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Building blocks for ClusterMate-based services and servers.
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package com.fasterxml.clustermate.service.cluster;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.atomic.AtomicLong;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.fasterxml.storemate.shared.IpAndPort;
import com.fasterxml.storemate.shared.TimeMaster;
import com.fasterxml.storemate.store.state.NodeStateStore;
import com.fasterxml.clustermate.api.*;
import com.fasterxml.clustermate.api.msg.ClusterStatusMessage;
import com.fasterxml.clustermate.json.ClusterMessageConverter;
import com.fasterxml.clustermate.service.ServiceResponse;
import com.fasterxml.clustermate.service.SharedServiceStuff;
import com.fasterxml.clustermate.service.Stores;
import com.fasterxml.clustermate.service.cfg.ServiceConfig;
import com.fasterxml.clustermate.service.remote.RemoteCluster;
import com.fasterxml.clustermate.service.remote.RemoteClusterHandler;
import com.fasterxml.clustermate.service.state.ActiveNodeState;
import com.fasterxml.clustermate.service.store.StoredEntry;
import com.fasterxml.clustermate.std.JdkClusterStatusAccessor;
public class ClusterViewByServerImpl>
extends ClusterViewByServerUpdatable
{
private final Logger LOG = LoggerFactory.getLogger(getClass());
protected final SharedServiceStuff _stuff;
/**
* Key space used by this cluster.
*/
protected final KeySpace _keyspace;
protected final Stores _stores;
/**
* Information about this node; not included in the list of peer nodes.
*/
protected final NodeState _localState;
/**
* States of all nodes found during bootstrapping, including the
* local node.
*/
protected final Map> _peers;
protected final TimeMaster _timeMaster;
protected final ClusterStatusAccessor _clusterAccessor;
/**
* Need a reference to remote-peer handler just to return remote-peer
* info for status requests.
*/
protected RemoteClusterHandler _remoteClusterHandler;
/**
* Timestamp of the last update to aggregated state; used for letting
* clients know whether to try to access updated cluster information
*/
protected final AtomicLong _lastUpdated;
protected final boolean _isTesting;
/*
/**********************************************************************
/* Life-cycle
/**********************************************************************
*/
public ClusterViewByServerImpl(SharedServiceStuff stuff, Stores stores,
KeySpace keyspace,
ActiveNodeState local, Map remoteNodes,
long updateTime)
{
_stuff = stuff;
_localState = local;
_keyspace = keyspace;
_stores = stores;
_timeMaster = stuff.getTimeMaster();
_isTesting = stuff.isRunningTests();
ServiceConfig config = stuff.getServiceConfig();
_clusterAccessor = new JdkClusterStatusAccessor(new ClusterMessageConverter(
stuff.jsonMapper()),
config.servicePathRoot, config.getServicePathStrategy());
_peers = new LinkedHashMap>(remoteNodes.size());
for (Map.Entry entry : remoteNodes.entrySet()) {
_peers.put(entry.getKey(), _createPeer(entry.getValue()));
}
_lastUpdated = new AtomicLong(updateTime);
}
public void setRemoteHandler(RemoteClusterHandler h) {
_remoteClusterHandler = h;
}
private ClusterPeerImpl _createPeer(ActiveNodeState nodeState) {
return new ClusterPeerImpl(_stuff, this,
_stores.getNodeStore(), _stores.getEntryStore(), nodeState,
_clusterAccessor);
}
@Override
public synchronized void start()
{
LOG.info("Starting sync threads to peers...");
int count = 0;
// no need to sync yet
for (final ClusterPeerImpl peer : _peers.values()) {
/* 20-Nov-2012, tatu: Let's create a thread for every peer from now
* on; even if there is currently no sync range, things may change.
* Plus, for fast cluster view updates, may want to share info
* between non-neighbors too.
*/
++count;
peer.startSyncing();
}
LOG.info("Completed creation of sync threads ({}/{}) to peers", count, _peers.size());
}
@Override
public synchronized void prepareForStop() {
LOG.info("Pre-shutdown notice to stop active synchronization requests");
for (ClusterPeerImpl peer : _peers.values()) {
peer.prepareForStop();
}
LOG.info("Completed pre-shutdown notices for synchronization");
}
@Override
public synchronized void stop()
{
LOG.info("Shutting down sync threads to peers...");
for (ClusterPeerImpl peer : _peers.values()) {
peer.stop();
}
LOG.info("Completed shutting down sync threads to peers");
}
/*
/**********************************************************************
/* Simple accessors
/**********************************************************************
*/
/**
* Returns size of cluster, which should be one greater than number of
* peer nodes (to add local node)
*/
@Override
public int size() { return 1 + _peers.size(); }
@Override
public KeySpace getKeySpace() { return _keyspace; }
@Override
public NodeState getLocalState() { return _localState; }
@Override
public NodeState getRemoteState(IpAndPort key) {
ClusterPeerImpl peer;
synchronized (_peers) {
peer = _peers.get(key);
}
return (peer == null) ? null : peer.getSyncState();
}
@Override
public List getPeers() {
synchronized (_peers) {
return new ArrayList(_peers.values());
}
}
@Override
public Collection getPeerStates() {
ArrayList result = new ArrayList(_peers.size());
for (ClusterPeerImpl peer : _peers.values()) {
result.add(peer.getSyncState());
}
return result;
}
@Override
public long getLastUpdated() {
return _lastUpdated.get();
}
@Override
public boolean containsLocally(EntryKey key)
{
int hash = _stuff.getKeyConverter().routingHashFor(key);
return _localState.totalRange().contains(hash);
}
/*
/**********************************************************************
/* NodeStatusUpdater impl
/**********************************************************************
*/
@Override
public void nodeActivated(IpAndPort endpoint, long timestamp, KeyRange totalRange)
{
// for now, no real difference so:
checkMembership(endpoint, timestamp, totalRange);
}
@Override
public void nodeDeactivated(IpAndPort endpoint, long timestamp)
{
// First, a sanity check:
if (_localState.getAddress().equals(endpoint)) { // just sanity check
LOG.warn("checkMembership() called with local node address; ignoring");
return;
}
ClusterPeerImpl peer;
synchronized (_peers) {
peer = _peers.get(endpoint);
if (peer != null) {
peer.markDisabled(timestamp, true);
}
}
if (peer == null) {
LOG.warn("Unknown node {} reported being deactivated; ignoring", endpoint);
} else {
LOG.warn("Node {} reported being deactivated: marked as such", endpoint);
}
}
@Override
public void checkMembership(IpAndPort endpoint, long timestamp, KeyRange totalRange)
{
// First, a sanity check:
if (_localState.getAddress().equals(endpoint)) {
LOG.warn("checkMembership() called with local node address; ignoring");
return;
}
try {
synchronized (_peers) {
ClusterPeerImpl peer = _peers.get(endpoint);
if (peer != null) { // already known...
if (peer.isDisabled()) { // but do we enable it?
peer.markDisabled(timestamp, false);
LOG.info("Node {} activated due to received request", endpoint);
}
return;
}
/* How interesting! Someone who we don't even know seems to be joining...
* Two possible cases, then; (a) We are seeing something for which we do
* have data in local DB, just not in config file, or (b) New entry for
* which no data exists.
*/
ActiveNodeState oldState = _stores.getNodeStore().findEntry(endpoint);
// If such data found, assume it's accurate; we'll be updated soon if not
if (oldState != null) {
peer = _createPeer(oldState);
LOG.warn("Request from node {} for which we have info in Local DB, restoring", endpoint);
} else {
// But if not found need minimal bootstrapping
ActiveNodeState initialStatus = new ActiveNodeState(_localState,
new NodeDefinition(endpoint, NodeDefinition.INDEX_UNKNOWN,
totalRange, totalRange),
_timeMaster.currentTimeMillis());
peer = _createPeer(initialStatus);
LOG.warn("Request from node {} for which we have no information, bootstrap with range of {}",
endpoint, totalRange);
}
_peers.put(endpoint, peer);
peer.startSyncing();
/* No need to update local DB, since we really have little new information;
* should be getting it via sync-list by this node, or from other peers,
* depending on whether we are neighbors or not.
*/
}
} catch (IOException e) {
LOG.warn("Failed to update Node status for "+endpoint+": "+e.getMessage(), e);
}
}
/**
* Method called with a response to node status request; will update
* information we have if more recent information is available.
*/
@Override
public void updateWith(ClusterStatusMessage msg)
{
final long updateTime = _timeMaster.currentTimeMillis();
int mods = 0;
NodeState local = msg.local;
if (local == null) { // should never occur
LOG.info("msg.local is null, should never happen");
} else {
if (updateStatus(local, true)) {
++mods;
}
}
if (msg.localPeers != null) {
for (NodeState state : msg.localPeers) {
if (updateStatus(state, false)) {
++mods;
}
}
}
// If any data was changed, update our local state
if (mods > 0) {
boolean wasChanged;
synchronized (_lastUpdated) {
long old = _lastUpdated.get();
wasChanged = (updateTime > old);
if (wasChanged) {
_lastUpdated.set(updateTime);
}
}
if (wasChanged) {
LOG.info("updateStatus() with {} changes: updated lastUpdated to: {}", mods, updateTime);
} else { // may occur with concurrent updates?
LOG.warn("updateStatus() with {} changes: but lastUpdated remains at {}", mods,
_lastUpdated.get());
}
}
}
/**
* Method called for each node status entry in cluster status information message.
*
* @param nodeStatus Status to use for updating node state.
* @param byNodeItself True if the status is from the node itself; true for 'local'
* entry in status message.
*
* @return True if there was a status update
*/
protected boolean updateStatus(NodeState nodeStatus, boolean byNodeItself)
{
// First: do we have info for the node?
final IpAndPort endpoint = nodeStatus.getAddress();
if (endpoint == null) {
LOG.warn("Missing endpoint info (sender? "+byNodeItself+"); need to skip update");
return false;
}
// also, local state must be produced locally; ignore what others think
// (in future could try pro-active fixing but...)
if (endpoint.equals(_localState.getAddress())) {
return false;
}
ClusterPeerImpl peer;
try {
synchronized (_peers) {
peer = _peers.get(endpoint);
if (peer == null) { // Interesting: need to add a new entry
LOG.warn("Status for new node {} received: must create a peer", endpoint);
// node: should not ever occur for node itself... but...
_updateMissingPeer(nodeStatus, byNodeItself);
} else { // more common, just update...
// But first, see that information is more up-to-date
ActiveNodeState currentState = peer.getSyncState();
if (currentState.getLastUpdated() >= nodeStatus.getLastUpdated()) {
return false;
}
return _updateExistingPeer(nodeStatus, byNodeItself, peer);
}
}
} catch (IOException e) {
LOG.warn("Failed to update Node status for "+endpoint+": "+e.getMessage(), e);
}
return false;
}
/**
* Method called when we get information on a peer for which we have
* peer object and status information; so generally just need to merge
* it.
*/
protected boolean _updateExistingPeer(NodeState nodeStatus, boolean forSender,
ClusterPeerImpl peer) throws IOException
{
// final IpAndPort endpoint = nodeStatus.getAddress();
// !!! TODO: actual updating...
return false;
}
/**
* Method called when we get information on a peer for which we do not
* have peer thread.
*/
protected void _updateMissingPeer(NodeState nodeStatus, boolean forSender) throws IOException
{
final IpAndPort endpoint = nodeStatus.getAddress();
/* Ok: let's also see if we have old state information in the
* local DB. If we do, we may be able to avoid syncing from
* the beginning of time; and/or obtain actual key range.
*/
NodeStateStore stateStore = _stores.getNodeStore();
ActiveNodeState initialStatus = new ActiveNodeState(_localState, nodeStatus,
_timeMaster.currentTimeMillis());
// TODO: should perhaps also find by index + range?
ActiveNodeState oldState = stateStore.findEntry(endpoint);
ClusterPeerImpl peer = null;
// First common case: info was persisted earlier; we just "unthaw it"
if (oldState != null) {
if (oldState.equals(initialStatus)) {
peer = _createPeer(oldState);
_peers.put(endpoint, peer);
LOG.info("Restoring node {} from persisted data: no change", endpoint);
} else {
// Some changes; but is the sync range unaffected?
}
} else { // No info, just create with info we received
}
if (peer != null) {
_peers.put(endpoint, peer);
peer.startSyncing();
LOG.info("Started a new Peer thread for {}", endpoint);
}
}
/*
/**********************************************************************
/* Advanced accessors
/**********************************************************************
*/
@Override
public int getActiveCoverage()
{
ArrayList ranges = new ArrayList();
ranges.add(_localState.getRangeActive());
for (ClusterPeer peer : getPeers()) {
ranges.add(peer.getActiveRange());
}
return _keyspace.getCoverage(ranges);
}
@Override
public int getActiveCoveragePct() {
return _coveragePct(getActiveCoverage());
}
@Override
public int getTotalCoverage()
{
ArrayList ranges = new ArrayList();
ranges.add(_localState.totalRange());
for (ClusterPeer peer : getPeers()) {
ranges.add(peer.getTotalRange());
}
return _keyspace.getCoverage(ranges);
}
@Override
public int getTotalCoveragePct() {
return _coveragePct(getTotalCoverage());
}
@Override
public ClusterStatusMessage asMessage(boolean includeRemote) {
RemoteCluster rc = (!includeRemote || (_remoteClusterHandler == null)) ?
null : _remoteClusterHandler.getRemoteCluster();
return new ClusterStatusMessage(_timeMaster.currentTimeMillis(),
getLastUpdated(), getLocalState(), getPeerStates(),
(rc == null) ? null : rc.asNodeStates());
}
@Override
public long getHashOverState()
{
int hash = _keyspace.hashCode();
hash ^= _localState.hashCode();
for (ClusterPeerImpl peer : _peerImpls()) {
hash += peer.getSyncState().hashCode();
}
return hash;
}
/*
/**********************************************************************
/* Adding cluster info in requests, responses
/**********************************************************************
*/
@Override
public ServiceResponse addClusterStateInfo(ServiceResponse response)
{
long clusterUpdated = getLastUpdated();
return response.addHeader(ClusterMateConstants.CUSTOM_HTTP_HEADER_LAST_CLUSTER_UPDATE,
clusterUpdated);
}
@Override
public > B addClusterStateInfo(B requestBuilder)
{
/* Since key range information will be included anyway, all we need here
* is just the endpoint name ("caller").
*/
return requestBuilder.addParameter(ClusterMateConstants.QUERY_PARAM_CALLER,
_localState.getAddress().toString());
}
/*
/**********************************************************************
/* Internal methods
/**********************************************************************
*/
private int _coveragePct(int absCoverage) {
int len = _keyspace.getLength();
if (absCoverage == len) {
return 100;
}
return (int) ((100.0 * absCoverage) / len);
}
protected List> _peerImpls() {
synchronized (_peers) {
return new ArrayList>(_peers.values());
}
}
}