io.shardingsphere.jdbc.orchestration.reg.zookeeper.ZookeeperRegistryCenter Maven / Gradle / Ivy
/*
* Copyright 2016-2018 shardingsphere.io.
*
* Licensed 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 io.shardingsphere.jdbc.orchestration.reg.zookeeper;
import com.google.common.base.Charsets;
import com.google.common.base.Strings;
import io.shardingsphere.jdbc.orchestration.reg.api.RegistryCenter;
import io.shardingsphere.jdbc.orchestration.reg.exception.RegExceptionHandler;
import io.shardingsphere.jdbc.orchestration.reg.listener.DataChangedEvent;
import io.shardingsphere.jdbc.orchestration.reg.listener.EventListener;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.api.ACLProvider;
import org.apache.curator.framework.recipes.cache.ChildData;
import org.apache.curator.framework.recipes.cache.TreeCache;
import org.apache.curator.framework.recipes.cache.TreeCacheEvent;
import org.apache.curator.framework.recipes.cache.TreeCacheListener;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.curator.utils.CloseableUtils;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException.OperationTimeoutException;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.data.ACL;
import java.io.UnsupportedEncodingException;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.TimeUnit;
/**
* Zookeeper based registry center.
*
* @author zhangliang
*/
public final class ZookeeperRegistryCenter implements RegistryCenter {
private final CuratorFramework client;
private final Map caches = new HashMap<>();
public ZookeeperRegistryCenter(final ZookeeperConfiguration zkConfig) {
client = buildCuratorClient(zkConfig);
initCuratorClient(zkConfig);
}
private CuratorFramework buildCuratorClient(final ZookeeperConfiguration zkConfig) {
CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder()
.connectString(zkConfig.getServerLists())
.retryPolicy(new ExponentialBackoffRetry(zkConfig.getBaseSleepTimeMilliseconds(), zkConfig.getMaxRetries(), zkConfig.getMaxSleepTimeMilliseconds()))
.namespace(zkConfig.getNamespace());
if (0 != zkConfig.getSessionTimeoutMilliseconds()) {
builder.sessionTimeoutMs(zkConfig.getSessionTimeoutMilliseconds());
}
if (0 != zkConfig.getConnectionTimeoutMilliseconds()) {
builder.connectionTimeoutMs(zkConfig.getConnectionTimeoutMilliseconds());
}
if (!Strings.isNullOrEmpty(zkConfig.getDigest())) {
builder.authorization("digest", zkConfig.getDigest().getBytes(Charsets.UTF_8))
.aclProvider(new ACLProvider() {
@Override
public List getDefaultAcl() {
return ZooDefs.Ids.CREATOR_ALL_ACL;
}
@Override
public List getAclForPath(final String path) {
return ZooDefs.Ids.CREATOR_ALL_ACL;
}
});
}
return builder.build();
}
private void initCuratorClient(final ZookeeperConfiguration zkConfig) {
client.start();
try {
if (!client.blockUntilConnected(zkConfig.getMaxSleepTimeMilliseconds() * zkConfig.getMaxRetries(), TimeUnit.MILLISECONDS)) {
client.close();
throw new OperationTimeoutException();
}
} catch (final InterruptedException | OperationTimeoutException ex) {
RegExceptionHandler.handleException(ex);
}
}
@Override
public String get(final String key) {
TreeCache cache = findTreeCache(key);
if (null == cache) {
return getDirectly(key);
}
ChildData resultInCache = cache.getCurrentData(key);
if (null != resultInCache) {
return null == resultInCache.getData() ? null : new String(resultInCache.getData(), Charsets.UTF_8);
}
return getDirectly(key);
}
private TreeCache findTreeCache(final String key) {
for (Entry entry : caches.entrySet()) {
if (key.startsWith(entry.getKey())) {
return entry.getValue();
}
}
return null;
}
@Override
public String getDirectly(final String key) {
try {
return new String(client.getData().forPath(key), Charsets.UTF_8);
// CHECKSTYLE:OFF
} catch (final Exception ex) {
// CHECKSTYLE:ON
RegExceptionHandler.handleException(ex);
return null;
}
}
@Override
public boolean isExisted(final String key) {
try {
return null != client.checkExists().forPath(key);
// CHECKSTYLE:OFF
} catch (final Exception ex) {
// CHECKSTYLE:ON
RegExceptionHandler.handleException(ex);
return false;
}
}
@Override
public List getChildrenKeys(final String key) {
try {
List result = client.getChildren().forPath(key);
Collections.sort(result, new Comparator() {
@Override
public int compare(final String o1, final String o2) {
return o2.compareTo(o1);
}
});
return result;
// CHECKSTYLE:OFF
} catch (final Exception ex) {
// CHECKSTYLE:ON
RegExceptionHandler.handleException(ex);
return Collections.emptyList();
}
}
@Override
public void persist(final String key, final String value) {
try {
if (!isExisted(key)) {
client.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath(key, value.getBytes(Charsets.UTF_8));
} else {
update(key, value);
}
// CHECKSTYLE:OFF
} catch (final Exception ex) {
// CHECKSTYLE:ON
RegExceptionHandler.handleException(ex);
}
}
@Override
public void update(final String key, final String value) {
try {
client.inTransaction().check().forPath(key).and().setData().forPath(key, value.getBytes(Charsets.UTF_8)).and().commit();
// CHECKSTYLE:OFF
} catch (final Exception ex) {
// CHECKSTYLE:ON
RegExceptionHandler.handleException(ex);
}
}
@Override
public void persistEphemeral(final String key, final String value) {
try {
if (isExisted(key)) {
client.delete().deletingChildrenIfNeeded().forPath(key);
}
client.create().creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL).forPath(key, value.getBytes(Charsets.UTF_8));
// CHECKSTYLE:OFF
} catch (final Exception ex) {
// CHECKSTYLE:ON
RegExceptionHandler.handleException(ex);
}
}
@Override
public void watch(final String key, final EventListener eventListener) {
final String path = key + "/";
if (!caches.containsKey(path)) {
addCacheData(key);
}
TreeCache cache = caches.get(path);
cache.getListenable().addListener(new TreeCacheListener() {
@Override
public void childEvent(final CuratorFramework client, final TreeCacheEvent event) throws UnsupportedEncodingException {
ChildData data = event.getData();
if (null == data || null == data.getPath()) {
return;
}
eventListener.onChange(new DataChangedEvent(getEventType(event), data.getPath(), null == data.getData() ? null : new String(data.getData(), "UTF-8")));
}
private DataChangedEvent.Type getEventType(final TreeCacheEvent event) {
switch (event.getType()) {
case NODE_UPDATED:
return DataChangedEvent.Type.UPDATED;
case NODE_REMOVED:
return DataChangedEvent.Type.DELETED;
default:
return DataChangedEvent.Type.IGNORED;
}
}
});
}
private void addCacheData(final String cachePath) {
TreeCache cache = new TreeCache(client, cachePath);
try {
cache.start();
// CHECKSTYLE:OFF
} catch (final Exception ex) {
// CHECKSTYLE:ON
RegExceptionHandler.handleException(ex);
}
caches.put(cachePath + "/", cache);
}
@Override
public void close() {
for (Entry each : caches.entrySet()) {
each.getValue().close();
}
waitForCacheClose();
CloseableUtils.closeQuietly(client);
}
/* TODO 等待500ms, cache先关闭再关闭client, 否则会抛异常
* 因为异步处理, 可能会导致client先关闭而cache还未关闭结束.
* 等待Curator新版本解决这个bug.
* BUG地址：https://issues.apache.org/jira/browse/CURATOR-157
*/
private void waitForCacheClose() {
try {
Thread.sleep(500L);
} catch (final InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
}