org.apache.bookkeeper.client
Class BookKeeper

java.lang.Object
  org.apache.bookkeeper.client.BookKeeper

All Implemented Interfaces:

Watcher

public class BookKeeper
extends Object
implements Watcher

BookKeeper client. We assume there is one single writer to a ledger at any time. There are three possible operations: start a new ledger, write to a ledger, and read from a ledger. For the ZooKeeper layout, please refer to BKDefs.java.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.zookeeper.Watcher

Watcher.Event

Constructor Summary

BookKeeper(String servers)

Method Summary

void	asyncCreateLedger(int ensSize, int qSize, LedgerHandle.QMode mode, byte[] passwd, AsyncCallback.CreateCallback cb, Object ctx) Asychronous call to create ledger
void	asyncOpenLedger(long lId, byte[] passwd, AsyncCallback.OpenCallback cb, Object ctx)
LedgerHandle	createLedger(byte[] passwd) Creates a new ledger.
LedgerHandle	createLedger(int ensSize, int qSize, LedgerHandle.QMode mode, byte[] passwd) Creates a new ledger.
void	halt() Halts all bookie handles
boolean	hasClosed(long ledgerId) Check if close node exists.
LedgerHandle	openLedger(long lId, byte[] passwd) Open existing ledger for reading.
void	process(WatchedEvent event) Watcher method.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BookKeeper

public BookKeeper(String servers)
           throws KeeperException,
                  IOException

Throws:

KeeperException

IOException

Method Detail

process

public void process(WatchedEvent event)

Watcher method.

Specified by:

process in interface Watcher

createLedger

public LedgerHandle createLedger(int ensSize,
                                 int qSize,
                                 LedgerHandle.QMode mode,
                                 byte[] passwd)
                          throws KeeperException,
                                 InterruptedException,
                                 IOException,
                                 BKException

Creates a new ledger. To create a ledger, we need to specify the ensemble size, the quorum size, the operation mode, and a password. The ensemble size and the quorum size depend upon the operation mode. The operation mode can be GENERIC, VERIFIABLE, or FREEFORM (debugging). The password is used not only to authenticate access to a ledger, but also to verify entries in verifiable ledgers.

Parameters:

ensSize - ensemble size

qSize - quorum size

mode - quorum mode: VERIFIABLE (default), GENERIC, or FREEFORM

passwd - password

Throws:

KeeperException

InterruptedException

IOException

BKException

createLedger

public LedgerHandle createLedger(byte[] passwd)
                          throws KeeperException,
                                 BKException,
                                 InterruptedException,
                                 IOException

Creates a new ledger. Default of 3 servers, and quorum of 2 servers, verifiable ledger.

Parameters:

passwd - password

Throws:

KeeperException

BKException

InterruptedException

IOException

asyncCreateLedger

public void asyncCreateLedger(int ensSize,
                              int qSize,
                              LedgerHandle.QMode mode,
                              byte[] passwd,
                              AsyncCallback.CreateCallback cb,
                              Object ctx)
                       throws KeeperException,
                              InterruptedException,
                              IOException,
                              BKException

Asychronous call to create ledger

Parameters:

ensSize -

qSize -

mode -

passwd -

cb -

ctx -

Throws:

KeeperException

InterruptedException

IOException

BKException

openLedger

public LedgerHandle openLedger(long lId,
                               byte[] passwd)
                        throws KeeperException,
                               InterruptedException,
                               IOException,
                               BKException

Open existing ledger for reading. Default for quorum size is 2.

Parameters:

long - the long corresponding to the ledger id

byte[] - byte array corresponding to the password to access a ledger

int - the quorum size, it has to be at least ceil(n+1/2)

Throws:

KeeperException

InterruptedException

IOException

BKException

asyncOpenLedger

public void asyncOpenLedger(long lId,
                            byte[] passwd,
                            AsyncCallback.OpenCallback cb,
                            Object ctx)
                     throws InterruptedException

Throws:

InterruptedException

hasClosed

public boolean hasClosed(long ledgerId)
                  throws KeeperException,
                         InterruptedException

Check if close node exists.

Parameters:

ledgerId - id of the ledger to check

Throws:

KeeperException

InterruptedException

halt

public void halt()
          throws InterruptedException

Halts all bookie handles

Throws:

InterruptedException