org.jgroups.protocols.relay.Relayer Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
package org.jgroups.protocols.relay;
import org.jgroups.*;
import org.jgroups.logging.Log;
import org.jgroups.protocols.relay.config.RelayConfig;
import org.jgroups.stack.AddressGenerator;
import org.jgroups.util.UUID;
import org.jgroups.util.Util;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ConcurrentMap;
/**
* Maintains bridges and routing table. Does the routing of outgoing messages and dispatches incoming messages to
* the right members.
* A Relayer cannot be reused once it is stopped, but a new Relayer instance must be created.
* @author Bela Ban
* @since 3.2
*/
public class Relayer {
/** The routing table. Site IDs are the keys (e.g. "sfo", and list of routes are the values */
protected ConcurrentMap> routes=new ConcurrentHashMap<>(5);
/** The bridges which are used to connect to different sites */
protected final Queue bridges=new ConcurrentLinkedQueue<>();
protected final Log log;
protected final RELAY2 relay;
/** Flag set when stop() is called. Since a Relayer should not be used after stop() has been called, a new
* instance needs to be created */
protected volatile boolean done;
protected boolean stats;
// Used to store messages for a site with status UNKNOWN. Messages will be flushed when the status changes to UP, or
// a SITE-UNREACHABLE message will be sent to each member *once* when the status changes to DOWN
// protected final ConcurrentMap> fwd_queue=new ConcurrentHashMap>();
// /** Map to store tasks which set the status of a site from UNKNOWN to DOWN. These are started when a site is
// * set to UNKNOWN, but they need to be cancelled when the status goes from UNKNOWN back to UP before
// * they kick in.*/
// protected final ConcurrentMap> down_tasks=new ConcurrentHashMap>();
//
public Relayer(RELAY2 relay, Log log) {
this.relay=relay;
this.stats=relay.statsEnabled();
this.log=log;
}
public boolean done() {return done;}
/**
* Creates all bridges from site_config and connects them (joining the bridge clusters)
* @param bridge_configs A list of bridge configurations
* @param bridge_name The name of the local bridge channel, prefixed with '_'.
* @param my_site_id The ID of this site
* @throws Throwable
*/
public void start(List bridge_configs, String bridge_name, final String my_site_id)
throws Throwable {
if(done) {
log.trace(relay.getLocalAddress() + ": will not start the Relayer as stop() has been called");
return;
}
try {
for(RelayConfig.BridgeConfig bridge_config: bridge_configs) {
Bridge bridge=new Bridge(bridge_config.createChannel(), bridge_config.getClusterName(), bridge_name,
new AddressGenerator() {
public Address generateAddress() {
UUID uuid=UUID.randomUUID();
return new SiteUUID(uuid, null, my_site_id);
}
});
bridges.add(bridge);
}
for(Bridge bridge: bridges)
bridge.start();
}
catch(Throwable t) {
stop();
throw t;
}
finally {
if(done) {
log.trace(relay.getLocalAddress() + ": stop() was called while starting the relayer; stopping the relayer now");
stop();
}
}
}
/**
* Disconnects and destroys all bridges
*/
public void stop() {
done=true;
for(Bridge bridge: bridges)
bridge.stop();
bridges.clear();
}
public synchronized String printRoutes() {
StringBuilder sb=new StringBuilder();
for(Map.Entry> entry: routes.entrySet()) {
List list=entry.getValue();
if(list != null && !list.isEmpty())
sb.append(entry.getKey() + " --> ").append(Util.print(list)).append("\n");
}
return sb.toString();
}
/**
* Grabs a random route
* @param site
* @return
*/
protected synchronized Route getRoute(String site) {
List list=routes.get(site);
return list == null? null : Util.pickRandomElement(list);
}
protected List getSiteNames() {
return new ArrayList<>(routes.keySet());
}
protected synchronized List getRoutes(String ... excluded_sites) {
List retval=new ArrayList<>(routes.size());
for(List list: routes.values()) {
for(Route route: list) {
if(route != null) {
if(!isExcluded(route, excluded_sites)) {
retval.add(route);
break;
}
}
}
}
return retval;
}
protected View getBridgeView(String cluster_name) {
if(cluster_name == null || bridges == null)
return null;
for(Bridge bridge: bridges) {
if(bridge.cluster_name != null && bridge.cluster_name.equals(cluster_name))
return bridge.view;
}
return null;
}
protected static boolean isExcluded(Route route, String... excluded_sites) {
if(excluded_sites == null)
return false;
String site=((SiteUUID)route.site_master).getSite();
for(String excluded_site: excluded_sites)
if(site.equals(excluded_site))
return true;
return false;
}
/**
* Includes information about the site master of the route and the channel to be used
*/
public class Route implements Comparable {
/** SiteUUID: address of the site master */
protected final Address site_master;
protected final JChannel bridge;
public Route(Address site_master, JChannel bridge) {
this.site_master=site_master;
this.bridge=bridge;
}
public JChannel bridge() {return bridge;}
public Address siteMaster() {return site_master;}
public void send(Address final_destination, Address original_sender, final Message msg) {
if(log.isTraceEnabled())
log.trace("routing message to " + final_destination + " via " + site_master);
long start=stats? System.nanoTime() : 0;
try {
Message copy=createMessage(site_master, final_destination, original_sender, msg);
bridge.send(copy);
if(stats) {
relay.addToRelayedTime(System.nanoTime() - start);
relay.incrementRelayed();
}
}
catch(Exception e) {
log.error("failure relaying message", e);
}
}
public int compareTo(Route o) {
return site_master.compareTo(o.siteMaster());
}
public boolean equals(Object obj) {
return compareTo((Route)obj) == 0;
}
public int hashCode() {
return site_master.hashCode();
}
public String toString() {
return (site_master != null? site_master.toString() : "");
}
protected Message createMessage(Address target, Address final_destination, Address original_sender, final Message msg) {
Message copy=relay.copy(msg).dest(target).src(null);
RELAY2.Relay2Header hdr=new RELAY2.Relay2Header(RELAY2.Relay2Header.DATA, final_destination, original_sender);
copy.putHeader(relay.getId(), hdr);
return copy;
}
}
protected class Bridge extends ReceiverAdapter {
protected JChannel channel;
protected final String cluster_name;
protected View view;
protected Bridge(final JChannel ch, final String cluster_name, String channel_name, AddressGenerator addr_generator) throws Exception {
this.channel=ch;
channel.setName(channel_name);
channel.setReceiver(this);
channel.addAddressGenerator(addr_generator);
this.cluster_name=cluster_name;
}
protected void start() throws Exception {
channel.connect(cluster_name);
log.info("%s: joined bridge cluster '%s'", channel.getAddress(), cluster_name);
}
protected void stop() {
log.info("%s: leaving bridge cluster '%s'", channel.getAddress(), channel.getClusterName());
Util.close(channel);
}
public void receive(Message msg) {
RELAY2.Relay2Header hdr=(RELAY2.Relay2Header)msg.getHeader(relay.getId());
if(hdr == null) {
log.warn("received a message without a relay header; discarding it");
return;
}
relay.handleRelayMessage(hdr, msg);
}
/** The view contains a list of SiteUUIDs. Adjust the routing table based on the SiteUUIDs UUID and site
*/
public void viewAccepted(View new_view) {
this.view=new_view;
log.trace("[Relayer " + channel.getAddress() + "] view: " + new_view);
RouteStatusListener listener=relay.getRouteStatusListener();
Map> tmp=extract(new_view);
Set down=listener != null? new HashSet<>(routes.keySet()) : null;
Set up=listener != null? new HashSet() : null;
if(listener != null)
down.removeAll(tmp.keySet());
routes.keySet().retainAll(tmp.keySet()); // remove all sites which are not in the view
for(Map.Entry> entry: tmp.entrySet()) {
String key=entry.getKey();
List val=entry.getValue();
if(!routes.containsKey(key)) {
routes.put(key, new ArrayList());
if(up != null)
up.add(key);
}
List list=routes.get(key);
// Remove routes not in the view anymore:
for(Iterator it=list.iterator(); it.hasNext();) {
Route route=it.next();
if(!val.contains(route.siteMaster()))
it.remove();
}
// Add routes that aren't yet in the routing table:
for(Address addr: val) {
if(!contains(list, addr))
list.add(new Route(addr, channel));
}
if(list.isEmpty()) {
routes.remove(key);
if(listener != null) {
down.add(key);
up.remove(key);
}
}
}
if(listener != null) {
if(!down.isEmpty())
listener.sitesDown(down.toArray(new String[down.size()]));
if(!up.isEmpty())
listener.sitesUp(up.toArray(new String[up.size()]));
}
}
protected boolean contains(List routes, Address addr) {
for(Route route: routes) {
if(route.siteMaster().equals(addr))
return true;
}
return false;
}
/** Returns a map containing the site keys and addresses as values */
protected Map> extract(View view) {
Map> map=new HashMap<>(view.size());
for(Address mbr: view) {
SiteAddress member=(SiteAddress)mbr;
String key=member.getSite();
List list=map.get(key);
if(list == null) {
list=new ArrayList<>();
map.put(key, list);
}
if(!list.contains(member))
list.add(member);
}
return map;
}
}
}