Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* 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.hbase.client.example;
import static org.apache.hadoop.hbase.util.FutureUtils.addListener;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicReference;
import java.util.stream.IntStream;
import org.apache.commons.io.IOUtils;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.AsyncConnection;
import org.apache.hadoop.hbase.client.AsyncTable;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.Threads;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hbase.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder;
/**
* A simple example shows how to use asynchronous client.
*/
@InterfaceAudience.Private
public class AsyncClientExample extends Configured implements Tool {
private static final Logger LOG = LoggerFactory.getLogger(AsyncClientExample.class);
/**
* The size for thread pool.
*/
private static final int THREAD_POOL_SIZE = 16;
/**
* The default number of operations.
*/
private static final int DEFAULT_NUM_OPS = 100;
/**
* The name of the column family. d for default.
*/
private static final byte[] FAMILY = Bytes.toBytes("d");
/**
* For the example we're just using one qualifier.
*/
private static final byte[] QUAL = Bytes.toBytes("test");
private final AtomicReference> future =
new AtomicReference<>();
private CompletableFuture getConn() {
CompletableFuture f = future.get();
if (f != null) {
return f;
}
for (;;) {
if (future.compareAndSet(null, new CompletableFuture<>())) {
CompletableFuture toComplete = future.get();
addListener(ConnectionFactory.createAsyncConnection(getConf()), (conn, error) -> {
if (error != null) {
toComplete.completeExceptionally(error);
// we need to reset the future holder so we will get a chance to recreate an async
// connection at next try.
future.set(null);
return;
}
toComplete.complete(conn);
});
return toComplete;
} else {
f = future.get();
if (f != null) {
return f;
}
}
}
}
@edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "NP_NONNULL_PARAM_VIOLATION",
justification = "it is valid to pass NULL to CompletableFuture#completedFuture")
private CompletableFuture closeConn() {
CompletableFuture f = future.get();
if (f == null) {
return CompletableFuture.completedFuture(null);
}
CompletableFuture closeFuture = new CompletableFuture<>();
addListener(f, (conn, error) -> {
if (error == null) {
IOUtils.closeQuietly(conn, e -> LOG.warn("failed to close conn", e));
}
closeFuture.complete(null);
});
return closeFuture;
}
private byte[] getKey(int i) {
return Bytes.toBytes(String.format("%08x", i));
}
@Override
public int run(String[] args) throws Exception {
if (args.length < 1 || args.length > 2) {
System.out.println("Usage: " + this.getClass().getName() + " tableName [num_operations]");
return -1;
}
TableName tableName = TableName.valueOf(args[0]);
int numOps = args.length > 1 ? Integer.parseInt(args[1]) : DEFAULT_NUM_OPS;
ExecutorService threadPool = Executors.newFixedThreadPool(THREAD_POOL_SIZE,
new ThreadFactoryBuilder().setNameFormat("AsyncClientExample-pool-%d").setDaemon(true)
.setUncaughtExceptionHandler(Threads.LOGGING_EXCEPTION_HANDLER).build());
// We use AsyncTable here so we need to provide a separated thread pool. RawAsyncTable does not
// need a thread pool and may have a better performance if you use it correctly as it can save
// some context switches. But if you use RawAsyncTable incorrectly, you may have a very bad
// impact on performance so use it with caution.
CountDownLatch latch = new CountDownLatch(numOps);
IntStream.range(0, numOps).forEach(i -> {
CompletableFuture future = getConn();
addListener(future, (conn, error) -> {
if (error != null) {
LOG.warn("failed to get async connection for " + i, error);
latch.countDown();
return;
}
AsyncTable table = conn.getTable(tableName, threadPool);
addListener(table.put(new Put(getKey(i)).addColumn(FAMILY, QUAL, Bytes.toBytes(i))),
(putResp, putErr) -> {
if (putErr != null) {
LOG.warn("put failed for " + i, putErr);
latch.countDown();
return;
}
LOG.info("put for " + i + " succeeded, try getting");
addListener(table.get(new Get(getKey(i))), (result, getErr) -> {
if (getErr != null) {
LOG.warn("get failed for " + i);
latch.countDown();
return;
}
if (result.isEmpty()) {
LOG.warn("get failed for " + i + ", server returns empty result");
} else if (!result.containsColumn(FAMILY, QUAL)) {
LOG.warn("get failed for " + i + ", the result does not contain "
+ Bytes.toString(FAMILY) + ":" + Bytes.toString(QUAL));
} else {
int v = Bytes.toInt(result.getValue(FAMILY, QUAL));
if (v != i) {
LOG.warn("get failed for " + i + ", the value of " + Bytes.toString(FAMILY) + ":"
+ Bytes.toString(QUAL) + " is " + v + ", exected " + i);
} else {
LOG.info("get for " + i + " succeeded");
}
}
latch.countDown();
});
});
});
});
latch.await();
closeConn().get();
return 0;
}
public static void main(String[] args) throws Exception {
ToolRunner.run(new AsyncClientExample(), args);
}
}
