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HDFS-5526. Datanode cannot roll back to previous layout version. Contributed by Kihwal Lee. 

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1545322 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Kihwal Lee 2013-11-25 15:33:52 +00:00
parent 38f94dc16d
commit 65ee88b0de
3 changed files with 76 additions and 29 deletions
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2
hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
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@ -4018,6 +4018,8 @@ Release 0.23.10 - UNRELEASED
HDFS-4329. DFSShell issues with directories with spaces in name (Cristina
L. Abad via jeagles)
HDFS-5526. Datanode cannot roll back to previous layout version (kihwal)
Release 0.23.9 - 2013-07-08
INCOMPATIBLE CHANGES

81
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataStorage.java
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@ -299,7 +299,16 @@ public class DataStorage extends Storage {
@Override
protected void setFieldsFromProperties(Properties props, StorageDirectory sd)
throws IOException {
setLayoutVersion(props, sd);
setFieldsFromProperties(props, sd, false, 0);
}
private void setFieldsFromProperties(Properties props, StorageDirectory sd,
boolean overrideLayoutVersion, int toLayoutVersion) throws IOException {
if (overrideLayoutVersion) {
this.layoutVersion = toLayoutVersion;
} else {
setLayoutVersion(props, sd);
}
setcTime(props, sd);
setStorageType(props, sd);
setClusterId(props, layoutVersion, sd);
@ -347,13 +356,20 @@ public class DataStorage extends Storage {
return true;
}
/** Read VERSION file for rollback */
void readProperties(StorageDirectory sd, int rollbackLayoutVersion)
throws IOException {
Properties props = readPropertiesFile(sd.getVersionFile());
setFieldsFromProperties(props, sd, true, rollbackLayoutVersion);
}
/**
* Analize which and whether a transition of the fs state is required
* and perform it if necessary.
*
* Rollback if previousLV >= LAYOUT_VERSION && prevCTime <= namenode.cTime
* Upgrade if this.LV > LAYOUT_VERSION || this.cTime < namenode.cTime
* Regular startup if this.LV = LAYOUT_VERSION && this.cTime = namenode.cTime
* Rollback if the rollback startup option was specified.
* Upgrade if this.LV > LAYOUT_VERSION
* Regular startup if this.LV = LAYOUT_VERSION
*
* @param datanode Datanode to which this storage belongs to
* @param sd storage directory
@ -393,25 +409,28 @@ public class DataStorage extends Storage {
+ nsInfo.getClusterID() + "; datanode clusterID = " + getClusterID());
}
// regular start up
if (this.layoutVersion == HdfsConstants.LAYOUT_VERSION
&& this.cTime == nsInfo.getCTime())
// After addition of the federation feature, ctime check is only
// meaningful at BlockPoolSliceStorage level.
// regular start up.
if (this.layoutVersion == HdfsConstants.LAYOUT_VERSION)
return; // regular startup
// do upgrade
if (this.layoutVersion > HdfsConstants.LAYOUT_VERSION
|| this.cTime < nsInfo.getCTime()) {
if (this.layoutVersion > HdfsConstants.LAYOUT_VERSION) {
doUpgrade(sd, nsInfo); // upgrade
return;
}
// layoutVersion == LAYOUT_VERSION && this.cTime > nsInfo.cTime
// must shutdown
throw new IOException("Datanode state: LV = " + this.getLayoutVersion()
+ " CTime = " + this.getCTime()
+ " is newer than the namespace state: LV = "
+ nsInfo.getLayoutVersion()
+ " CTime = " + nsInfo.getCTime());
// layoutVersion < LAYOUT_VERSION. I.e. stored layout version is newer
// than the version supported by datanode. This should have been caught
// in readProperties(), even if rollback was not carried out or somehow
// failed.
throw new IOException("BUG: The stored LV = " + this.getLayoutVersion()
+ " is newer than the supported LV = "
+ HdfsConstants.LAYOUT_VERSION
+ " or name node LV = "
+ nsInfo.getLayoutVersion());
}
/**
@ -437,8 +456,13 @@ public class DataStorage extends Storage {
* @throws IOException on error
*/
void doUpgrade(StorageDirectory sd, NamespaceInfo nsInfo) throws IOException {
// If the existing on-disk layout version supportes federation, simply
// update its layout version.
if (LayoutVersion.supports(Feature.FEDERATION, layoutVersion)) {
clusterID = nsInfo.getClusterID();
// The VERSION file is already read in. Override the layoutVersion
// field and overwrite the file.
LOG.info("Updating layout version from " + layoutVersion + " to "
+ nsInfo.getLayoutVersion() + " for storage " + sd.getRoot());
layoutVersion = nsInfo.getLayoutVersion();
writeProperties(sd);
return;
@ -523,15 +547,32 @@ public class DataStorage extends Storage {
* <li> Remove removed.tmp </li>
* </ol>
*
* Do nothing, if previous directory does not exist.
* If previous directory does not exist and the current version supports
* federation, perform a simple rollback of layout version. This does not
* involve saving/restoration of actual data.
*/
void doRollback( StorageDirectory sd,
NamespaceInfo nsInfo
) throws IOException {
File prevDir = sd.getPreviousDir();
// regular startup if previous dir does not exist
if (!prevDir.exists())
// This is a regular startup or a post-federation rollback
if (!prevDir.exists()) {
// The current datanode version supports federation and the layout
// version from namenode matches what the datanode supports. An invalid
// rollback may happen if namenode didn't rollback and datanode is
// running a wrong version. But this will be detected in block pool
// level and the invalid VERSION content will be overwritten when
// the error is corrected and rollback is retried.
if (LayoutVersion.supports(Feature.FEDERATION,
HdfsConstants.LAYOUT_VERSION) &&
HdfsConstants.LAYOUT_VERSION == nsInfo.getLayoutVersion()) {
readProperties(sd, nsInfo.getLayoutVersion());
writeProperties(sd);
LOG.info("Layout version rolled back to " +
nsInfo.getLayoutVersion() + " for storage " + sd.getRoot());
}
return;
}
DataStorage prevInfo = new DataStorage();
prevInfo.readPreviousVersionProperties(sd);

22
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSRollback.java
View File

@ -191,21 +191,25 @@ public class TestDFSRollback {
// Create a previous snapshot for the blockpool
UpgradeUtilities.createBlockPoolStorageDirs(dataNodeDirs, "previous",
UpgradeUtilities.getCurrentBlockPoolID(cluster));
// Older LayoutVersion to make it rollback
// Put newer layout version in current.
storageInfo = new StorageInfo(
UpgradeUtilities.getCurrentLayoutVersion()+1,
UpgradeUtilities.getCurrentLayoutVersion()-1,
UpgradeUtilities.getCurrentNamespaceID(cluster),
UpgradeUtilities.getCurrentClusterID(cluster),
UpgradeUtilities.getCurrentFsscTime(cluster));
// Create old VERSION file for each data dir
// Overwrite VERSION file in the current directory of
// volume directories and block pool slice directories
// with a layout version from future.
File[] dataCurrentDirs = new File[dataNodeDirs.length];
for (int i=0; i<dataNodeDirs.length; i++) {
Path bpPrevPath = new Path(dataNodeDirs[i] + "/current/"
+ UpgradeUtilities.getCurrentBlockPoolID(cluster));
UpgradeUtilities.createBlockPoolVersionFile(
new File(bpPrevPath.toString()),
storageInfo,
UpgradeUtilities.getCurrentBlockPoolID(cluster));
dataCurrentDirs[i] = new File((new Path(dataNodeDirs[i]
+ "/current")).toString());
}
UpgradeUtilities.createDataNodeVersionFile(
dataCurrentDirs,
storageInfo,
UpgradeUtilities.getCurrentBlockPoolID(cluster));
cluster.startDataNodes(conf, 1, false, StartupOption.ROLLBACK, null);
assertTrue(cluster.isDataNodeUp());