/**
* 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;
}
/**
* 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();
}
}
}
}