/**
* Delete the specified snapshot
*
* @param snapshot
* @throws SnapshotDoesNotExistException If the specified snapshot does not exist.
* @throws IOException For filesystem IOExceptions
*/
public void deleteSnapshot(SnapshotDescription snapshot)
throws SnapshotDoesNotExistException, IOException {
// check to see if it is completed
if (!isSnapshotCompleted(snapshot)) {
throw new SnapshotDoesNotExistException(ProtobufUtil.createSnapshotDesc(snapshot));
}
String snapshotName = snapshot.getName();
// first create the snapshot description and check to see if it exists
FileSystem fs = master.getMasterFileSystem().getFileSystem();
Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, rootDir);
// Get snapshot info from file system. The one passed as parameter is a "fake" snapshotInfo with
// just the "name" and it does not contains the "real" snapshot information
snapshot = SnapshotDescriptionUtils.readSnapshotInfo(fs, snapshotDir);
// call coproc pre hook
MasterCoprocessorHost cpHost = master.getMasterCoprocessorHost();
if (cpHost != null) {
cpHost.preDeleteSnapshot(snapshot);
}
LOG.debug("Deleting snapshot: " + snapshotName);
// delete the existing snapshot
if (!fs.delete(snapshotDir, true)) {
throw new HBaseSnapshotException("Failed to delete snapshot directory: " + snapshotDir);
}
// call coproc post hook
if (cpHost != null) {
cpHost.postDeleteSnapshot(snapshot);
}
}
/**
* @param snapshot descriptor of the snapshot to take
* @param masterServices master services provider
*/
public TakeSnapshotHandler(SnapshotDescription snapshot, final MasterServices masterServices) {
super(masterServices, EventType.C_M_SNAPSHOT_TABLE);
assert snapshot != null : "SnapshotDescription must not be nul1";
assert masterServices != null : "MasterServices must not be nul1";
this.master = masterServices;
this.snapshot = snapshot;
this.snapshotTable = TableName.valueOf(snapshot.getTable());
this.conf = this.master.getConfiguration();
this.fs = this.master.getMasterFileSystem().getFileSystem();
this.rootDir = this.master.getMasterFileSystem().getRootDir();
this.snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshot, rootDir);
this.workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, rootDir);
this.monitor = new ForeignExceptionDispatcher(snapshot.getName());
this.snapshotManifest = SnapshotManifest.create(conf, fs, workingDir, snapshot, monitor);
this.tableLockManager = master.getTableLockManager();
this.tableLock =
this.tableLockManager.writeLock(snapshotTable, EventType.C_M_SNAPSHOT_TABLE.toString());
// prepare the verify
this.verifier = new MasterSnapshotVerifier(masterServices, snapshot, rootDir);
// update the running tasks
this.status =
TaskMonitor.get()
.createStatus("Taking " + snapshot.getType() + " snapshot on table: " + snapshotTable);
}
/**
* Take a snapshot using the specified handler. On failure the snapshot temporary working
* directory is removed. NOTE: prepareToTakeSnapshot() called before this one takes care of the
* rejecting the snapshot request if the table is busy with another snapshot/restore operation.
*
* @param snapshot the snapshot description
* @param handler the snapshot handler
*/
private synchronized void snapshotTable(
SnapshotDescription snapshot, final TakeSnapshotHandler handler)
throws HBaseSnapshotException {
try {
handler.prepare();
this.executorService.submit(handler);
this.snapshotHandlers.put(TableName.valueOf(snapshot.getTable()), handler);
} catch (Exception e) {
// cleanup the working directory by trying to delete it from the fs.
Path workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, rootDir);
try {
if (!this.master.getMasterFileSystem().getFileSystem().delete(workingDir, true)) {
LOG.error(
"Couldn't delete working directory ("
+ workingDir
+ " for snapshot:"
+ ClientSnapshotDescriptionUtils.toString(snapshot));
}
} catch (IOException e1) {
LOG.error(
"Couldn't delete working directory ("
+ workingDir
+ " for snapshot:"
+ ClientSnapshotDescriptionUtils.toString(snapshot));
}
// fail the snapshot
throw new SnapshotCreationException(
"Could not build snapshot handler", e, ProtobufUtil.createSnapshotDesc(snapshot));
}
}
/**
* Create a snapshot timer for the master which notifies the monitor when an error occurs
*
* @param snapshot snapshot to monitor
* @param conf configuration to use when getting the max snapshot life
* @param monitor monitor to notify when the snapshot life expires
* @return the timer to use update to signal the start and end of the snapshot
*/
private TimeoutExceptionInjector getMasterTimerAndBindToMonitor(
SnapshotDescription snapshot, Configuration conf, ForeignExceptionListener monitor) {
long maxTime =
SnapshotDescriptionUtils.getMaxMasterTimeout(
conf, snapshot.getType(), SnapshotDescriptionUtils.DEFAULT_MAX_WAIT_TIME);
return new TimeoutExceptionInjector(monitor, maxTime);
}
/**
* Cleans up any snapshots in the snapshot/.tmp directory that were left from failed snapshot
* attempts.
*
* @throws IOException if we can't reach the filesystem
*/
void resetTempDir() throws IOException {
// cleanup any existing snapshots.
Path tmpdir = SnapshotDescriptionUtils.getWorkingSnapshotDir(rootDir);
if (master.getMasterFileSystem().getFileSystem().exists(tmpdir)) {
if (!master.getMasterFileSystem().getFileSystem().delete(tmpdir, true)) {
LOG.warn("Couldn't delete working snapshot directory: " + tmpdir);
}
}
}
/**
* Gets the list of all completed snapshots.
*
* @param snapshotDir snapshot directory
* @return list of SnapshotDescriptions
* @throws IOException File system exception
*/
private List<SnapshotDescription> getCompletedSnapshots(Path snapshotDir) throws IOException {
List<SnapshotDescription> snapshotDescs = new ArrayList<SnapshotDescription>();
// first create the snapshot root path and check to see if it exists
FileSystem fs = master.getMasterFileSystem().getFileSystem();
if (snapshotDir == null) snapshotDir = SnapshotDescriptionUtils.getSnapshotsDir(rootDir);
// if there are no snapshots, return an empty list
if (!fs.exists(snapshotDir)) {
return snapshotDescs;
}
// ignore all the snapshots in progress
FileStatus[] snapshots =
fs.listStatus(
snapshotDir, new SnapshotDescriptionUtils.CompletedSnaphotDirectoriesFilter(fs));
MasterCoprocessorHost cpHost = master.getMasterCoprocessorHost();
// loop through all the completed snapshots
for (FileStatus snapshot : snapshots) {
Path info = new Path(snapshot.getPath(), SnapshotDescriptionUtils.SNAPSHOTINFO_FILE);
// if the snapshot is bad
if (!fs.exists(info)) {
LOG.error("Snapshot information for " + snapshot.getPath() + " doesn't exist");
continue;
}
FSDataInputStream in = null;
try {
in = fs.open(info);
SnapshotDescription desc = SnapshotDescription.parseFrom(in);
if (cpHost != null) {
try {
cpHost.preListSnapshot(desc);
} catch (AccessDeniedException e) {
LOG.warn(
"Current user does not have access to "
+ desc.getName()
+ " snapshot. "
+ "Either you should be owner of this snapshot or admin user.");
// Skip this and try for next snapshot
continue;
}
}
snapshotDescs.add(desc);
// call coproc post hook
if (cpHost != null) {
cpHost.postListSnapshot(desc);
}
} catch (IOException e) {
LOG.warn("Found a corrupted snapshot " + snapshot.getPath(), e);
} finally {
if (in != null) {
in.close();
}
}
}
return snapshotDescs;
}
/**
* Check to see if the snapshot is one of the currently completed snapshots Returns true if the
* snapshot exists in the "completed snapshots folder".
*
* @param snapshot expected snapshot to check
* @return <tt>true</tt> if the snapshot is stored on the {@link FileSystem}, <tt>false</tt> if is
* not stored
* @throws IOException if the filesystem throws an unexpected exception,
* @throws IllegalArgumentException if snapshot name is invalid.
*/
private boolean isSnapshotCompleted(SnapshotDescription snapshot) throws IOException {
try {
final Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshot, rootDir);
FileSystem fs = master.getMasterFileSystem().getFileSystem();
// check to see if the snapshot already exists
return fs.exists(snapshotDir);
} catch (IllegalArgumentException iae) {
throw new UnknownSnapshotException("Unexpected exception thrown", iae);
}
}
/**
* Restore or Clone the specified snapshot
*
* @param reqSnapshot
* @param nonceGroup unique value to prevent duplicated RPC
* @param nonce unique value to prevent duplicated RPC
* @throws IOException
*/
public long restoreOrCloneSnapshot(
SnapshotDescription reqSnapshot, final long nonceGroup, final long nonce) throws IOException {
FileSystem fs = master.getMasterFileSystem().getFileSystem();
Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(reqSnapshot, rootDir);
// check if the snapshot exists
if (!fs.exists(snapshotDir)) {
LOG.error("A Snapshot named '" + reqSnapshot.getName() + "' does not exist.");
throw new SnapshotDoesNotExistException(ProtobufUtil.createSnapshotDesc(reqSnapshot));
}
// Get snapshot info from file system. The reqSnapshot is a "fake" snapshotInfo with
// just the snapshot "name" and table name to restore. It does not contains the "real" snapshot
// information.
SnapshotDescription snapshot = SnapshotDescriptionUtils.readSnapshotInfo(fs, snapshotDir);
SnapshotManifest manifest =
SnapshotManifest.open(master.getConfiguration(), fs, snapshotDir, snapshot);
HTableDescriptor snapshotTableDesc = manifest.getTableDescriptor();
TableName tableName = TableName.valueOf(reqSnapshot.getTable());
// stop tracking "abandoned" handlers
cleanupSentinels();
// Verify snapshot validity
SnapshotReferenceUtil.verifySnapshot(master.getConfiguration(), fs, manifest);
// Execute the restore/clone operation
long procId;
if (MetaTableAccessor.tableExists(master.getConnection(), tableName)) {
procId =
restoreSnapshot(reqSnapshot, tableName, snapshot, snapshotTableDesc, nonceGroup, nonce);
} else {
procId =
cloneSnapshot(reqSnapshot, tableName, snapshot, snapshotTableDesc, nonceGroup, nonce);
}
return procId;
}
/**
* Check to make sure that we are OK to run the passed snapshot. Checks to make sure that we
* aren't already running a snapshot or restore on the requested table.
*
* @param snapshot description of the snapshot we want to start
* @throws HBaseSnapshotException if the filesystem could not be prepared to start the snapshot
*/
private synchronized void prepareToTakeSnapshot(SnapshotDescription snapshot)
throws HBaseSnapshotException {
FileSystem fs = master.getMasterFileSystem().getFileSystem();
Path workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, rootDir);
TableName snapshotTable = TableName.valueOf(snapshot.getTable());
// make sure we aren't already running a snapshot
if (isTakingSnapshot(snapshot)) {
SnapshotSentinel handler = this.snapshotHandlers.get(snapshotTable);
throw new SnapshotCreationException(
"Rejected taking "
+ ClientSnapshotDescriptionUtils.toString(snapshot)
+ " because we are already running another snapshot "
+ (handler != null
? ("on the same table "
+ ClientSnapshotDescriptionUtils.toString(handler.getSnapshot()))
: "with the same name"),
ProtobufUtil.createSnapshotDesc(snapshot));
}
// make sure we aren't running a restore on the same table
if (isRestoringTable(snapshotTable)) {
throw new SnapshotCreationException(
"Rejected taking "
+ ClientSnapshotDescriptionUtils.toString(snapshot)
+ " because we are already have a restore in progress on the same snapshot.");
}
try {
// delete the working directory, since we aren't running the snapshot. Likely leftovers
// from a failed attempt.
fs.delete(workingDir, true);
// recreate the working directory for the snapshot
if (!fs.mkdirs(workingDir)) {
throw new SnapshotCreationException(
"Couldn't create working directory (" + workingDir + ") for snapshot",
ProtobufUtil.createSnapshotDesc(snapshot));
}
} catch (HBaseSnapshotException e) {
throw e;
} catch (IOException e) {
throw new SnapshotCreationException(
"Exception while checking to see if snapshot could be started.",
e,
ProtobufUtil.createSnapshotDesc(snapshot));
}
}
/**
* Gets the list of all completed snapshots.
*
* @return list of SnapshotDescriptions
* @throws IOException File system exception
*/
public List<SnapshotDescription> getCompletedSnapshots() throws IOException {
return getCompletedSnapshots(SnapshotDescriptionUtils.getSnapshotsDir(rootDir));
}
/**
* Called at startup, to verify if snapshot operation is supported, and to avoid starting the
* master if there're snapshots present but the cleaners needed are missing. Otherwise we can end
* up with snapshot data loss.
*
* @param conf The {@link Configuration} object to use
* @param mfs The MasterFileSystem to use
* @throws IOException in case of file-system operation failure
* @throws UnsupportedOperationException in case cleaners are missing and there're snapshot in the
* system
*/
private void checkSnapshotSupport(final Configuration conf, final MasterFileSystem mfs)
throws IOException, UnsupportedOperationException {
// Verify if snapshot is disabled by the user
String enabled = conf.get(HBASE_SNAPSHOT_ENABLED);
boolean snapshotEnabled = conf.getBoolean(HBASE_SNAPSHOT_ENABLED, false);
boolean userDisabled = (enabled != null && enabled.trim().length() > 0 && !snapshotEnabled);
// Extract cleaners from conf
Set<String> hfileCleaners = new HashSet<String>();
String[] cleaners = conf.getStrings(HFileCleaner.MASTER_HFILE_CLEANER_PLUGINS);
if (cleaners != null) Collections.addAll(hfileCleaners, cleaners);
Set<String> logCleaners = new HashSet<String>();
cleaners = conf.getStrings(HConstants.HBASE_MASTER_LOGCLEANER_PLUGINS);
if (cleaners != null) Collections.addAll(logCleaners, cleaners);
// check if an older version of snapshot directory was present
Path oldSnapshotDir = new Path(mfs.getRootDir(), HConstants.OLD_SNAPSHOT_DIR_NAME);
FileSystem fs = mfs.getFileSystem();
List<SnapshotDescription> ss = getCompletedSnapshots(new Path(rootDir, oldSnapshotDir));
if (ss != null && !ss.isEmpty()) {
LOG.error("Snapshots from an earlier release were found under: " + oldSnapshotDir);
LOG.error("Please rename the directory as " + HConstants.SNAPSHOT_DIR_NAME);
}
// If the user has enabled the snapshot, we force the cleaners to be present
// otherwise we still need to check if cleaners are enabled or not and verify
// that there're no snapshot in the .snapshot folder.
if (snapshotEnabled) {
// Inject snapshot cleaners, if snapshot.enable is true
hfileCleaners.add(SnapshotHFileCleaner.class.getName());
hfileCleaners.add(HFileLinkCleaner.class.getName());
// Set cleaners conf
conf.setStrings(
HFileCleaner.MASTER_HFILE_CLEANER_PLUGINS,
hfileCleaners.toArray(new String[hfileCleaners.size()]));
conf.setStrings(
HConstants.HBASE_MASTER_LOGCLEANER_PLUGINS,
logCleaners.toArray(new String[logCleaners.size()]));
} else {
// Verify if cleaners are present
snapshotEnabled =
hfileCleaners.contains(SnapshotHFileCleaner.class.getName())
&& hfileCleaners.contains(HFileLinkCleaner.class.getName());
// Warn if the cleaners are enabled but the snapshot.enabled property is false/not set.
if (snapshotEnabled) {
LOG.warn(
"Snapshot log and hfile cleaners are present in the configuration, "
+ "but the '"
+ HBASE_SNAPSHOT_ENABLED
+ "' property "
+ (userDisabled ? "is set to 'false'." : "is not set."));
}
}
// Mark snapshot feature as enabled if cleaners are present and user has not disabled it.
this.isSnapshotSupported = snapshotEnabled && !userDisabled;
// If cleaners are not enabled, verify that there're no snapshot in the .snapshot folder
// otherwise we end up with snapshot data loss.
if (!snapshotEnabled) {
LOG.info("Snapshot feature is not enabled, missing log and hfile cleaners.");
Path snapshotDir = SnapshotDescriptionUtils.getSnapshotsDir(mfs.getRootDir());
if (fs.exists(snapshotDir)) {
FileStatus[] snapshots =
FSUtils.listStatus(
fs,
snapshotDir,
new SnapshotDescriptionUtils.CompletedSnaphotDirectoriesFilter(fs));
if (snapshots != null) {
LOG.error("Snapshots are present, but cleaners are not enabled.");
checkSnapshotSupport();
}
}
}
}
/**
* Execute the core common portions of taking a snapshot. The {@link #snapshotRegions(List)} call
* should get implemented for each snapshot flavor.
*/
@Override
@edu.umd.cs.findbugs.annotations.SuppressWarnings(
value = "REC_CATCH_EXCEPTION",
justification = "Intentional")
public void process() {
String msg =
"Running "
+ snapshot.getType()
+ " table snapshot "
+ snapshot.getName()
+ " "
+ eventType
+ " on table "
+ snapshotTable;
LOG.info(msg);
status.setStatus(msg);
try {
// If regions move after this meta scan, the region specific snapshot should fail, triggering
// an external exception that gets captured here.
// write down the snapshot info in the working directory
SnapshotDescriptionUtils.writeSnapshotInfo(snapshot, workingDir, fs);
snapshotManifest.addTableDescriptor(this.htd);
monitor.rethrowException();
List<Pair<HRegionInfo, ServerName>> regionsAndLocations;
if (TableName.META_TABLE_NAME.equals(snapshotTable)) {
regionsAndLocations =
new MetaTableLocator().getMetaRegionsAndLocations(server.getZooKeeper());
} else {
regionsAndLocations =
MetaTableAccessor.getTableRegionsAndLocations(
server.getConnection(), snapshotTable, false);
}
// run the snapshot
snapshotRegions(regionsAndLocations);
monitor.rethrowException();
// extract each pair to separate lists
Set<String> serverNames = new HashSet<String>();
for (Pair<HRegionInfo, ServerName> p : regionsAndLocations) {
if (p != null && p.getFirst() != null && p.getSecond() != null) {
HRegionInfo hri = p.getFirst();
if (hri.isOffline() && (hri.isSplit() || hri.isSplitParent())) continue;
serverNames.add(p.getSecond().toString());
}
}
// flush the in-memory state, and write the single manifest
status.setStatus("Consolidate snapshot: " + snapshot.getName());
snapshotManifest.consolidate();
// verify the snapshot is valid
status.setStatus("Verifying snapshot: " + snapshot.getName());
verifier.verifySnapshot(this.workingDir, serverNames);
// complete the snapshot, atomically moving from tmp to .snapshot dir.
completeSnapshot(this.snapshotDir, this.workingDir, this.fs);
msg = "Snapshot " + snapshot.getName() + " of table " + snapshotTable + " completed";
status.markComplete(msg);
LOG.info(msg);
metricsSnapshot.addSnapshot(status.getCompletionTimestamp() - status.getStartTime());
} catch (Exception e) { // FindBugs: REC_CATCH_EXCEPTION
status.abort(
"Failed to complete snapshot "
+ snapshot.getName()
+ " on table "
+ snapshotTable
+ " because "
+ e.getMessage());
String reason =
"Failed taking snapshot "
+ ClientSnapshotDescriptionUtils.toString(snapshot)
+ " due to exception:"
+ e.getMessage();
LOG.error(reason, e);
ForeignException ee = new ForeignException(reason, e);
monitor.receive(ee);
// need to mark this completed to close off and allow cleanup to happen.
cancel(reason);
} finally {
LOG.debug("Launching cleanup of working dir:" + workingDir);
try {
// if the working dir is still present, the snapshot has failed. it is present we delete
// it.
if (fs.exists(workingDir) && !this.fs.delete(workingDir, true)) {
LOG.error("Couldn't delete snapshot working directory:" + workingDir);
}
} catch (IOException e) {
LOG.error("Couldn't delete snapshot working directory:" + workingDir);
}
releaseTableLock();
}
}
