/**
* Fences a ledger. From this point on, clients will be unable to write to this ledger. Only
* recoveryAddEntry will be able to add entries to the ledger. This method is idempotent. Once a
* ledger is fenced, it can never be unfenced. Fencing a fenced ledger has no effect.
*/
public SettableFuture<Boolean> fenceLedger(long ledgerId, byte[] masterKey)
throws IOException, BookieException {
LedgerDescriptor handle = handles.getHandle(ledgerId, masterKey);
boolean success;
synchronized (handle) {
success = handle.setFenced();
}
if (success) {
// fenced first time, we should add the key to journal ensure we can rebuild
ByteBuffer bb = ByteBuffer.allocate(8 + 8);
bb.putLong(ledgerId);
bb.putLong(METAENTRY_ID_FENCE_KEY);
bb.flip();
FutureWriteCallback fwc = new FutureWriteCallback();
LOG.debug("record fenced state for ledger {} in journal.", ledgerId);
journal.logAddEntry(bb, fwc, null);
return fwc.getResult();
} else {
// already fenced
SettableFuture<Boolean> successFuture = SettableFuture.create();
successFuture.set(true);
return successFuture;
}
}
