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NoSQL Database Server - supplies build and runtime support for the server (store) side of the Oracle NoSQL Database.
/*-
* Copyright (C) 2011, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This file was distributed by Oracle as part of a version of Oracle NoSQL
* Database made available at:
*
* http://www.oracle.com/technetwork/database/database-technologies/nosqldb/downloads/index.html
*
* Please see the LICENSE file included in the top-level directory of the
* appropriate version of Oracle NoSQL Database for a copy of the license and
* additional information.
*/
package oracle.kv.impl.util;
import java.rmi.NotBoundException;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.Registry;
import java.util.Arrays;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import oracle.kv.FaultException;
import oracle.kv.KVSecurityException;
import oracle.kv.KVStoreException;
import oracle.kv.impl.fault.InternalFaultException;
import oracle.kv.impl.rep.admin.RepNodeAdmin;
import oracle.kv.impl.rep.admin.RepNodeAdminAPI;
import oracle.kv.impl.security.SessionAccessException;
import oracle.kv.impl.security.login.LoginHandle;
import oracle.kv.impl.security.login.LoginManager;
import oracle.kv.impl.topo.RepGroup;
import oracle.kv.impl.topo.RepNode;
import oracle.kv.impl.topo.ResourceId.ResourceType;
import oracle.kv.impl.topo.Topology;
import oracle.kv.impl.util.registry.RegistryUtils;
/**
* Locates a current Topology given a list of SN registry locations
*/
public class TopologyLocator {
public static final String HOST_PORT_SEPARATOR = ":";
/**
* Obtains a current topology from the SNs identified via
* registryHostPorts.
*
* The location of the Topology is done as a two step process.
*
* - It first identifies an initial Topology that is the most up to date
* one know to the RNs hosted by the supplied SNs.
* -
* If
maxRNs > 0 it then uses the initial Topology to
* further search some bounded number of RNs, for an even more up to date
* Topology and returns it.
*
*
* @param registryHostPorts one or more strings containing the registry
* host and port associated with the SN. Each string has the format:
* hostname:port.
*
* @param maxRNs the maximum number of RNs to examine for an up to date
* Topology. If maxRNs == 0 then the initial topology is returned.
*
* @param loginMgr a login manager that will be used to supply login tokens
* to api calls.
*/
public static Topology get(String[] registryHostPorts,
int maxRNs,
LoginManager loginMgr,
String expectedStoreName)
throws KVStoreException {
/* The highest topo seq # found */
final AtomicInteger maxTopoSeqNum = new AtomicInteger(0);
final Topology initialTopology = getInitialTopology(registryHostPorts,
maxTopoSeqNum,
loginMgr,
expectedStoreName);
assert maxTopoSeqNum.get() > 0;
if (maxRNs <= 0) {
return initialTopology;
}
/* Keep the pool large enough to minimize the odds of a stall */
final int poolSize = Math.max(maxRNs, 10);
final ThreadPoolExecutor executor =
new ThreadPoolExecutor(poolSize, // corePoolSize
poolSize, // maximumPoolSize - ignored
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue(),
new KVThreadFactory(" topology locator",
null));
/* The number of RNs to check */
final AtomicInteger nRNs = new AtomicInteger(maxRNs);
/*
* Now use the initial Topology to find an even more current version
* if it exists.
*/
final AtomicReference currentAdmin =
new AtomicReference();
final RegistryUtils registryUtils =
new RegistryUtils(initialTopology, loginMgr);
for (RepGroup rg : initialTopology.getRepGroupMap().getAll()) {
for (final RepNode rn : rg.getRepNodes()) {
executor.submit(new Runnable() {
@Override
public void run() {
if (nRNs.get() <= 0) {
return;
}
try {
RepNodeAdminAPI admin =
registryUtils.getRepNodeAdmin(rn.getResourceId());
int seqNum = admin.getTopoSeqNum();
synchronized (maxTopoSeqNum) {
if (seqNum > maxTopoSeqNum.get()) {
maxTopoSeqNum.set(seqNum);
currentAdmin.set(admin);
}
}
nRNs.decrementAndGet();
} catch (SessionAccessException sae) {
} catch (RemoteException re) {
} catch (NotBoundException nbe) { }
}});
}
}
executor.shutdown();
/*
* Wait until the required number of RNs have been checked or all tasks
* have run.
*/
while (nRNs.get() > 0) {
try {
if (executor.awaitTermination(100L, TimeUnit.MILLISECONDS)) {
break;
}
} catch (InterruptedException ie) { }
}
executor.shutdownNow();
/* If a newer topo was found attempt to get it and return */
if (currentAdmin.get() != null) {
try {
return currentAdmin.get().getTopology();
} catch (RemoteException re) { }
}
/*
* If there was an issue getting the latest, or none newer were found
* return the initial topo.
*/
return initialTopology;
}
/**
* A convenience method to locate the initial topology, specifying a single
* host/port
* @param hostname
* @param port
* @return the initial topology that is found.
* @throws KVStoreException
*/
public static Topology get(String hostname,
int port) throws KVStoreException {
String[] hostports = new String[1];
hostports[0] = hostname + HOST_PORT_SEPARATOR + port;
return get(hostports, 0, null, null);
}
/**
* Locates an initial Topology based upon the supplied SNs. This method
* is intended for use in the KVS client and meets the client side
* exception interfaces.
*/
private static Topology getInitialTopology(String[] registryHostPorts,
final AtomicInteger maxTopoSeqNum,
final LoginManager loginMgr,
final String expectedStoreName)
throws KVStoreException {
/* The exception cause collector */
final AtomicReference cause =
new AtomicReference();
/* The RN admin which has the higest topo */
final AtomicReference currentAdmin =
new AtomicReference();
applyToRNs(registryHostPorts,
expectedStoreName,
"topology locator",
loginMgr,
cause,
new RNAdminCallback() {
@Override
public void callback(RepNodeAdminAPI rnAdmin)
throws RemoteException {
final int seqNum = rnAdmin.getTopoSeqNum();
synchronized (maxTopoSeqNum) {
if (seqNum > maxTopoSeqNum.get()) {
maxTopoSeqNum.set(seqNum);
currentAdmin.set(rnAdmin);
}
}
}
});
/*
* If no initial topology was found, can't continue so throw an
* exception
*/
if (currentAdmin.get() == null) {
/* If there was already a KVSecurityException, throw that */
if (cause.get() instanceof KVSecurityException) {
throw (KVSecurityException)cause.get();
}
/* If there was already a FaultException, throw that */
if (cause.get() instanceof FaultException) {
throw (FaultException)cause.get();
}
throw new KVStoreException
("Could not contact any RepNode at: " +
Arrays.toString(registryHostPorts), cause.get());
}
try {
return currentAdmin.get().getTopology();
} catch (RemoteException e) {
throw new KVStoreException
("Could not establish an initial Topology from: " +
Arrays.toString(registryHostPorts), cause.get());
} catch (InternalFaultException e) {
/* Clients expect FaultException */
throw new FaultException(e, false);
}
}
public static void applyToRNs(final String[] registryHostPorts,
final String expectedStoreName,
final String threadFactoryName,
final LoginManager loginMgr,
final AtomicReference cause,
final RNAdminCallback rnAdmincallback) {
final ThreadPoolExecutor executor =
new ThreadPoolExecutor(0, registryHostPorts.length,
0L, TimeUnit.MILLISECONDS,
new SynchronousQueue(),
new KVThreadFactory(" " + threadFactoryName,
null));
for (final String registryHostPort : registryHostPorts) {
executor.submit(new Runnable() {
@Override
public void run() {
final HostPort hostPort = HostPort.parse(registryHostPort);
final String registryHostname = hostPort.hostname();
final int registryPort = hostPort.port();
try {
final Registry snRegistry =
RegistryUtils.getRegistry(registryHostname,
registryPort,
expectedStoreName);
for (String serviceName : snRegistry.list()) {
try {
/**
* Skip things that don't look like RepNodes (this
* is for the client).
*/
if (!RegistryUtils.isRepNodeAdmin(serviceName)) {
continue;
}
final Remote stub = snRegistry.lookup(serviceName);
if (!(stub instanceof RepNodeAdmin)) {
continue;
}
final LoginHandle loginHdl =
(loginMgr == null) ?
null :
loginMgr.getHandle(new HostPort(
registryHostname, registryPort),
ResourceType.REP_NODE);
final RepNodeAdminAPI admin = RepNodeAdminAPI.
wrap((RepNodeAdmin) stub, loginHdl);
rnAdmincallback.callback(admin);
} catch (SessionAccessException e) {
cause.set(e);
} catch (RemoteException re) {
cause.set(re);
} catch (NotBoundException e) {
/*
* Should not happen since we are iterating over a
* bound list.
*/
cause.set(e);
} catch (InternalFaultException e) {
/*
* Be robust even in the presence of internal faults
* Keep trying with other functioning nodes.
* Preserve non-fault exception as the reason
* if one's already present.
*/
cause.compareAndSet(null, e);
} catch (Throwable e) {
cause.compareAndSet(null, e);
}
}
} catch (RemoteException e) {
cause.compareAndSet(null, e);
}
}});
}
/* Wait until all of the tasks have finished */
executor.shutdown();
try {
executor.awaitTermination(10L, TimeUnit.MINUTES); // Nearly forever
} catch (InterruptedException ie) {
/* Leave a more meaningful exception if one is present */
cause.compareAndSet(null, ie);
}
}
public interface RNAdminCallback {
void callback(RepNodeAdminAPI rnAdmin) throws RemoteException;
}
}
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