private void doSnapshot(final Snapshot snapshot) throws IndexShardGatewaySnapshotFailedException {
ImmutableMap<String, BlobMetaData> blobs;
try {
blobs = blobContainer.listBlobs();
} catch (IOException e) {
throw new IndexShardGatewaySnapshotFailedException(shardId, "failed to list blobs", e);
}
long generation = findLatestFileNameGeneration(blobs);
CommitPoints commitPoints = buildCommitPoints(blobs);
currentSnapshotStatus.index().startTime(System.currentTimeMillis());
currentSnapshotStatus.updateStage(SnapshotStatus.Stage.INDEX);
final SnapshotIndexCommit snapshotIndexCommit = snapshot.indexCommit();
final Translog.Snapshot translogSnapshot = snapshot.translogSnapshot();
final CountDownLatch indexLatch = new CountDownLatch(snapshotIndexCommit.getFiles().length);
final CopyOnWriteArrayList<Throwable> failures = new CopyOnWriteArrayList<Throwable>();
final List<CommitPoint.FileInfo> indexCommitPointFiles = Lists.newArrayList();
int indexNumberOfFiles = 0;
long indexTotalFilesSize = 0;
for (final String fileName : snapshotIndexCommit.getFiles()) {
StoreFileMetaData md;
try {
md = store.metaData(fileName);
} catch (IOException e) {
throw new IndexShardGatewaySnapshotFailedException(shardId, "Failed to get store file metadata", e);
}
boolean snapshotRequired = false;
if (snapshot.indexChanged() && fileName.equals(snapshotIndexCommit.getSegmentsFileName())) {
snapshotRequired = true; // we want to always snapshot the segment file if the index changed
}
CommitPoint.FileInfo fileInfo = commitPoints.findPhysicalIndexFile(fileName);
if (fileInfo == null || !fileInfo.isSame(md) || !commitPointFileExistsInBlobs(fileInfo, blobs)) {
// commit point file does not exists in any commit point, or has different length, or does not fully exists in the listed blobs
snapshotRequired = true;
}
if (snapshotRequired) {
indexNumberOfFiles++;
indexTotalFilesSize += md.length();
// create a new FileInfo
try {
CommitPoint.FileInfo snapshotFileInfo = new CommitPoint.FileInfo(fileNameFromGeneration(++generation), fileName, md.length(), md.checksum());
indexCommitPointFiles.add(snapshotFileInfo);
snapshotFile(snapshotIndexCommit.getDirectory(), snapshotFileInfo, indexLatch, failures);
} catch (IOException e) {
failures.add(e);
indexLatch.countDown();
}
} else {
indexCommitPointFiles.add(fileInfo);
indexLatch.countDown();
}
}
currentSnapshotStatus.index().files(indexNumberOfFiles, indexTotalFilesSize);
try {
indexLatch.await();
} catch (InterruptedException e) {
failures.add(e);
}
if (!failures.isEmpty()) {
throw new IndexShardGatewaySnapshotFailedException(shardId(), "Failed to perform snapshot (index files)", failures.get(failures.size() - 1));
}
currentSnapshotStatus.index().time(System.currentTimeMillis() - currentSnapshotStatus.index().startTime());
currentSnapshotStatus.updateStage(SnapshotStatus.Stage.TRANSLOG);
currentSnapshotStatus.translog().startTime(System.currentTimeMillis());
// Note, we assume the snapshot is always started from "base 0". We need to seek forward if we want to lastTranslogPosition if we want the delta
List<CommitPoint.FileInfo> translogCommitPointFiles = Lists.newArrayList();
int expectedNumberOfOperations = 0;
boolean snapshotRequired = false;
if (snapshot.newTranslogCreated()) {
if (translogSnapshot.lengthInBytes() > 0) {
snapshotRequired = true;
expectedNumberOfOperations = translogSnapshot.estimatedTotalOperations();
}
} else {
// if we have a commit point, check that we have all the files listed in it in the blob store
if (!commitPoints.commits().isEmpty()) {
CommitPoint commitPoint = commitPoints.commits().get(0);
boolean allTranslogFilesExists = true;
for (CommitPoint.FileInfo fileInfo : commitPoint.translogFiles()) {
if (!commitPointFileExistsInBlobs(fileInfo, blobs)) {
allTranslogFilesExists = false;
break;
}
}
// if everything exists, we can seek forward in case there are new operations, otherwise, we copy over all again...
if (allTranslogFilesExists) {
translogCommitPointFiles.addAll(commitPoint.translogFiles());
if (snapshot.sameTranslogNewOperations()) {
translogSnapshot.seekForward(snapshot.lastTranslogLength());
if (translogSnapshot.lengthInBytes() > 0) {
snapshotRequired = true;
expectedNumberOfOperations = translogSnapshot.estimatedTotalOperations() - snapshot.lastTotalTranslogOperations();
}
} // else (no operations, nothing to snapshot)
} else {
// a full translog snapshot is required
if (translogSnapshot.lengthInBytes() > 0) {
expectedNumberOfOperations = translogSnapshot.estimatedTotalOperations();
snapshotRequired = true;
}
}
} else {
// no commit point, snapshot all the translog
if (translogSnapshot.lengthInBytes() > 0) {
expectedNumberOfOperations = translogSnapshot.estimatedTotalOperations();
snapshotRequired = true;
}
}
}
currentSnapshotStatus.translog().expectedNumberOfOperations(expectedNumberOfOperations);
if (snapshotRequired) {
CommitPoint.FileInfo addedTranslogFileInfo = new CommitPoint.FileInfo(fileNameFromGeneration(++generation), "translog-" + translogSnapshot.translogId(), translogSnapshot.lengthInBytes(), null /* no need for checksum in translog */);
translogCommitPointFiles.add(addedTranslogFileInfo);
try {
snapshotTranslog(translogSnapshot, addedTranslogFileInfo);
} catch (Exception e) {
throw new IndexShardGatewaySnapshotFailedException(shardId, "Failed to snapshot translog", e);
}
}
currentSnapshotStatus.translog().time(System.currentTimeMillis() - currentSnapshotStatus.translog().startTime());
// now create and write the commit point
currentSnapshotStatus.updateStage(SnapshotStatus.Stage.FINALIZE);
long version = 0;
if (!commitPoints.commits().isEmpty()) {
version = commitPoints.commits().iterator().next().version() + 1;
}
String commitPointName = "commit-" + Long.toString(version, Character.MAX_RADIX);
CommitPoint commitPoint = new CommitPoint(version, commitPointName, CommitPoint.Type.GENERATED, indexCommitPointFiles, translogCommitPointFiles);
try {
byte[] commitPointData = CommitPoints.toXContent(commitPoint);
blobContainer.writeBlob(commitPointName, new FastByteArrayInputStream(commitPointData), commitPointData.length);
} catch (Exception e) {
throw new IndexShardGatewaySnapshotFailedException(shardId, "Failed to write commit point", e);
}
// delete all files that are not referenced by any commit point
// build a new CommitPoint, that includes this one and all the saved ones
List<CommitPoint> newCommitPointsList = Lists.newArrayList();