/*
* 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.accumulo.server.master.state;
import static java.nio.charset.StandardCharsets.UTF_8;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.accumulo.core.metadata.RootTable;
import org.apache.accumulo.core.tabletserver.log.LogEntry;
import org.apache.commons.lang.NotImplementedException;
import org.apache.hadoop.fs.Path;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.net.HostAndPort;
public class ZooTabletStateStore extends TabletStateStore {
private static final Logger log = LoggerFactory.getLogger(ZooTabletStateStore.class);
final private DistributedStore store;
public ZooTabletStateStore(DistributedStore store) {
this.store = store;
}
public ZooTabletStateStore() throws DistributedStoreException {
try {
store = new ZooStore();
} catch (IOException ex) {
throw new DistributedStoreException(ex);
}
}
@Override
public ClosableIterator<TabletLocationState> iterator() {
return new ClosableIterator<TabletLocationState>() {
boolean finished = false;
@Override
public boolean hasNext() {
return !finished;
}
@Override
public TabletLocationState next() {
finished = true;
try {
byte[] future = store.get(RootTable.ZROOT_TABLET_FUTURE_LOCATION);
byte[] current = store.get(RootTable.ZROOT_TABLET_LOCATION);
byte[] last = store.get(RootTable.ZROOT_TABLET_LAST_LOCATION);
TServerInstance currentSession = null;
TServerInstance futureSession = null;
TServerInstance lastSession = null;
if (future != null)
futureSession = parse(future);
if (last != null)
lastSession = parse(last);
if (current != null) {
currentSession = parse(current);
futureSession = null;
}
List<Collection<String>> logs = new ArrayList<>();
for (String entry : store.getChildren(RootTable.ZROOT_TABLET_WALOGS)) {
byte[] logInfo = store.get(RootTable.ZROOT_TABLET_WALOGS + "/" + entry);
if (logInfo != null) {
LogEntry logEntry = LogEntry.fromBytes(logInfo);
logs.add(Collections.singleton(logEntry.filename));
log.debug("root tablet log " + logEntry.filename);
}
}
TabletLocationState result = new TabletLocationState(RootTable.EXTENT, futureSession, currentSession, lastSession, null, logs, false);
log.debug("Returning root tablet state: " + result);
return result;
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
@Override
public void remove() {
throw new NotImplementedException();
}
@Override
public void close() {}
};
}
protected TServerInstance parse(byte[] current) {
String str = new String(current, UTF_8);
String[] parts = str.split("[|]", 2);
HostAndPort address = HostAndPort.fromString(parts[0]);
if (parts.length > 1 && parts[1] != null && parts[1].length() > 0) {
return new TServerInstance(address, parts[1]);
} else {
// a 1.2 location specification: DO NOT WANT
return null;
}
}
@Override
public void setFutureLocations(Collection<Assignment> assignments) throws DistributedStoreException {
if (assignments.size() != 1)
throw new IllegalArgumentException("There is only one root tablet");
Assignment assignment = assignments.iterator().next();
if (assignment.tablet.compareTo(RootTable.EXTENT) != 0)
throw new IllegalArgumentException("You can only store the root tablet location");
String value = assignment.server.getLocation() + "|" + assignment.server.getSession();
Iterator<TabletLocationState> currentIter = iterator();
TabletLocationState current = currentIter.next();
if (current.current != null) {
throw new DistributedStoreException("Trying to set the root tablet location: it is already set to " + current.current);
}
store.put(RootTable.ZROOT_TABLET_FUTURE_LOCATION, value.getBytes(UTF_8));
}
@Override
public void setLocations(Collection<Assignment> assignments) throws DistributedStoreException {
if (assignments.size() != 1)
throw new IllegalArgumentException("There is only one root tablet");
Assignment assignment = assignments.iterator().next();
if (assignment.tablet.compareTo(RootTable.EXTENT) != 0)
throw new IllegalArgumentException("You can only store the root tablet location");
String value = assignment.server.getLocation() + "|" + assignment.server.getSession();
Iterator<TabletLocationState> currentIter = iterator();
TabletLocationState current = currentIter.next();
if (current.current != null) {
throw new DistributedStoreException("Trying to set the root tablet location: it is already set to " + current.current);
}
if (!current.future.equals(assignment.server)) {
throw new DistributedStoreException("Root tablet is already assigned to " + current.future);
}
store.put(RootTable.ZROOT_TABLET_LOCATION, value.getBytes(UTF_8));
store.put(RootTable.ZROOT_TABLET_LAST_LOCATION, value.getBytes(UTF_8));
// Make the following unnecessary by making the entire update atomic
store.remove(RootTable.ZROOT_TABLET_FUTURE_LOCATION);
log.debug("Put down root tablet location");
}
@Override
public void unassign(Collection<TabletLocationState> tablets, Map<TServerInstance,List<Path>> logsForDeadServers) throws DistributedStoreException {
if (tablets.size() != 1)
throw new IllegalArgumentException("There is only one root tablet");
TabletLocationState tls = tablets.iterator().next();
if (tls.extent.compareTo(RootTable.EXTENT) != 0)
throw new IllegalArgumentException("You can only store the root tablet location");
if (logsForDeadServers != null) {
List<Path> logs = logsForDeadServers.get(tls.futureOrCurrent());
if (logs != null) {
for (Path entry : logs) {
LogEntry logEntry = new LogEntry(RootTable.EXTENT, System.currentTimeMillis(), tls.futureOrCurrent().getLocation().toString(), entry.toString());
byte[] value;
try {
value = logEntry.toBytes();
} catch (IOException ex) {
throw new DistributedStoreException(ex);
}
store.put(RootTable.ZROOT_TABLET_WALOGS + "/" + logEntry.getUniqueID(), value);
}
}
}
store.remove(RootTable.ZROOT_TABLET_LOCATION);
store.remove(RootTable.ZROOT_TABLET_FUTURE_LOCATION);
log.debug("unassign root tablet location");
}
@Override
public void suspend(Collection<TabletLocationState> tablets, Map<TServerInstance,List<Path>> logsForDeadServers, long suspensionTimestamp)
throws DistributedStoreException {
// No support for suspending root tablet.
unassign(tablets, logsForDeadServers);
}
@Override
public void unsuspend(Collection<TabletLocationState> tablets) throws DistributedStoreException {
// no support for suspending root tablet.
}
@Override
public String name() {
return "Root Table";
}
}