmitLimitedQueue
// Number of gossip messages sent related to this network during the last stats collection period
qMessagesSent int
// Number of entries on the network. This value is the sum of all the entries of all the tables of a specific network.
// Its use is for statistics purposes. It keep tracks of database size and is printed per network every StatsPrintPeriod
// interval
entriesNumber int
}
// Config represents the configuration of the networdb instance and
// can be passed by the caller.
type Config struct {
// NodeID is the node unique identifier of the node when is part of the cluster
NodeID string
// Hostname is the node hostname.
Hostname string
// BindAddr is the IP on which networkdb listens. It can be
// 0.0.0.0 to listen on all addresses on the host.
BindAddr string
// AdvertiseAddr is the node's IP address that we advertise for
// cluster communication.
AdvertiseAddr string
// BindPort is the local node's port to which we bind to for
// cluster communication.
BindPort int
// Keys to be added to the Keyring of the memberlist. Key at index
// 0 is the primary key
Keys [][]byte
// PacketBufferSize is the maximum number of bytes that memberlist will
// put in a packet (this will be for UDP packets by default with a NetTransport).
// A safe value for this is typically 1400 bytes (which is the default). However,
// depending on your network's MTU (Maximum Transmission Unit) you may
// be able to increase this to get more content into each gossip packet.
PacketBufferSize int
// reapEntryInterval duration of a deleted entry before being garbage collected
reapEntryInterval time.Duration
// reapNetworkInterval duration of a delted network before being garbage collected
// NOTE this MUST always be higher than reapEntryInterval
reapNetworkInterval time.Duration
// StatsPrintPeriod the period to use to print queue stats
// Default is 5min
StatsPrintPeriod time.Duration
// HealthPrintPeriod the period to use to print the health score
// Default is 1min
HealthPrintPeriod time.Duration
}
// entry defines a table entry
type entry struct {
// node from which this entry was learned.
node string
// Lamport time for the most recent update to the entry
ltime serf.LamportTime
// Opaque value store in the entry
value []byte
// Deleting the entry is in progress. All entries linger in
// the cluster for certain amount of time after deletion.
deleting bool
// Number of seconds still left before a deleted table entry gets
// removed from networkDB
reapTime time.Duration
}
// DefaultConfig returns a NetworkDB config with default values
func DefaultConfig() *Config {
hostname, _ := os.Hostname()
return &Config{
NodeID: stringid.TruncateID(stringid.GenerateRandomID()),
Hostname: hostname,
BindAddr: "0.0.0.0",
PacketBufferSize: 1400,
StatsPrintPeriod: 5 * time.Minute,
HealthPrintPeriod: 1 * time.Minute,
reapEntryInterval: 30 * time.Minute,
}
}
// New creates a new instance of NetworkDB using the Config passed by
// the caller.
func New(c *Config) (*NetworkDB, error) {
// The garbage collection logic for entries leverage the presence of the network.
// For this reason the expiration time of the network is put slightly higher than the entry expiration so that
// there is at least 5 extra cycle to make sure that all the entries are properly deleted before deleting the network.
c.reapNetworkInterval = c.reapEntryInterval + 5*reapPeriod
nDB := &NetworkDB{
config: c,
indexes: make(map[int]*radix.Tree),
networks: make(map[string]map[string]*network),
nodes: make(map[string]*node),
failedNodes: make(map[string]*node),
leftNodes: make(map[string]*node),
networkNodes: make(map[string][]string),
bulkSyncAckTbl: make(map[string]chan struct{}),
broadcaster: events.NewBroadcaster(),
}
nDB.indexes[byTable] = radix.New()
nDB.indexes[byNetwork] = radix.New()
logrus.Infof("New memberlist node - Node:%v will use memberlist nodeID:%v with config:%+v", c.Hostname, c.NodeID, c)
if err := nDB.clusterInit(); err != nil {
return nil, err
}
return nDB, nil
}
// Join joins this NetworkDB instance with a list of peer NetworkDB
// instances passed by the caller in the form of addr:port
func (nDB *NetworkDB) Join(members []string) error {
nDB.Lock()
nDB.bootStrapIP = make([]net.IP, 0, len(members))
for _, m := range members {
nDB.bootStrapIP = append(nDB.bootStrapIP, net.ParseIP(m))
}
nDB.Unlock()
return nDB.clusterJoin(members)
}
// Close destroys this NetworkDB instance by leave the cluster,
// stopping timers, canceling goroutines etc.
func (nDB *NetworkDB) Close() {
if err := nDB.clusterLeave(); err != nil {
logrus.Errorf("%v(%v) Could not close DB: %v", nDB.config.Hostname, nDB.config.NodeID, err)
}
//Avoid (*Broadcaster).run goroutine leak
nDB.broadcaster.Close()
}
// ClusterPeers returns all the gossip cluster peers.
func (nDB *NetworkDB) ClusterPeers() []PeerInfo {
nDB.RLock()
defer nDB.RUnlock()
peers := make([]PeerInfo, 0, len(nDB.nodes))
for _, node := range nDB.nodes {
peers = append(peers, PeerInfo{
Name: node.Name,
IP: node.Node.Addr.String(),
})
}
return peers
}
// Peers returns the gossip peers for a given network.
func (nDB *NetworkDB) Peers(nid string) []PeerInfo {
nDB.RLock()
defer nDB.RUnlock()
peers := make([]PeerInfo, 0, len(nDB.networkNodes[nid]))
for _, nodeName := range nDB.networkNodes[nid] {
if node, ok := nDB.nodes[nodeName]; ok {
peers = append(peers, PeerInfo{
Name: node.Name,
IP: node.Addr.String(),
})
} else {
// Added for testing purposes, this condition should never happen else mean that the network list
// is out of sync with the node list
peers = append(peers, PeerInfo{})
}
}
return peers
}
// GetEntry retrieves the value of a table entry in a given (network,
// table, key) tuple
func (nDB *NetworkDB) GetEntry(tname, nid, key string) ([]byte, error) {
entry, err := nDB.getEntry(tname, nid, key)
if err != nil {
return nil, err
}
return entry.value, nil
}
func (nDB *NetworkDB) getEntry(tname, nid, key string) (*entry, error) {
nDB.RLock()
defer nDB.RUnlock()
e, ok := nDB.indexes[byTable].Get(fmt.Sprintf("/%s/%s/%s", tname, nid, key))
if !ok {
return nil, types.NotFoundErrorf("could not get entry in table %s with network id %s and key %s", tname, nid, key)
}
return e.(*entry), nil
}
// CreateEntry creates a table entry in NetworkDB for given (network,
// table, key) tuple and if the NetworkDB is part of the cluster
// propagates this event to the cluster. It is an error to create an
// entry for the same tuple for which there is already an existing
// entry unless the current entry is deleting state.
func (nDB *NetworkDB) CreateEntry(tname, nid, key string, value []byte) error {
oldEntry, err := nDB.getEntry(tname, nid, key)
if err != nil {
if _, ok := err.(types.NotFoundError); !ok {
return fmt.Errorf("cannot create entry in table %s with network id %s and key %s: %v", tname, nid, key, err)
}
}
if oldEntry != nil && !oldEntry.deleting {
return fmt.Errorf("cannot create entry in table %s with network id %s and key %s, already exists", tname, nid, key)
}
entry := &entry{
ltime: nDB.tableClock.Increment(),
node: nDB.config.NodeID,
value: value,
}
if err := nDB.sendTableEvent(TableEventTypeCreate, nid, tname, key, entry); err != nil {
return fmt.Errorf("cannot send create event for table %s, %v", tname, err)
}
nDB.Lock()
nDB.createOrUpdateEntry(nid, tname, key, entry)
nDB.Unlock()
return nil
}
// UpdateEntry updates a table entry in NetworkDB for given (network,
// table, key) tuple and if the NetworkDB is part of the cluster
// propagates this event to the cluster. It is an error to update a
// non-existent entry.
func (nDB *NetworkDB) UpdateEntry(tname, nid, key string, value []byte) error {
if _, err := nDB.GetEntry(tname, nid, key); err != nil {
return fmt.Errorf("cannot update entry as the entry in table %s with network id %s and key %s does not exist", tname, nid, key)
}
entry := &entry{
ltime: nDB.tableClock.Increment(),
node: nDB.config.NodeID,
value: value,
}
if err := nDB.sendTableEvent(TableEventTypeUpdate, nid, tname, key, entry); err != nil {
return fmt.Errorf("cannot send table update event: %v", err)
}
nDB.Lock()
nDB.createOrUpdateEntry(nid, tname, key, entry)
nDB.Unlock()
return nil
}
// TableElem elem
type TableElem struct {
Value []byte
owner string
}
// GetTableByNetwork walks the networkdb by the give table and network id and
// returns a map of keys and values
func (nDB *NetworkDB) GetTableByNetwork(tname, nid string) map[string]*TableElem {
entries := make(map[string]*TableElem)
nDB.indexes[byTable].WalkPrefix(fmt.Sprintf("/%s/%s", tname, nid), func(k string, v interface{}) bool {
entry := v.(*entry)
if entry.deleting {
return false
}
key := k[strings.LastIndex(k, "/")+1:]
entries[key] = &TableElem{Value: entry.value, owner: entry.node}
return false
})
return entries
}
// DeleteEntry deletes a table entry in NetworkDB for given (network,
// table, key) tuple and if the NetworkDB is part of the cluster
// propagates this event to the cluster.
func (nDB *NetworkDB) DeleteEntry(tname, nid, key string) error {
value, err := nDB.GetEntry(tname, nid, key)
if err != nil {
return fmt.Errorf("cannot delete entry as the entry in table %s with network id %s and key %s does not exist", tname, nid, key)
}
entry := &entry{
ltime: nDB.tableClock.Increment(),
node: nDB.config.NodeID,
value: value,
deleting: true,
reapTime: nDB.config.reapEntryInterval,
}
if err := nDB.sendTableEvent(TableEventTypeDelete, nid, tname, key, entry); err != nil {
return fmt.Errorf("cannot send table delete event: %v", err)
}
nDB.Lock()
nDB.createOrUpdateEntry(nid, tname, key, entry)
nDB.Unlock()
return nil
}
func (nDB *NetworkDB) deleteNodeFromNetworks(deletedNode string) {
for nid, nodes := range nDB.networkNodes {
updatedNodes := make([]string, 0, len(nodes))
for _, node := range nodes {
if node == deletedNode {
continue
}
updatedNodes = append(updatedNodes, node)
}
nDB.networkNodes[nid] = updatedNodes
}
delete(nDB.networks, deletedNode)
}
// deleteNodeNetworkEntries is called in 2 conditions with 2 different outcomes:
// 1) when a notification is coming of a node leaving the network
// - Walk all the network entries and mark the leaving node's entries for deletion
// These will be garbage collected when the reap timer will expire
// 2) when the local node is leaving the network
// - Walk all the network entries:
// A) if the entry is owned by the local node
// then we will mark it for deletion. This will ensure that if a node did not
// yet received the notification that the local node is leaving, will be aware
// of the entries to be deleted.
// B) if the entry is owned by a remote node, then we can safely delete it. This
// ensures that if we join back this network as we receive the CREATE event for
// entries owned by remote nodes, we will accept them and we notify the application
func (nDB *NetworkDB) deleteNodeNetworkEntries(nid, node string) {
// Indicates if the delete is triggered for the local node
isNodeLocal := node == nDB.config.NodeID
nDB.indexes[byNetwork].WalkPrefix(fmt.Sprintf("/%s", nid),
func(path string, v interface{}) bool {
oldEntry := v.(*entry)
params := strings.Split(path[1:], "/")
nid := params[0]
tname := params[1]
key := params[2]
// If the entry is owned by a remote node and this node is not leaving the network
if oldEntry.node != node && !isNodeLocal {
// Don't do anything because the event is triggered for a node that does not own this entry
return false
}
// If this entry is already marked for deletion and this node is not leaving the network
if oldEntry.deleting && !isNodeLocal {
// Don't do anything this entry will be already garbage collected using the old reapTime
return false
}
entry := &entry{
ltime: oldEntry.ltime,
node: oldEntry.node,
value: oldEntry.value,
deleting: true,
reapTime: nDB.config.reapEntryInterval,
}
// we arrived at this point in 2 cases:
// 1) this entry is owned by the node that is leaving the network
// 2) the local node is leaving the network
if oldEntry.node == node {
if isNodeLocal {
// TODO fcrisciani: this can be removed if there is no way to leave the network
// without doing a delete of all the objects
entry.ltime++
}
if !oldEntry.deleting {
nDB.createOrUpdateEntry(nid, tname, key, entry)
}
} else {
// the local node is leaving the network, all the entries of remote nodes can be safely removed
nDB.deleteEntry(nid, tname, key)
}
// Notify to the upper layer only entries not already marked for deletion
if !oldEntry.deleting {
nDB.broadcaster.Write(makeEvent(opDelete, tname, nid, key, entry.value))
}
return false
})
}
func (nDB *NetworkDB) deleteNodeTableEntries(node string) {
nDB.indexes[byTable].Walk(func(path string, v interface{}) bool {
oldEntry := v.(*entry)
if oldEntry.node != node {
return false
}
params := strings.Split(path[1:], "/")
tname := params[0]
nid := params[1]
key := params[2]
nDB.deleteEntry(nid, tname, key)
if !oldEntry.deleting {
nDB.broadcaster.Write(makeEvent(opDelete, tname, nid, key, oldEntry.value))
}
return false
})
}
// WalkTable walks a single table in NetworkDB and invokes the passed
// function for each entry in the table passing the network, key,
// value. The walk stops if the passed function returns a true.
func (nDB *NetworkDB) WalkTable(tname string, fn func(string, string, []byte, bool) bool) error {
nDB.RLock()
values := make(map[string]interface{})
nDB.indexes[byTable].WalkPrefix(fmt.Sprintf("/%s", tname), func(path string, v interface{}) bool {
values[path] = v
return false
})
nDB.RUnlock()
for k, v := range values {
params := strings.Split(k[1:], "/")
nid := params[1]
key := params[2]
if fn(nid, key, v.(*entry).value, v.(*entry).deleting) {
return nil
}
}
return nil
}
// JoinNetwork joins this node to a given network and propagates this
// event across the cluster. This triggers this node joining the
// sub-cluster of this network and participates in the network-scoped
// gossip and bulk sync for this network.
func (nDB *NetworkDB) JoinNetwork(nid string) error {
ltime := nDB.networkClock.Increment()
nDB.Lock()
nodeNetworks, ok := nDB.networks[nDB.config.NodeID]
if !ok {
nodeNetworks = make(map[string]*network)
nDB.networks[nDB.config.NodeID] = nodeNetworks
}
n, ok := nodeNetworks[nid]
var entries int
if ok {
entries = n.entriesNumber
}
nodeNetworks[nid] = &network{id: nid, ltime: ltime, entriesNumber: entries}
nodeNetworks[nid].tableBroadcasts = &memberlist.TransmitLimitedQueue{
NumNodes: func() int {
//TODO fcrisciani this can be optimized maybe avoiding the lock?
// this call is done each GetBroadcasts call to evaluate the number of
// replicas for the message
nDB.RLock()
defer nDB.RUnlock()
return len(nDB.networkNodes[nid])
},
RetransmitMult: 4,
}
nDB.addNetworkNode(nid, nDB.config.NodeID)
networkNodes := nDB.networkNodes[nid]
nDB.Unlock()
if err := nDB.sendNetworkEvent(nid, NetworkEventTypeJoin, ltime); err != nil {
return fmt.Errorf("failed to send leave network event for %s: %v", nid, err)
}
logrus.Debugf("%v(%v): joined network %s", nDB.config.Hostname, nDB.config.NodeID, nid)
if _, err := nDB.bulkSync(networkNodes, true); err != nil {
logrus.Errorf("Error bulk syncing while joining network %s: %v", nid, err)
}
return nil
}
// LeaveNetwork leaves this node from a given network and propagates
// this event across the cluster. This triggers this node leaving the
// sub-cluster of this network and as a result will no longer
// participate in the network-scoped gossip and bulk sync for this
// network. Also remove all the table entries for this network from
// networkdb
func (nDB *NetworkDB) LeaveNetwork(nid string) error {
ltime := nDB.networkClock.Increment()
if err := nDB.sendNetworkEvent(nid, NetworkEventTypeLeave, ltime); err != nil {
return fmt.Errorf("failed to send leave network event for %s: %v", nid, err)
}
nDB.Lock()
defer nDB.Unlock()
// Remove myself from the list of the nodes participating to the network
nDB.deleteNetworkNode(nid, nDB.config.NodeID)
// Update all the local entries marking them for deletion and delete all the remote entries
nDB.deleteNodeNetworkEntries(nid, nDB.config.NodeID)
nodeNetworks, ok := nDB.networks[nDB.config.NodeID]
if !ok {
return fmt.Errorf("could not find self node for network %s while trying to leave", nid)
}
n, ok := nodeNetworks[nid]
if !ok {
return fmt.Errorf("could not find network %s while trying to leave", nid)
}
logrus.Debugf("%v(%v): leaving network %s", nDB.config.Hostname, nDB.config.NodeID, nid)
n.ltime = ltime
n.reapTime = nDB.config.reapNetworkInterval
n.leaving = true
return nil
}
// addNetworkNode adds the node to the list of nodes which participate
// in the passed network only if it is not already present. Caller
// should hold the NetworkDB lock while calling this
func (nDB *NetworkDB) addNetworkNode(nid string, nodeName string) {
nodes := nDB.networkNodes[nid]
for _, node := range nodes {
if node == nodeName {
return
}
}
nDB.networkNodes[nid] = append(nDB.networkNodes[nid], nodeName)
}
// Deletes the node from the list of nodes which participate in the
// passed network. Caller should hold the NetworkDB lock while calling
// this
func (nDB *NetworkDB) deleteNetworkNode(nid string, nodeName string) {
nodes, ok := nDB.networkNodes[nid]
if !ok || len(nodes) == 0 {
return
}
newNodes := make([]string, 0, len(nodes)-1)
for _, name := range nodes {
if name == nodeName {
continue
}
newNodes = append(newNodes, name)
}
nDB.networkNodes[nid] = newNodes
}
// findCommonnetworks find the networks that both this node and the
// passed node have joined.
func (nDB *NetworkDB) findCommonNetworks(nodeName string) []string {
nDB.RLock()
defer nDB.RUnlock()
var networks []string
for nid := range nDB.networks[nDB.config.NodeID] {
if n, ok := nDB.networks[nodeName][nid]; ok {
if !n.leaving {
networks = append(networks, nid)
}
}
}
return networks
}
func (nDB *NetworkDB) updateLocalNetworkTime() {
nDB.Lock()
defer nDB.Unlock()
ltime := nDB.networkClock.Increment()
for _, n := range nDB.networks[nDB.config.NodeID] {
n.ltime = ltime
}
}
// createOrUpdateEntry this function handles the creation or update of entries into the local
// tree store. It is also used to keep in sync the entries number of the network (all tables are aggregated)
func (nDB *NetworkDB) createOrUpdateEntry(nid, tname, key string, entry interface{}) (bool, bool) {
_, okTable := nDB.indexes[byTable].Insert(fmt.Sprintf("/%s/%s/%s", tname, nid, key), entry)
_, okNetwork := nDB.indexes[byNetwork].Insert(fmt.Sprintf("/%s/%s/%s", nid, tname, key), entry)
if !okNetwork {
// Add only if it is an insert not an update
n, ok := nDB.networks[nDB.config.NodeID][nid]
if ok {
n.entriesNumber++
}
}
return okTable, okNetwork
}
// deleteEntry this function handles the deletion of entries into the local tree store.
// It is also used to keep in sync the entries number of the network (all tables are aggregated)
func (nDB *NetworkDB) deleteEntry(nid, tname, key string) (bool, bool) {
_, okTable := nDB.indexes[byTable].Delete(fmt.Sprintf("/%s/%s/%s", tname, nid, key))
_, okNetwork := nDB.indexes[byNetwork].Delete(fmt.Sprintf("/%s/%s/%s", nid, tname, key))
if okNetwork {
// Remove only if the delete is successful
n, ok := nDB.networks[nDB.config.NodeID][nid]
if ok {
n.entriesNumber--
}
}
return okTable, okNetwork
}