public virtual void TestRestartDFS()
{
Configuration conf = new HdfsConfiguration();
MiniDFSCluster cluster = null;
FSNamesystem fsn = null;
int numNamenodeDirs;
DFSTestUtil files = new DFSTestUtil.Builder().SetName("TestRestartDFS").SetNumFiles
(200).Build();
string dir = "/srcdat";
Path rootpath = new Path("/");
Path dirpath = new Path(dir);
long rootmtime;
FileStatus rootstatus;
FileStatus dirstatus;
try
{
cluster = new MiniDFSCluster.Builder(conf).Format(true).NumDataNodes(NumDatanodes
).Build();
string[] nameNodeDirs = conf.GetStrings(DFSConfigKeys.DfsNamenodeNameDirKey, new
string[] { });
numNamenodeDirs = nameNodeDirs.Length;
NUnit.Framework.Assert.IsTrue("failed to get number of Namenode StorageDirs", numNamenodeDirs
!= 0);
FileSystem fs = cluster.GetFileSystem();
files.CreateFiles(fs, dir);
rootmtime = fs.GetFileStatus(rootpath).GetModificationTime();
rootstatus = fs.GetFileStatus(dirpath);
dirstatus = fs.GetFileStatus(dirpath);
fs.SetOwner(rootpath, rootstatus.GetOwner() + "_XXX", null);
fs.SetOwner(dirpath, null, dirstatus.GetGroup() + "_XXX");
}
finally
{
if (cluster != null)
{
cluster.Shutdown();
}
}
try
{
// Force the NN to save its images on startup so long as
// there are any uncheckpointed txns
conf.SetInt(DFSConfigKeys.DfsNamenodeCheckpointTxnsKey, 1);
// Here we restart the MiniDFScluster without formatting namenode
cluster = new MiniDFSCluster.Builder(conf).Format(false).NumDataNodes(NumDatanodes
).Build();
fsn = cluster.GetNamesystem();
FileSystem fs = cluster.GetFileSystem();
NUnit.Framework.Assert.IsTrue("Filesystem corrupted after restart.", files.CheckFiles
(fs, dir));
FileStatus newrootstatus = fs.GetFileStatus(rootpath);
NUnit.Framework.Assert.AreEqual(rootmtime, newrootstatus.GetModificationTime());
NUnit.Framework.Assert.AreEqual(rootstatus.GetOwner() + "_XXX", newrootstatus.GetOwner
());
NUnit.Framework.Assert.AreEqual(rootstatus.GetGroup(), newrootstatus.GetGroup());
FileStatus newdirstatus = fs.GetFileStatus(dirpath);
NUnit.Framework.Assert.AreEqual(dirstatus.GetOwner(), newdirstatus.GetOwner());
NUnit.Framework.Assert.AreEqual(dirstatus.GetGroup() + "_XXX", newdirstatus.GetGroup
());
rootmtime = fs.GetFileStatus(rootpath).GetModificationTime();
string checkAfterRestart = CheckImages(fsn, numNamenodeDirs);
// Modify the system and then perform saveNamespace
files.Cleanup(fs, dir);
files.CreateFiles(fs, dir);
fsn.SetSafeMode(HdfsConstants.SafeModeAction.SafemodeEnter);
cluster.GetNameNodeRpc().SaveNamespace();
string checkAfterModify = CheckImages(fsn, numNamenodeDirs);
NUnit.Framework.Assert.IsFalse("Modified namespace should change fsimage contents. "
+ "was: " + checkAfterRestart + " now: " + checkAfterModify, checkAfterRestart.
Equals(checkAfterModify));
fsn.SetSafeMode(HdfsConstants.SafeModeAction.SafemodeLeave);
files.Cleanup(fs, dir);
}
finally
{
if (cluster != null)
{
cluster.Shutdown();
}
}
}
