public virtual void TestMaxOutHedgedReadPool()
{
isHedgedRead = true;
Configuration conf = new Configuration();
int numHedgedReadPoolThreads = 5;
int initialHedgedReadTimeoutMillis = 50000;
int fixedSleepIntervalMillis = 50;
conf.SetInt(DFSConfigKeys.DfsDfsclientHedgedReadThreadpoolSize, numHedgedReadPoolThreads
);
conf.SetLong(DFSConfigKeys.DfsDfsclientHedgedReadThresholdMillis, initialHedgedReadTimeoutMillis
);
// Set up the InjectionHandler
DFSClientFaultInjector.instance = Org.Mockito.Mockito.Mock <DFSClientFaultInjector
>();
DFSClientFaultInjector injector = DFSClientFaultInjector.instance;
// make preads sleep for 50ms
Org.Mockito.Mockito.DoAnswer(new _Answer_372(fixedSleepIntervalMillis)).When(injector
).StartFetchFromDatanode();
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).NumDataNodes(3).Format(
true).Build();
DistributedFileSystem fileSys = cluster.GetFileSystem();
DFSClient dfsClient = fileSys.GetClient();
DFSHedgedReadMetrics metrics = dfsClient.GetHedgedReadMetrics();
// Metrics instance is static, so we need to reset counts from prior tests.
metrics.hedgedReadOps.Set(0);
metrics.hedgedReadOpsWin.Set(0);
metrics.hedgedReadOpsInCurThread.Set(0);
try
{
Path file1 = new Path("hedgedReadMaxOut.dat");
WriteFile(fileSys, file1);
// Basic test. Reads complete within timeout. Assert that there were no
// hedged reads.
PReadFile(fileSys, file1);
// assert that there were no hedged reads. 50ms + delta < 500ms
NUnit.Framework.Assert.IsTrue(metrics.GetHedgedReadOps() == 0);
NUnit.Framework.Assert.IsTrue(metrics.GetHedgedReadOpsInCurThread() == 0);
/*
* Reads take longer than timeout. But, only one thread reading. Assert
* that there were hedged reads. But, none of the reads had to run in the
* current thread.
*/
dfsClient.SetHedgedReadTimeout(50);
// 50ms
PReadFile(fileSys, file1);
// assert that there were hedged reads
NUnit.Framework.Assert.IsTrue(metrics.GetHedgedReadOps() > 0);
NUnit.Framework.Assert.IsTrue(metrics.GetHedgedReadOpsInCurThread() == 0);
/*
* Multiple threads reading. Reads take longer than timeout. Assert that
* there were hedged reads. And that reads had to run in the current
* thread.
*/
int factor = 10;
int numHedgedReads = numHedgedReadPoolThreads * factor;
long initialReadOpsValue = metrics.GetHedgedReadOps();
ExecutorService executor = Executors.NewFixedThreadPool(numHedgedReads);
AList <Future <Void> > futures = new AList <Future <Void> >();
for (int i = 0; i < numHedgedReads; i++)
{
futures.AddItem(executor.Submit(GetPReadFileCallable(fileSys, file1)));
}
for (int i_1 = 0; i_1 < numHedgedReads; i_1++)
{
futures[i_1].Get();
}
NUnit.Framework.Assert.IsTrue(metrics.GetHedgedReadOps() > initialReadOpsValue);
NUnit.Framework.Assert.IsTrue(metrics.GetHedgedReadOpsInCurThread() > 0);
CleanupFile(fileSys, file1);
executor.Shutdown();
}
finally
{
fileSys.Close();
cluster.Shutdown();
Org.Mockito.Mockito.Reset(injector);
}
}
