/// <summary>
/// Test that we can zero-copy read cached data even without disabling
/// checksums.
/// </summary>
/// <exception cref="System.Exception"/>
public virtual void TestZeroCopyReadOfCachedData()
{
BlockReaderTestUtil.EnableShortCircuitShmTracing();
BlockReaderTestUtil.EnableBlockReaderFactoryTracing();
BlockReaderTestUtil.EnableHdfsCachingTracing();
int TestFileLength = BlockSize;
Path TestPath = new Path("/a");
int RandomSeed = 23453;
HdfsConfiguration conf = InitZeroCopyTest();
conf.SetBoolean(DFSConfigKeys.DfsClientReadShortcircuitSkipChecksumKey, false);
string Context = "testZeroCopyReadOfCachedData";
conf.Set(DFSConfigKeys.DfsClientContext, Context);
conf.SetLong(DFSConfigKeys.DfsDatanodeMaxLockedMemoryKey, DFSTestUtil.RoundUpToMultiple
(TestFileLength, (int)NativeIO.POSIX.GetCacheManipulator().GetOperatingSystemPageSize
()));
MiniDFSCluster cluster = null;
ByteBuffer result = null;
ByteBuffer result2 = null;
cluster = new MiniDFSCluster.Builder(conf).NumDataNodes(1).Build();
cluster.WaitActive();
FsDatasetSpi <object> fsd = cluster.GetDataNodes()[0].GetFSDataset();
DistributedFileSystem fs = cluster.GetFileSystem();
DFSTestUtil.CreateFile(fs, TestPath, TestFileLength, (short)1, RandomSeed);
DFSTestUtil.WaitReplication(fs, TestPath, (short)1);
byte[] original = DFSTestUtil.CalculateFileContentsFromSeed(RandomSeed, TestFileLength
);
// Prior to caching, the file can't be read via zero-copy
FSDataInputStream fsIn = fs.Open(TestPath);
try
{
result = fsIn.Read(null, TestFileLength / 2, EnumSet.NoneOf <ReadOption>());
NUnit.Framework.Assert.Fail("expected UnsupportedOperationException");
}
catch (NotSupportedException)
{
}
// expected
// Cache the file
fs.AddCachePool(new CachePoolInfo("pool1"));
long directiveId = fs.AddCacheDirective(new CacheDirectiveInfo.Builder().SetPath(
TestPath).SetReplication((short)1).SetPool("pool1").Build());
int numBlocks = (int)Math.Ceil((double)TestFileLength / BlockSize);
DFSTestUtil.VerifyExpectedCacheUsage(DFSTestUtil.RoundUpToMultiple(TestFileLength
, BlockSize), numBlocks, cluster.GetDataNodes()[0].GetFSDataset());
try
{
result = fsIn.Read(null, TestFileLength, EnumSet.NoneOf <ReadOption>());
}
catch (NotSupportedException)
{
NUnit.Framework.Assert.Fail("expected to be able to read cached file via zero-copy"
);
}
Assert.AssertArrayEquals(Arrays.CopyOfRange(original, 0, BlockSize), ByteBufferToArray
(result));
// Test that files opened after the cache operation has finished
// still get the benefits of zero-copy (regression test for HDFS-6086)
FSDataInputStream fsIn2 = fs.Open(TestPath);
try
{
result2 = fsIn2.Read(null, TestFileLength, EnumSet.NoneOf <ReadOption>());
}
catch (NotSupportedException)
{
NUnit.Framework.Assert.Fail("expected to be able to read cached file via zero-copy"
);
}
Assert.AssertArrayEquals(Arrays.CopyOfRange(original, 0, BlockSize), ByteBufferToArray
(result2));
fsIn2.ReleaseBuffer(result2);
fsIn2.Close();
// check that the replica is anchored
ExtendedBlock firstBlock = DFSTestUtil.GetFirstBlock(fs, TestPath);
ShortCircuitCache cache = ClientContext.Get(Context, new DFSClient.Conf(conf)).GetShortCircuitCache
();
WaitForReplicaAnchorStatus(cache, firstBlock, true, true, 1);
// Uncache the replica
fs.RemoveCacheDirective(directiveId);
WaitForReplicaAnchorStatus(cache, firstBlock, false, true, 1);
fsIn.ReleaseBuffer(result);
WaitForReplicaAnchorStatus(cache, firstBlock, false, false, 1);
DFSTestUtil.VerifyExpectedCacheUsage(0, 0, fsd);
fsIn.Close();
fs.Close();
cluster.Shutdown();
}
