/**
* 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));
}
}
/**
* 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));
}
}
/**
* Check if the specified snapshot is done
*
* @param expected
* @return true if snapshot is ready to be restored, false if it is still being taken.
* @throws IOException IOException if error from HDFS or RPC
* @throws UnknownSnapshotException if snapshot is invalid or does not exist.
*/
public boolean isSnapshotDone(SnapshotDescription expected) throws IOException {
// check the request to make sure it has a snapshot
if (expected == null) {
throw new UnknownSnapshotException(
"No snapshot name passed in request, can't figure out which snapshot you want to check.");
}
String ssString = ClientSnapshotDescriptionUtils.toString(expected);
// check to see if the sentinel exists,
// and if the task is complete removes it from the in-progress snapshots map.
SnapshotSentinel handler = removeSentinelIfFinished(this.snapshotHandlers, expected);
// stop tracking "abandoned" handlers
cleanupSentinels();
if (handler == null) {
// If there's no handler in the in-progress map, it means one of the following:
// - someone has already requested the snapshot state
// - the requested snapshot was completed long time ago (cleanupSentinels() timeout)
// - the snapshot was never requested
// In those cases returns to the user the "done state" if the snapshots exists on disk,
// otherwise raise an exception saying that the snapshot is not running and doesn't exist.
if (!isSnapshotCompleted(expected)) {
throw new UnknownSnapshotException(
"Snapshot "
+ ssString
+ " is not currently running or one of the known completed snapshots.");
}
// was done, return true;
return true;
}
// pass on any failure we find in the sentinel
try {
handler.rethrowExceptionIfFailed();
} catch (ForeignException e) {
// Give some procedure info on an exception.
String status;
Procedure p = coordinator.getProcedure(expected.getName());
if (p != null) {
status = p.getStatus();
} else {
status = expected.getName() + " not found in proclist " + coordinator.getProcedureNames();
}
throw new HBaseSnapshotException(
"Snapshot " + ssString + " had an error. " + status,
e,
ProtobufUtil.createSnapshotDesc(expected));
}
// check to see if we are done
if (handler.isFinished()) {
LOG.debug("Snapshot '" + ssString + "' has completed, notifying client.");
return true;
} else if (LOG.isDebugEnabled()) {
LOG.debug("Snapshoting '" + ssString + "' is still in progress!");
}
return false;
}
/**
* 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);
}
}
/**
* Load the information in the SnapshotManifest. Called by SnapshotManifest.open()
*
* <p>If the format is v2 and there is no data-manifest, means that we are loading an in-progress
* snapshot. Since we support rolling-upgrades, we loook for v1 and v2 regions format.
*/
private void load() throws IOException {
switch (getSnapshotFormat(desc)) {
case SnapshotManifestV1.DESCRIPTOR_VERSION:
{
this.htd =
FSTableDescriptors.getTableDescriptorFromFs(fs, workingDir).getHTableDescriptor();
ThreadPoolExecutor tpool = createExecutor("SnapshotManifestLoader");
try {
this.regionManifests =
SnapshotManifestV1.loadRegionManifests(conf, tpool, fs, workingDir, desc);
} finally {
tpool.shutdown();
}
break;
}
case SnapshotManifestV2.DESCRIPTOR_VERSION:
{
SnapshotDataManifest dataManifest = readDataManifest();
if (dataManifest != null) {
htd = ProtobufUtil.convertToHTableDesc(dataManifest.getTableSchema());
regionManifests = dataManifest.getRegionManifestsList();
} else {
// Compatibility, load the v1 regions
// This happens only when the snapshot is in-progress and the cache wants to refresh.
List<SnapshotRegionManifest> v1Regions, v2Regions;
ThreadPoolExecutor tpool = createExecutor("SnapshotManifestLoader");
try {
v1Regions = SnapshotManifestV1.loadRegionManifests(conf, tpool, fs, workingDir, desc);
v2Regions = SnapshotManifestV2.loadRegionManifests(conf, tpool, fs, workingDir, desc);
} catch (InvalidProtocolBufferException e) {
throw new CorruptedSnapshotException(
"unable to parse region manifest " + e.getMessage(), e);
} finally {
tpool.shutdown();
}
if (v1Regions != null && v2Regions != null) {
regionManifests =
new ArrayList<SnapshotRegionManifest>(v1Regions.size() + v2Regions.size());
regionManifests.addAll(v1Regions);
regionManifests.addAll(v2Regions);
} else if (v1Regions != null) {
regionManifests = v1Regions;
} else /* if (v2Regions != null) */ {
regionManifests = v2Regions;
}
}
break;
}
default:
throw new CorruptedSnapshotException(
"Invalid Snapshot version: " + desc.getVersion(),
ProtobufUtil.createSnapshotDesc(desc));
}
}
private RegionVisitor createRegionVisitor(final SnapshotDescription desc) throws IOException {
switch (getSnapshotFormat(desc)) {
case SnapshotManifestV1.DESCRIPTOR_VERSION:
return new SnapshotManifestV1.ManifestBuilder(conf, fs, workingDir);
case SnapshotManifestV2.DESCRIPTOR_VERSION:
return new SnapshotManifestV2.ManifestBuilder(conf, fs, workingDir);
default:
throw new CorruptedSnapshotException(
"Invalid Snapshot version: " + desc.getVersion(),
ProtobufUtil.createSnapshotDesc(desc));
}
}
/**
* 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;
}
/**
* Take a snapshot based on the enabled/disabled state of the table.
*
* @param snapshot
* @throws HBaseSnapshotException when a snapshot specific exception occurs.
* @throws IOException when some sort of generic IO exception occurs.
*/
public void takeSnapshot(SnapshotDescription snapshot) throws IOException {
// check to see if we already completed the snapshot
if (isSnapshotCompleted(snapshot)) {
throw new SnapshotExistsException(
"Snapshot '" + snapshot.getName() + "' already stored on the filesystem.",
ProtobufUtil.createSnapshotDesc(snapshot));
}
LOG.debug("No existing snapshot, attempting snapshot...");
// stop tracking "abandoned" handlers
cleanupSentinels();
// check to see if the table exists
HTableDescriptor desc = null;
try {
desc = master.getTableDescriptors().get(TableName.valueOf(snapshot.getTable()));
} catch (FileNotFoundException e) {
String msg = "Table:" + snapshot.getTable() + " info doesn't exist!";
LOG.error(msg);
throw new SnapshotCreationException(msg, e, ProtobufUtil.createSnapshotDesc(snapshot));
} catch (IOException e) {
throw new SnapshotCreationException(
"Error while geting table description for table " + snapshot.getTable(),
e,
ProtobufUtil.createSnapshotDesc(snapshot));
}
if (desc == null) {
throw new SnapshotCreationException(
"Table '" + snapshot.getTable() + "' doesn't exist, can't take snapshot.",
ProtobufUtil.createSnapshotDesc(snapshot));
}
SnapshotDescription.Builder builder = snapshot.toBuilder();
// if not specified, set the snapshot format
if (!snapshot.hasVersion()) {
builder.setVersion(SnapshotDescriptionUtils.SNAPSHOT_LAYOUT_VERSION);
}
User user = RpcServer.getRequestUser();
if (User.isHBaseSecurityEnabled(master.getConfiguration()) && user != null) {
builder.setOwner(user.getShortName());
}
snapshot = builder.build();
// call pre coproc hook
MasterCoprocessorHost cpHost = master.getMasterCoprocessorHost();
if (cpHost != null) {
cpHost.preSnapshot(snapshot, desc);
}
// if the table is enabled, then have the RS run actually the snapshot work
TableName snapshotTable = TableName.valueOf(snapshot.getTable());
if (master.getTableStateManager().isTableState(snapshotTable, TableState.State.ENABLED)) {
LOG.debug("Table enabled, starting distributed snapshot.");
snapshotEnabledTable(snapshot);
LOG.debug("Started snapshot: " + ClientSnapshotDescriptionUtils.toString(snapshot));
}
// For disabled table, snapshot is created by the master
else if (master.getTableStateManager().isTableState(snapshotTable, TableState.State.DISABLED)) {
LOG.debug("Table is disabled, running snapshot entirely on master.");
snapshotDisabledTable(snapshot);
LOG.debug("Started snapshot: " + ClientSnapshotDescriptionUtils.toString(snapshot));
} else {
LOG.error(
"Can't snapshot table '"
+ snapshot.getTable()
+ "', isn't open or closed, we don't know what to do!");
TablePartiallyOpenException tpoe =
new TablePartiallyOpenException(snapshot.getTable() + " isn't fully open.");
throw new SnapshotCreationException(
"Table is not entirely open or closed", tpoe, ProtobufUtil.createSnapshotDesc(snapshot));
}
// call post coproc hook
if (cpHost != null) {
cpHost.postSnapshot(snapshot, desc);
}
}