org.jgroups.protocols.Discovery Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including
all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and
Jakarta Messaging 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;
import org.jgroups.*;
import org.jgroups.annotations.MBean;
import org.jgroups.annotations.ManagedAttribute;
import org.jgroups.annotations.ManagedOperation;
import org.jgroups.annotations.Property;
import org.jgroups.conf.ConfiguratorFactory;
import org.jgroups.stack.IpAddress;
import org.jgroups.stack.Protocol;
import org.jgroups.util.*;
import org.jgroups.util.UUID;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.*;
import java.util.concurrent.TimeUnit;
/**
* The Discovery protocol retrieves the initial membership (used by GMS and MERGE3) by sending discovery requests.
* We do this in subclasses of Discovery, e.g. by mcasting a discovery request ({@link PING}) or, if gossiping is enabled,
* by contacting the GossipRouter ({@link TCPGOSSIP}).
* The responses should allow us to determine the coordinator which we have to contact, e.g. in case we want to join
* the group, or to see if we have diverging views in case of MERGE2.
* When we are a server (after having received the BECOME_SERVER event), we'll respond to discovery requests with
* a discovery response.
*
* @author Bela Ban
*/
@MBean
public abstract class Discovery extends Protocol {
/* ----------------------------------------- Properties -------------------------------------------------- */
@Deprecated
@Property(description="Timeout to wait for the initial members",deprecatedMessage="GMS.join_timeout should be used instead")
protected long timeout=3000;
@Deprecated
@Property(description="Minimum number of initial members to get a response from",deprecatedMessage="will be ignored")
protected int num_initial_members=10;
@Deprecated
@Property(description="Minimum number of server responses (PingData.isServer()=true). If this value is " +
"greater than 0, we'll ignore num_initial_members",deprecatedMessage="not used anymore")
protected int num_initial_srv_members;
@Property(description="Return from the discovery phase as soon as we have 1 coordinator response")
protected boolean break_on_coord_rsp=true;
@Property(description="Whether or not to return the entire logical-physical address cache mappings on a " +
"discovery request, or not.")
protected boolean return_entire_cache=false;
@Property(description="If greater than 0, we'll wait a random number of milliseconds in range [0..stagger_timeout] " +
"before sending a discovery response. This prevents traffic spikes in large clusters when everyone sends their " +
"discovery response at the same time")
protected long stagger_timeout;
@Property(description="Always sends a discovery response, no matter what",writable=true)
protected boolean force_sending_discovery_rsps=true;
@Property(description="If a persistent disk cache (PDC) is present, combine the discovery results with the " +
"contents of the disk cache before returning the results")
protected boolean use_disk_cache=false;
@Deprecated
@Property(description="When sending a discovery request, always send the physical address and logical name too",
deprecatedMessage="ignored")
protected boolean always_send_physical_addr_with_discovery_request=true;
@Property(description="Max size of the member list shipped with a discovery request. If we have more, the " +
"mbrs field in the discovery request header is nulled and members return the entire membership, " +
"not individual members")
protected int max_members_in_discovery_request=500;
@Property(description="Expiry time of discovery responses in ms")
protected long discovery_rsp_expiry_time=60000;
@Property(description="If true then the discovery is done on a separate timer thread. Should be set to true when " +
"discovery is blocking and/or takes more than a few milliseconds")
protected boolean async_discovery=false;
@Property(description="When a new node joins, and we have a static discovery protocol (TCPPING), then send the " +
"contents of the discovery cache to new and existing members if true (and we're the coord). Addresses JGRP-1903")
protected boolean send_cache_on_join=false;
@ManagedOperation(description="Sets force_sending_discovery_rsps")
public void setForceSendingDiscoveryRsps(boolean flag) {
force_sending_discovery_rsps=flag;
}
/* --------------------------------------------- JMX ------------------------------------------------------ */
@ManagedAttribute(description="Total number of discovery requests sent ")
protected int num_discovery_requests;
/* --------------------------------------------- Fields ------------------------------------------------------ */
protected volatile boolean is_server=false;
protected volatile boolean is_leaving=false;
protected TimeScheduler timer;
protected View view;
protected final List members=new ArrayList<>(11);
@ManagedAttribute(description="Whether this member is the current coordinator")
protected boolean is_coord=false;
protected Address local_addr=null;
protected Address current_coord;
protected String cluster_name;
protected final Map ping_responses=new HashMap<>();
@ManagedAttribute(description="Whether the transport supports multicasting")
protected boolean transport_supports_multicasting=true;
protected static final byte[] WHITESPACE=" \t".getBytes();
public void init() throws Exception {
timer=getTransport().getTimer();
if(timer == null)
throw new Exception("timer cannot be retrieved from protocol stack");
if(stagger_timeout < 0)
throw new IllegalArgumentException("stagger_timeout cannot be negative");
transport_supports_multicasting=getTransport().supportsMulticasting();
}
public abstract boolean isDynamic();
public void handleDisconnect() {
}
public void handleConnect() {
}
public void discoveryRequestReceived(Address sender, String logical_name, PhysicalAddress physical_addr) {
}
public long getTimeout() {return timeout;}
public void setTimeout(long timeout) {this.timeout=timeout;}
@Deprecated
public int getNumInitialMembers() {return -1;}
@Deprecated
public void setNumInitialMembers(int num) {}
public int getNumberOfDiscoveryRequestsSent() {return num_discovery_requests;}
public long timeout() {return timeout;}
public Discovery timeout(long timeout) {this.timeout=timeout; return this;}
@Deprecated
public long numInitialMembers() {return -1;}
@Deprecated
public Discovery numInitialMembers(int num) {return this;}
public boolean breakOnCoordResponse() {return break_on_coord_rsp;}
public Discovery breakOnCoordResponse(boolean flag) {break_on_coord_rsp=flag; return this;}
public boolean returnEntireCache() {return return_entire_cache;}
public Discovery returnEntireCache(boolean flag) {return_entire_cache=flag; return this;}
public long staggerTimeout() {return stagger_timeout;}
public Discovery staggerTimeout(long timeout) {stagger_timeout=timeout; return this;}
public boolean forceDiscoveryResponses() {return force_sending_discovery_rsps;}
public Discovery forceDiscoveryResponses(boolean f) {force_sending_discovery_rsps=f; return this;}
public boolean useDiskCache() {return use_disk_cache;}
public Discovery useDiskCache(boolean flag) {use_disk_cache=flag; return this;}
@ManagedAttribute
public String getView() {return view != null? view.getViewId().toString() : "null";}
public ViewId getViewId() {
return view != null? view.getViewId() : null;
}
@ManagedAttribute(description="The address of the current coordinator")
public String getCurrentCoord() {return current_coord != null? current_coord.toString() : "n/a";}
protected boolean isMergeRunning() {
Object retval=up_prot.up(new Event(Event.IS_MERGE_IN_PROGRESS));
return retval instanceof Boolean && (Boolean)retval;
}
@ManagedOperation(description="Sends information about my cache to everyone but myself")
public void sendCacheInformation() {
List current_members=null;
synchronized(members) {
current_members=new ArrayList<>(members);
}
disseminateDiscoveryInformation(current_members, null, current_members);
}
public List providedUpServices() {
return Arrays.asList(Event.FIND_INITIAL_MBRS, Event.GET_PHYSICAL_ADDRESS, Event.FIND_MBRS);
}
public void resetStats() {
super.resetStats();
num_discovery_requests=0;
}
public void start() throws Exception {
super.start();
}
public void stop() {
is_server=false;
}
/**
* Fetches information (e.g. physical address, logical name) for the given member addresses. Needs to add responses
* to the {@link org.jgroups.util.Responses} object. If {@link #async_discovery} is true, this method will be called
* in a separate thread, otherwise the caller's thread will be used.
* @param members A list of logical addresses (typically {@link org.jgroups.util.UUID}s). If null, then information
* for all members is fetched
* @param initial_discovery Set to true if this is for the initial membership discovery. Some protocols (e.g.
* file based ones) may return only the information for the coordinator(s).
* @param responses The list to which responses should be added
*/
protected abstract void findMembers(List members, boolean initial_discovery, Responses responses);
public Responses findMembers(final List members, final boolean initial_discovery, boolean async) {
num_discovery_requests++;
int num_expected=members != null? members.size() : 0;
int capacity=members != null? members.size() : 16;
final Responses rsps=new Responses(num_expected, initial_discovery && break_on_coord_rsp, capacity);
synchronized(ping_responses) {
ping_responses.put(System.nanoTime(), rsps);
}
if(async || async_discovery) {
timer.execute(new Runnable() {
public void run() {findMembers(members, initial_discovery, rsps);}
});
}
else
findMembers(members, initial_discovery, rsps);
return rsps;
}
@ManagedOperation(description="Runs the discovery protocol to find initial members")
public String findInitialMembersAsString() {
Responses rsps=findMembers(null, false, false);
if(!rsps.isDone())
rsps.waitFor(300);
if(rsps.isEmpty()) return "";
StringBuilder sb=new StringBuilder();
for(PingData rsp: rsps)
sb.append(rsp).append("\n");
return sb.toString();
}
@ManagedOperation(description="Reads logical-physical address mappings and logical name mappings from a " +
"file (or URL) and adds them to the local caches")
public void addToCache(String filename) throws Exception {
InputStream in=ConfiguratorFactory.getConfigStream(filename);
List list=read(in);
if(list != null)
for(PingData data: list)
addDiscoveryResponseToCaches(data.getAddress(), data.getLogicalName(), data.getPhysicalAddr());
}
@ManagedOperation(description="Reads data from local caches and dumps them to a file")
public void dumpCache(String output_filename) throws Exception {
Map cache_contents=
(Map)down_prot.down(new Event(Event.GET_LOGICAL_PHYSICAL_MAPPINGS, false));
List list=new ArrayList<>(cache_contents.size());
for(Map.Entry entry: cache_contents.entrySet()) {
Address addr=entry.getKey();
PhysicalAddress phys_addr=entry.getValue();
PingData data=new PingData(addr, true, UUID.get(addr), phys_addr).coord(addr.equals(local_addr));
list.add(data);
}
OutputStream out=new FileOutputStream(output_filename);
write(list, out);
}
@SuppressWarnings("unchecked")
public Object up(Event evt) {
switch(evt.getType()) {
case Event.MSG:
Message msg=(Message)evt.getArg();
PingHeader hdr=(PingHeader)msg.getHeader(this.id);
if(hdr == null)
return up_prot.up(evt);
if(is_leaving)
return null; // prevents merging back a leaving member (https://issues.jboss.org/browse/JGRP-1336)
PingData data=readPingData(msg.getRawBuffer(), msg.getOffset(), msg.getLength());
Address logical_addr=data != null? data.getAddress() : msg.src();
switch(hdr.type) {
case PingHeader.GET_MBRS_REQ: // return Rsp(local_addr, coord)
if(cluster_name == null || hdr.cluster_name == null) {
log.warn("cluster_name (%s) or cluster_name of header (%s) is null; passing up discovery " +
"request from %s, but this should not be the case", cluster_name, hdr.cluster_name, msg.src());
}
else {
if(!cluster_name.equals(hdr.cluster_name)) {
log.warn("%s: discarding discovery request for cluster '%s' from %s; " +
"our cluster name is '%s'. Please separate your clusters properly",
logical_addr, hdr.cluster_name, msg.src(), cluster_name);
return null;
}
}
// add physical address and logical name of the discovery sender (if available) to the cache
if(data != null) {
addDiscoveryResponseToCaches(logical_addr, data.getLogicalName(), data.getPhysicalAddr());
discoveryRequestReceived(msg.getSrc(), data.getLogicalName(), data.getPhysicalAddr());
addResponse(data, false);
}
if(return_entire_cache) {
Map cache=(Map)down(new Event(Event.GET_LOGICAL_PHYSICAL_MAPPINGS));
if(cache != null) {
for(Map.Entry entry: cache.entrySet()) {
Address addr=entry.getKey();
// JGRP-1492: only return our own address, and addresses in view.
if(addr.equals(local_addr) || members.contains(addr)) {
PhysicalAddress physical_addr=entry.getValue();
sendDiscoveryResponse(addr, physical_addr, UUID.get(addr), msg.getSrc(), isCoord(addr));
}
}
}
return null;
}
// Only send a response if hdr.mbrs is not empty and contains myself. Otherwise always send my info
Collection mbrs=data != null? data.mbrs() : null;
boolean send_response=mbrs == null || mbrs.contains(local_addr);
if(send_response) {
PhysicalAddress physical_addr=(PhysicalAddress)down(new Event(Event.GET_PHYSICAL_ADDRESS, local_addr));
sendDiscoveryResponse(local_addr, physical_addr, UUID.get(local_addr), msg.getSrc(), is_coord);
}
return null;
case PingHeader.GET_MBRS_RSP:
// add physical address (if available) to transport's cache
if(data != null) {
log.trace("%s: received GET_MBRS_RSP from %s: %s", local_addr, msg.src(), data);
handleDiscoveryResponse(data, msg.src());
}
return null;
default:
log.warn("got PING header with unknown type %d", hdr.type);
return null;
}
case Event.FIND_MBRS:
return findMembers((List)evt.getArg(), false, true); // this is done asynchronously
}
return up_prot.up(evt);
}
protected void handleDiscoveryResponse(PingData data, Address sender) {
// add physical address (if available) to transport's cache
Address logical_addr=data.getAddress() != null? data.getAddress() : sender;
addDiscoveryResponseToCaches(logical_addr, data.getLogicalName(), data.getPhysicalAddr());
boolean overwrite=logical_addr != null && logical_addr.equals(sender);
addResponse(data, overwrite);
}
@SuppressWarnings("unchecked")
public Object down(Event evt) {
switch(evt.getType()) {
case Event.FIND_INITIAL_MBRS: // sent by GMS layer
return findMembers(null, true, false); // triggered by JOIN process (ClientGmsImpl)
case Event.FIND_MBRS:
return findMembers((List)evt.getArg(), false, false); // triggered by MERGE2/MERGE3
// case Event.TMP_VIEW:
case Event.VIEW_CHANGE:
List tmp;
View old_view=view;
view=(View)evt.getArg();
if((tmp=view.getMembers()) != null) {
synchronized(members) {
members.clear();
members.addAll(tmp);
}
}
current_coord=!members.isEmpty()? members.get(0) : null;
is_coord=current_coord != null && local_addr != null && current_coord.equals(local_addr);
Object retval=down_prot.down(evt);
if(send_cache_on_join && !isDynamic() && is_coord) {
List curr_mbrs, left_mbrs, new_mbrs;
synchronized(members) {
curr_mbrs=new ArrayList<>(members);
left_mbrs=old_view != null? Util.leftMembers(old_view.getMembers(), members) : null;
new_mbrs=old_view != null? Util.newMembers(old_view.getMembers(), members) : null;
}
startCacheDissemination(curr_mbrs, left_mbrs, new_mbrs); // separate task
}
return retval;
case Event.BECOME_SERVER: // called after client has joined and is fully working group member
down_prot.down(evt);
is_server=true;
return null;
case Event.SET_LOCAL_ADDRESS:
local_addr=(Address)evt.getArg();
return down_prot.down(evt);
case Event.CONNECT:
case Event.CONNECT_WITH_STATE_TRANSFER:
case Event.CONNECT_USE_FLUSH:
case Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH:
is_leaving=false;
cluster_name=(String)evt.getArg();
Object ret=down_prot.down(evt);
handleConnect();
return ret;
case Event.DISCONNECT:
is_leaving=true;
handleDisconnect();
return down_prot.down(evt);
default:
return down_prot.down(evt); // Pass on to the layer below us
}
}
/* -------------------------- Private methods ---------------------------- */
protected List read(InputStream in) {
List retval=null;
try {
while(true) {
try {
String name_str=Util.readToken(in);
String uuid_str=Util.readToken(in);
String addr_str=Util.readToken(in);
String coord_str=Util.readToken(in);
if(name_str == null || uuid_str == null || addr_str == null || coord_str == null)
break;
UUID uuid=null;
try {
long tmp=Long.valueOf(uuid_str);
uuid=new UUID(0, tmp);
}
catch(Throwable t) {
uuid=UUID.fromString(uuid_str);
}
PhysicalAddress phys_addr=new IpAddress(addr_str);
boolean is_coordinator=coord_str.trim().equals("T") || coord_str.trim().equals("t");
if(retval == null)
retval=new ArrayList<>();
retval.add(new PingData(uuid, true, name_str, phys_addr).coord(is_coordinator));
}
catch(Throwable t) {
log.error("failed reading line of input stream", t);
}
}
return retval;
}
finally {
Util.close(in);
}
}
protected void write(List list, OutputStream out) throws Exception {
try {
for(PingData data: list) {
String logical_name=data.getLogicalName();
Address addr=data.getAddress();
PhysicalAddress phys_addr=data.getPhysicalAddr();
if(logical_name == null || addr == null || phys_addr == null)
continue;
out.write(logical_name.getBytes());
out.write(WHITESPACE);
out.write(addressAsString(addr).getBytes());
out.write(WHITESPACE);
out.write(phys_addr.toString().getBytes());
out.write(WHITESPACE);
out.write(data.isCoord()? "T\n".getBytes() : "F\n".getBytes());
}
}
finally {
Util.close(out);
}
}
protected void addResponse(PingData rsp, boolean overwrite) {
synchronized(ping_responses) {
for(Iterator> it=ping_responses.entrySet().iterator(); it.hasNext();) {
Map.Entry entry=it.next();
long timestamp=entry.getKey();
Responses rsps=entry.getValue();
rsps.addResponse(rsp, overwrite);
if(rsps.isDone() || TimeUnit.MILLISECONDS.convert(System.nanoTime() - timestamp, TimeUnit.NANOSECONDS) > discovery_rsp_expiry_time) {
it.remove();
rsps.done();
}
}
}
}
protected boolean addDiscoveryResponseToCaches(Address mbr, String logical_name, PhysicalAddress physical_addr) {
if(mbr == null)
return false;
if(logical_name != null)
UUID.add(mbr, logical_name);
if(physical_addr != null)
return (Boolean)down(new Event(Event.SET_PHYSICAL_ADDRESS, new Tuple<>(mbr, physical_addr)));
return false;
}
protected synchronized void startCacheDissemination(List curr_mbrs, List left_mbrs, List new_mbrs) {
timer.execute(new DiscoveryCacheDisseminationTask(curr_mbrs,left_mbrs,new_mbrs));
}
/**
* Creates a byte[] representation of the PingData, but DISCARDING the view it contains.
* @param data the PingData instance to serialize.
* @return
*/
protected byte[] serializeWithoutView(PingData data) {
final PingData clone = new PingData(data.getAddress(), data.isServer(), data.getLogicalName(), data.getPhysicalAddr()).coord(data.isCoord());
try {
return Util.streamableToByteBuffer(clone);
}
catch(Exception e) {
log.error("error serializing PingData", e);
return null;
}
}
protected static PingData deserialize(final byte[] data) throws Exception {
return (PingData)Util.streamableFromByteBuffer(PingData.class, data);
}
public static Buffer marshal(PingData data) {
return Util.streamableToBuffer(data);
}
protected PingData readPingData(byte[] buffer, int offset, int length) {
try {
return buffer != null? Util.streamableFromBuffer(PingData.class, buffer, offset, length) : null;
}
catch(Exception ex) {
log.error("%s: failed reading PingData from message: %s", local_addr, ex);
return null;
}
}
protected void sendDiscoveryResponse(Address logical_addr, PhysicalAddress physical_addr,
String logical_name, final Address sender, boolean coord) {
final PingData data=new PingData(logical_addr, is_server, logical_name, physical_addr).coord(coord);
final Message rsp_msg=new Message(sender).setFlag(Message.Flag.INTERNAL, Message.Flag.OOB, Message.Flag.DONT_BUNDLE)
.putHeader(this.id, new PingHeader(PingHeader.GET_MBRS_RSP)).setBuffer(marshal(data));
if(stagger_timeout > 0) {
int view_size=view != null? view.size() : 10;
int rank=Util.getRank(view, local_addr); // returns 0 if view or local_addr are null
long sleep_time=rank == 0? Util.random(stagger_timeout)
: stagger_timeout * rank / view_size - (stagger_timeout / view_size);
timer.schedule(new Runnable() {
public void run() {
log.trace("%s: received GET_MBRS_REQ from %s, sending staggered response %s", local_addr, sender, data);
down_prot.down(new Event(Event.MSG, rsp_msg));
}
}, sleep_time, TimeUnit.MILLISECONDS);
return;
}
log.trace("%s: received GET_MBRS_REQ from %s, sending response %s", local_addr, sender, data);
down_prot.down(new Event(Event.MSG, rsp_msg));
}
protected static String addressAsString(Address address) {
if(address == null)
return "";
if(address instanceof UUID)
return ((UUID) address).toStringLong();
return address.toString();
}
protected boolean isCoord(Address member) {return member.equals(current_coord);}
/** Disseminates cache information (UUID/IP adddress/port/name) to the given members
* @param current_mbrs The current members. Guaranteed to be non-null. This is a copy and can be modified.
* @param left_mbrs The members which left. These are excluded from dissemination. Can be null if no members left
* @param new_mbrs The new members that we need to disseminate the information to. Will be all members if null.
*/
protected void disseminateDiscoveryInformation(List current_mbrs, List left_mbrs, List new_mbrs) {
if(new_mbrs == null || new_mbrs.isEmpty())
return;
if(local_addr != null)
current_mbrs.remove(local_addr);
if(left_mbrs != null)
current_mbrs.removeAll(left_mbrs);
// 1. Send information about to new_mbrs
Set info=new HashSet(current_mbrs);
for(Address addr : info) {
PhysicalAddress phys_addr=(PhysicalAddress)down_prot.down(new Event(Event.GET_PHYSICAL_ADDRESS,addr));
if(phys_addr == null)
continue;
boolean is_coordinator=isCoord(addr);
for(Address target : new_mbrs)
sendDiscoveryResponse(addr,phys_addr,UUID.get(addr),target,is_coordinator);
}
// 2. Send information about new_mbrs to
Set targets=new HashSet(current_mbrs);
targets.removeAll(new_mbrs);
if(!targets.isEmpty()) {
for(Address addr : new_mbrs) {
PhysicalAddress phys_addr=(PhysicalAddress)down_prot.down(new Event(Event.GET_PHYSICAL_ADDRESS,addr));
if(phys_addr == null)
continue;
boolean is_coordinator=isCoord(addr);
for(Address target : targets)
sendDiscoveryResponse(addr,phys_addr,UUID.get(addr),target,is_coordinator);
}
}
}
protected class DiscoveryCacheDisseminationTask implements Runnable {
protected final List curr_mbrs, left_mbrs, new_mbrs;
public DiscoveryCacheDisseminationTask(List curr_mbrs,List left_mbrs,List new_mbrs) {
this.curr_mbrs=curr_mbrs;
this.left_mbrs=left_mbrs;
this.new_mbrs=new_mbrs;
}
public void run() {
disseminateDiscoveryInformation(curr_mbrs, left_mbrs, new_mbrs);
}
}
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