package org.apache.hadoop.hbase.regionserver;
import static org.junit.Assert.assertEquals;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.SmallTests;
import org.apache.hadoop.hbase.MultithreadedTestUtil;
import org.apache.hadoop.hbase.MultithreadedTestUtil.TestContext;
import org.apache.hadoop.hbase.MultithreadedTestUtil.TestThread;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.BinaryComparator;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.io.HeapSize;
import org.apache.hadoop.hbase.regionserver.wal.HLog;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.Pair;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import com.google.common.collect.Lists;
/**
* Test of HBASE-7051; that checkAndPuts and puts behave atomically with respect to each other.
* Rather than perform a bunch of trials to verify atomicity, this test recreates a race condition
* that causes the test to fail if checkAndPut doesn't wait for outstanding put transactions
* to complete. It does this by invasively overriding HRegion function to affect the timing of
* the operations.
*/
@Category(SmallTests.class)
public class TestHBase7051 {
private static CountDownLatch latch = new CountDownLatch(1);
private enum TestStep {
INIT, // initial put of 10 to set value of the cell
PUT_STARTED, // began doing a put of 50 to cell
PUT_COMPLETED, // put complete (released RowLock, but may not have advanced MVCC).
CHECKANDPUT_STARTED, // began checkAndPut: if 10 -> 11
CHECKANDPUT_COMPLETED // completed checkAndPut
// NOTE: at the end of these steps, the value of the cell should be 50, not 11!
}
private static volatile TestStep testStep = TestStep.INIT;
private final String family = "f1";
@Test
public void testPutAndCheckAndPutInParallel() throws Exception {
final String tableName = "testPutAndCheckAndPut";
Configuration conf = HBaseConfiguration.create();
conf.setClass(HConstants.REGION_IMPL, MockHRegion.class, HeapSize.class);
final MockHRegion region = (MockHRegion) TestHRegion.initHRegion(Bytes.toBytes(tableName),
tableName, conf, Bytes.toBytes(family));
List<Pair<Mutation, Integer>> putsAndLocks = Lists.newArrayList();
Put[] puts = new Put[1];
Put put = new Put(Bytes.toBytes("r1"));
put.add(Bytes.toBytes(family), Bytes.toBytes("q1"), Bytes.toBytes("10"));
puts[0] = put;
Pair<Mutation, Integer> pair = new Pair<Mutation, Integer>(puts[0], null);
putsAndLocks.add(pair);
region.batchMutate(putsAndLocks.toArray(new Pair[0]));
MultithreadedTestUtil.TestContext ctx =
new MultithreadedTestUtil.TestContext(conf);
ctx.addThread(new PutThread(ctx, region));
ctx.addThread(new CheckAndPutThread(ctx, region));
ctx.startThreads();
while (testStep != TestStep.CHECKANDPUT_COMPLETED) {
Thread.sleep(100);
}
ctx.stop();
Scan s = new Scan();
RegionScanner scanner = region.getScanner(s);
List<KeyValue> results = new ArrayList<KeyValue>();
scanner.next(results, 2);
for (KeyValue keyValue : results) {
assertEquals("50",Bytes.toString(keyValue.getValue()));
}
}
private class PutThread extends TestThread {
private MockHRegion region;
PutThread(TestContext ctx, MockHRegion region) {
super(ctx);
this.region = region;
}
public void doWork() throws Exception {
List<Pair<Mutation, Integer>> putsAndLocks = Lists.newArrayList();
Put[] puts = new Put[1];
Put put = new Put(Bytes.toBytes("r1"));
put.add(Bytes.toBytes(family), Bytes.toBytes("q1"), Bytes.toBytes("50"));
puts[0] = put;
Pair<Mutation, Integer> pair = new Pair<Mutation, Integer>(puts[0], null);
putsAndLocks.add(pair);
testStep = TestStep.PUT_STARTED;
region.batchMutate(putsAndLocks.toArray(new Pair[0]));
}
}
private class CheckAndPutThread extends TestThread {
private MockHRegion region;
CheckAndPutThread(TestContext ctx, MockHRegion region) {
super(ctx);
this.region = region;
}
public void doWork() throws Exception {
Put[] puts = new Put[1];
Put put = new Put(Bytes.toBytes("r1"));
put.add(Bytes.toBytes(family), Bytes.toBytes("q1"), Bytes.toBytes("11"));
puts[0] = put;
while (testStep != TestStep.PUT_COMPLETED) {
Thread.sleep(100);
}
testStep = TestStep.CHECKANDPUT_STARTED;
region.checkAndMutate(Bytes.toBytes("r1"), Bytes.toBytes(family), Bytes.toBytes("q1"),
CompareOp.EQUAL, new BinaryComparator(Bytes.toBytes("10")), put, true);
testStep = TestStep.CHECKANDPUT_COMPLETED;
}
}
public static class MockHRegion extends HRegion {
public MockHRegion(Path tableDir, HLog log, FileSystem fs, Configuration conf,
final HRegionInfo regionInfo, final HTableDescriptor htd, RegionServerServices rsServices) {
super(tableDir, log, fs, conf, regionInfo, htd, rsServices);
}
@Override
public void releaseRowLock(Integer lockId) {
if (testStep == TestStep.INIT) {
super.releaseRowLock(lockId);
return;
}
if (testStep == TestStep.PUT_STARTED) {
try {
testStep = TestStep.PUT_COMPLETED;
super.releaseRowLock(lockId);
// put has been written to the memstore and the row lock has been released, but the
// MVCC has not been advanced. Prior to fixing HBASE-7051, the following order of
// operations would cause the non-atomicity to show up:
// 1) Put releases row lock (where we are now)
// 2) CheckAndPut grabs row lock and reads the value prior to the put (10)
// because the MVCC has not advanced
// 3) Put advances MVCC
// So, in order to recreate this order, we wait for the checkAndPut to grab the rowLock
// (see below), and then wait some more to give the checkAndPut time to read the old
// value.
latch.await();
Thread.sleep(1000);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
else if (testStep == TestStep.CHECKANDPUT_STARTED) {
super.releaseRowLock(lockId);
}
}
@Override
public Integer getLock(Integer lockid, byte[] row, boolean waitForLock) throws IOException {
if (testStep == TestStep.CHECKANDPUT_STARTED) {
latch.countDown();
}
return super.getLock(lockid, row, waitForLock);
}
}
}