private void doTransition(
DataNode datanode, StorageDirectory sd, NamespaceInfo nsInfo, StartupOption startOpt)
throws IOException {
if (startOpt == StartupOption.ROLLBACK) {
throw new RuntimeException("未实现");
}
readProperties(sd);
checkVersionUpgradable(this.layoutVersion);
// 版本号为负数，越小越高,文件里面的layoutVersion必须比hadoop版本大或者等于
assert this.layoutVersion >= HdfsConstants.DATANODE_LAYOUT_VERSION : "不允许将来的版本";
boolean federationSupported =
DataNodeLayoutVersion.supports(LayoutVersion.Feature.FEDERATION, layoutVersion);
if (!federationSupported && getNamespaceID() != nsInfo.getNamespaceID()) {
throw new IOException(
"Incompatible namespaceIDs in "
+ sd.getRoot().getCanonicalPath()
+ ": namenode namespaceID = "
+ nsInfo.getNamespaceID()
+ "; datanode namespaceID = "
+ getNamespaceID());
}
if (federationSupported && !getClusterID().equals(nsInfo.getClusterID())) {
throw new IOException(
"Incompatible clusterIDs in "
+ sd.getRoot().getCanonicalPath()
+ ": namenode clusterID = "
+ nsInfo.getClusterID()
+ "; datanode clusterID = "
+ getClusterID());
}
boolean haveValidStorageId =
DataNodeLayoutVersion.supports(
LayoutVersion.Feature.ADD_DATANODE_AND_STORAGE_UUIDS, layoutVersion)
&& DatanodeStorage.isValidStorageId(sd.getStorageUuid());
if (this.layoutVersion == HdfsConstants.DATANODE_LAYOUT_VERSION) {
createStorageID(sd, !haveValidStorageId);
return;
}
throw new IOException(
"BUG: The stored LV = "
+ this.getLayoutVersion()
+ " is newer than the supported LV = "
+ HdfsConstants.DATANODE_LAYOUT_VERSION);
}
void format(StorageDirectory sd, NamespaceInfo nsInfo, String datanodeUuid) throws IOException {
sd.clearDirectory();
this.layoutVersion = HdfsConstants.DATANODE_LAYOUT_VERSION;
this.clusterID = nsInfo.getClusterID();
this.namespaceID = nsInfo.getNamespaceID();
this.cTime = 0;
setDatanodeUuid(datanodeUuid);
if (sd.getStorageUuid() == null) {
// 分配新的 Storage UUID.
sd.setStorageUuid(DatanodeStorage.generateUuid());
}
writeProperties(sd);
}
synchronized List<StorageLocation> addStorageLocations(
DataNode datanode,
NamespaceInfo nsInfo,
Collection<StorageLocation> dataDirs,
StartupOption startOpt)
throws IOException {
final String bpid = nsInfo.getBlockPoolID();
List<StorageLocation> successVolumes = Lists.newArrayList();
for (StorageLocation dataDir : dataDirs) {
File root = dataDir.getFile();
if (!containsStorageDir(root)) {
try {
StorageDirectory sd = loadStorageDirectory(datanode, nsInfo, root, startOpt);
addStorageDir(sd);
} catch (IOException e) {
LOG.warn(e);
continue;
}
} else {
LOG.info("Storage directory " + dataDir + " has already been used.");
}
List<File> bpDataDirs = new ArrayList<File>();
bpDataDirs.add(BlockPoolSliceStorage.getBpRoot(bpid, new File(root, STORAGE_DIR_CURRENT)));
try {
makeBlockPoolDataDir(bpDataDirs, null);
BlockPoolSliceStorage bpStorage = this.bpStorageMap.get(bpid);
if (bpStorage == null) {
bpStorage =
new BlockPoolSliceStorage(
nsInfo.getNamespaceID(), bpid, nsInfo.getCTime(), nsInfo.getClusterID());
}
bpStorage.recoverTransitionRead(datanode, nsInfo, bpDataDirs, startOpt);
addBlockPoolStorage(bpid, bpStorage);
} catch (IOException e) {
LOG.warn("Failed to add storage for block pool: " + bpid + " : " + e.getMessage());
continue;
}
successVolumes.add(dataDir);
}
return successVolumes;
}