/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hdfs.server.datanode;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.security.UserGroupInformation;
import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
/**
* Manages the BPOfferService objects for the data node.
* Creation, removal, starting, stopping, shutdown on BPOfferService
* objects must be done via APIs in this class.
*/
@InterfaceAudience.Private
class BlockPoolManager {
private static final Log LOG = DataNode.LOG;
private final Map<String, BPOfferService> bpByNameserviceId =
Maps.newHashMap();
private final Map<String, BPOfferService> bpByBlockPoolId =
Maps.newHashMap();
private final List<BPOfferService> offerServices =
Lists.newArrayList();
private final DataNode dn;
//This lock is used only to ensure exclusion of refreshNamenodes
private final Object refreshNamenodesLock = new Object();
BlockPoolManager(DataNode dn) {
this.dn = dn;
}
synchronized void addBlockPool(BPOfferService bpos) {
Preconditions.checkArgument(offerServices.contains(bpos),
"Unknown BPOS: %s", bpos);
if (bpos.getBlockPoolId() == null) {
throw new IllegalArgumentException("Null blockpool id");
}
bpByBlockPoolId.put(bpos.getBlockPoolId(), bpos);
}
/**
* Returns the array of BPOfferService objects.
* Caution: The BPOfferService returned could be shutdown any time.
*/
synchronized BPOfferService[] getAllNamenodeThreads() {
BPOfferService[] bposArray = new BPOfferService[offerServices.size()];
return offerServices.toArray(bposArray);
}
synchronized BPOfferService get(String bpid) {
return bpByBlockPoolId.get(bpid);
}
synchronized void remove(BPOfferService t) {
offerServices.remove(t);
bpByBlockPoolId.remove(t.getBlockPoolId());
boolean removed = false;
for (Iterator<BPOfferService> it = bpByNameserviceId.values().iterator();
it.hasNext() && !removed;) {
BPOfferService bpos = it.next();
if (bpos == t) {
it.remove();
LOG.info("Removed " + bpos);
removed = true;
}
}
if (!removed) {
LOG.warn("Couldn't remove BPOS " + t + " from bpByNameserviceId map");
}
}
void shutDownAll(BPOfferService[] bposArray) throws InterruptedException {
if (bposArray != null) {
for (BPOfferService bpos : bposArray) {
bpos.stop(); //interrupts the threads
}
//now join
for (BPOfferService bpos : bposArray) {
bpos.join();
}
}
}
synchronized void startAll() throws IOException {
try {
UserGroupInformation.getLoginUser().doAs(
new PrivilegedExceptionAction<Object>() {
@Override
public Object run() throws Exception {
for (BPOfferService bpos : offerServices) {
bpos.start();
}
return null;
}
});
} catch (InterruptedException ex) {
IOException ioe = new IOException();
ioe.initCause(ex.getCause());
throw ioe;
}
}
void joinAll() {
for (BPOfferService bpos: this.getAllNamenodeThreads()) {
bpos.join();
}
}
void refreshNamenodes(Configuration conf)
throws IOException {
LOG.info("Refresh request received for nameservices: "
+ conf.get(DFSConfigKeys.DFS_NAMESERVICES));
Map<String, Map<String, InetSocketAddress>> newAddressMap =
DFSUtil.getNNServiceRpcAddresses(conf);
synchronized (refreshNamenodesLock) {
doRefreshNamenodes(newAddressMap);
}
}
private void doRefreshNamenodes(
Map<String, Map<String, InetSocketAddress>> addrMap) throws IOException {
assert Thread.holdsLock(refreshNamenodesLock);
Set<String> toRefresh = Sets.newLinkedHashSet();
Set<String> toAdd = Sets.newLinkedHashSet();
Set<String> toRemove;
synchronized (this) {
// Step 1. For each of the new nameservices, figure out whether
// it's an update of the set of NNs for an existing NS,
// or an entirely new nameservice.
for (String nameserviceId : addrMap.keySet()) {
if (bpByNameserviceId.containsKey(nameserviceId)) {
toRefresh.add(nameserviceId);
} else {
toAdd.add(nameserviceId);
}
}
// Step 2. Any nameservices we currently have but are no longer present
// need to be removed.
toRemove = Sets.newHashSet(Sets.difference(
bpByNameserviceId.keySet(), addrMap.keySet()));
assert toRefresh.size() + toAdd.size() ==
addrMap.size() :
"toAdd: " + Joiner.on(",").useForNull("<default>").join(toAdd) +
" toRemove: " + Joiner.on(",").useForNull("<default>").join(toRemove) +
" toRefresh: " + Joiner.on(",").useForNull("<default>").join(toRefresh);
// Step 3. Start new nameservices
if (!toAdd.isEmpty()) {
LOG.info("Starting BPOfferServices for nameservices: " +
Joiner.on(",").useForNull("<default>").join(toAdd));
for (String nsToAdd : toAdd) {
ArrayList<InetSocketAddress> addrs =
Lists.newArrayList(addrMap.get(nsToAdd).values());
BPOfferService bpos = createBPOS(addrs);
bpByNameserviceId.put(nsToAdd, bpos);
offerServices.add(bpos);
}
}
startAll();
}
// Step 4. Shut down old nameservices. This happens outside
// of the synchronized(this) lock since they need to call
// back to .remove() from another thread
if (!toRemove.isEmpty()) {
LOG.info("Stopping BPOfferServices for nameservices: " +
Joiner.on(",").useForNull("<default>").join(toRemove));
for (String nsToRemove : toRemove) {
BPOfferService bpos = bpByNameserviceId.get(nsToRemove);
bpos.stop();
bpos.join();
// they will call remove on their own
}
}
// Step 5. Update nameservices whose NN list has changed
if (!toRefresh.isEmpty()) {
LOG.info("Refreshing list of NNs for nameservices: " +
Joiner.on(",").useForNull("<default>").join(toRefresh));
for (String nsToRefresh : toRefresh) {
BPOfferService bpos = bpByNameserviceId.get(nsToRefresh);
ArrayList<InetSocketAddress> addrs =
Lists.newArrayList(addrMap.get(nsToRefresh).values());
bpos.refreshNNList(addrs);
}
}
}
/**
* Extracted out for test purposes.
*/
protected BPOfferService createBPOS(List<InetSocketAddress> nnAddrs) {
return new BPOfferService(nnAddrs, dn);
}
}