long startTime = now();
bnImage.freezeNamespaceAtNextRoll();
NamenodeCommand cmd =
getRemoteNamenodeProxy().startCheckpoint(backupNode.getRegistration());
CheckpointCommand cpCmd = null;
switch(cmd.getAction()) {
case NamenodeProtocol.ACT_SHUTDOWN:
shutdown();
throw new IOException("Name-node " + backupNode.nnRpcAddress
+ " requested shutdown.");
case NamenodeProtocol.ACT_CHECKPOINT:
cpCmd = (CheckpointCommand)cmd;
break;
default:
throw new IOException("Unsupported NamenodeCommand: "+cmd.getAction());
}
bnImage.waitUntilNamespaceFrozen();
CheckpointSignature sig = cpCmd.getSignature();
// Make sure we're talking to the same NN!
sig.validateStorageInfo(bnImage);
long lastApplied = bnImage.getLastAppliedTxId();
LOG.debug("Doing checkpoint. Last applied: " + lastApplied);
RemoteEditLogManifest manifest =
getRemoteNamenodeProxy().getEditLogManifest(bnImage.getLastAppliedTxId() + 1);
boolean needReloadImage = false;
if (!manifest.getLogs().isEmpty()) {
RemoteEditLog firstRemoteLog = manifest.getLogs().get(0);
// we don't have enough logs to roll forward using only logs. Need
// to download and load the image.
if (firstRemoteLog.getStartTxId() > lastApplied + 1) {
LOG.info("Unable to roll forward using only logs. Downloading " +
"image with txid " + sig.mostRecentCheckpointTxId);
MD5Hash downloadedHash = TransferFsImage.downloadImageToStorage(
backupNode.nnHttpAddress, sig.mostRecentCheckpointTxId, bnStorage,
true);
bnImage.saveDigestAndRenameCheckpointImage(NameNodeFile.IMAGE,
sig.mostRecentCheckpointTxId, downloadedHash);
lastApplied = sig.mostRecentCheckpointTxId;
needReloadImage = true;
}
if (firstRemoteLog.getStartTxId() > lastApplied + 1) {
throw new IOException("No logs to roll forward from " + lastApplied);
}
// get edits files
for (RemoteEditLog log : manifest.getLogs()) {
TransferFsImage.downloadEditsToStorage(
backupNode.nnHttpAddress, log, bnStorage);
}
if(needReloadImage) {
LOG.info("Loading image with txid " + sig.mostRecentCheckpointTxId);
File file = bnStorage.findImageFile(NameNodeFile.IMAGE,
sig.mostRecentCheckpointTxId);
bnImage.reloadFromImageFile(file, backupNode.getNamesystem());
}
rollForwardByApplyingLogs(manifest, bnImage, backupNode.getNamesystem());
}
long txid = bnImage.getLastAppliedTxId();
backupNode.namesystem.writeLock();
try {
backupNode.namesystem.setImageLoaded();
if(backupNode.namesystem.getBlocksTotal() > 0) {
backupNode.namesystem.setBlockTotal();
}
bnImage.saveFSImageInAllDirs(backupNode.getNamesystem(), txid);
bnStorage.writeAll();
} finally {
backupNode.namesystem.writeUnlock();
}
if(cpCmd.needToReturnImage()) {
TransferFsImage.uploadImageFromStorage(backupNode.nnHttpAddress, conf,
bnStorage, NameNodeFile.IMAGE, txid);
}
getRemoteNamenodeProxy().endCheckpoint(backupNode.getRegistration(), sig);