ZooKeeperServer (Apache ZooKeeper

java.lang.Object
- org.apache.zookeeper.server.ZooKeeperServer

All Implemented Interfaces:

ServerStats.Provider, SessionTracker.SessionExpirer

Direct Known Subclasses:

QuorumZooKeeperServer, ReadOnlyZooKeeperServer
```
public class ZooKeeperServer
extends Object
implements SessionTracker.SessionExpirer, ServerStats.Provider
```
This class implements a simple standalone ZooKeeperServer. It sets up the following chain of RequestProcessors to process requests: PrepRequestProcessor -> SyncRequestProcessor -> FinalRequestProcessor

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class ZooKeeperServer.MissingSessionException

protected static class ZooKeeperServer.State

Nested Classes
Modifier and Type	Class and Description
`static class`	`ZooKeeperServer.MissingSessionException`
`protected static class`	`ZooKeeperServer.State`

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`DEFAULT_TICK_TIME`
`protected RequestProcessor`	`firstProcessor`
`protected DataTreeBean`	`jmxDataTreeBean`
`protected ZooKeeperServerBean`	`jmxServerBean`
`protected static org.slf4j.Logger`	`LOG`
`protected int`	`maxSessionTimeout` value of -1 indicates unset, use default
`protected int`	`minSessionTimeout` value of -1 indicates unset, use default
`static Exception`	`ok`
`protected ServerCnxnFactory`	`secureServerCnxnFactory`
`protected ServerCnxnFactory`	`serverCnxnFactory`
`protected SessionTracker`	`sessionTracker`
`protected ZooKeeperServer.State`	`state`
`protected int`	`tickTime`

Constructor Summary

Constructors
Constructor and Description
`ZooKeeperServer()` Creates a ZooKeeperServer instance.
`ZooKeeperServer(File snapDir, File logDir, int tickTime)` This constructor is for backward compatibility with the existing unit test code.
`ZooKeeperServer(FileTxnSnapLog txnLogFactory)` Default constructor, relies on the config for its argument values
`ZooKeeperServer(FileTxnSnapLog txnLogFactory, int tickTime)` creates a zookeeperserver instance.
`ZooKeeperServer(FileTxnSnapLog txnLogFactory, int tickTime, int minSessionTimeout, int maxSessionTimeout, ZKDatabase zkDb)` Creates a ZooKeeperServer instance.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected boolean`	`canShutdown()` This can be used while shutting down the server to see whether the server is already shutdown or not.
`protected boolean`	`checkPasswd(long sessionId, byte[] passwd)`
`void`	`closeSession(long sessionId)`
`void`	`closeSession(ServerCnxn cnxn, RequestHeader requestHeader)`
`protected void`	`createSessionTracker()`
`void`	`decInProcess()`
`void`	`dumpConf(PrintWriter pwriter)`
`void`	`dumpEphemerals(PrintWriter pwriter)`
`void`	`expire(SessionTracker.Session session)`
`void`	`finishSessionInit(ServerCnxn cnxn, boolean valid)`
`int`	`getClientPort()`
`ZooKeeperServerConf`	`getConf()`
`long`	`getDataDirSize()`
`Map<Long,Set<String>>`	`getEphemerals()`
`int`	`getGlobalOutstandingLimit()`
`int`	`getInProcess()`
`long`	`getLastProcessedZxid()` return the last proceesed id from the datatree
`long`	`getLogDirSize()`
`int`	`getMaxClientCnxnsPerHost()` Maximum number of connections allowed from particular host (ip)
`int`	`getMaxSessionTimeout()`
`int`	`getMinSessionTimeout()`
`int`	`getNumAliveConnections()` return the total number of client connections that are alive to this server
`long`	`getOutstandingRequests()` return the outstanding requests in the queue, which havent been processed yet
`int`	`getSecureClientPort()`
`ServerCnxnFactory`	`getSecureServerCnxnFactory()`
`ServerCnxnFactory`	`getServerCnxnFactory()`
`long`	`getServerId()`
`Map<Long,Set<Long>>`	`getSessionExpiryMap()`
`SessionTracker`	`getSessionTracker()`
`static int`	`getSnapCount()`
`String`	`getState()`
`int`	`getTickTime()`
`long`	`getTxnLogElapsedSyncTime()` Returns the elapsed sync of time of transaction log in milliseconds.
`FileTxnSnapLog`	`getTxnLogFactory()`
`ZKDatabase`	`getZKDatabase()` get the zookeeper database for this server
`ZooKeeperServerListener`	`getZooKeeperServerListener()`
`long`	`getZxid()`
`void`	`incInProcess()`
`boolean`	`isRunning()`
`protected void`	`killSession(long sessionId, long zxid)`
`void`	`loadData()` Restore sessions and data
`void`	`processConnectRequest(ServerCnxn cnxn, ByteBuffer incomingBuffer)`
`void`	`processPacket(ServerCnxn cnxn, ByteBuffer incomingBuffer)`
`DataTree.ProcessTxnResult`	`processTxn(Request request)`
`DataTree.ProcessTxnResult`	`processTxn(TxnHeader hdr, Record txn)`
`protected void`	`registerJMX()`
`void`	`reopenSession(ServerCnxn cnxn, long sessionId, byte[] passwd, int sessionTimeout)`
`protected void`	`revalidateSession(ServerCnxn cnxn, long sessionId, int sessionTimeout)`
`ServerStats`	`serverStats()`
`void`	`setCreateSessionTrackerServerId(int newId)` Change the server ID used by `createSessionTracker()`.
`protected void`	`setLocalSessionFlag(Request si)` If the underlying Zookeeper server support local session, this method will set a isLocalSession to true if a request is associated with a local session.
`void`	`setMaxSessionTimeout(int max)`
`void`	`setMinSessionTimeout(int min)`
`void`	`setOwner(long id, Object owner)` set the owner of this session as owner
`void`	`setSecureServerCnxnFactory(ServerCnxnFactory factory)`
`void`	`setServerCnxnFactory(ServerCnxnFactory factory)`
`protected void`	`setState(ZooKeeperServer.State state)` Sets the state of ZooKeeper server.
`void`	`setTickTime(int tickTime)`
`void`	`setTxnLogFactory(FileTxnSnapLog txnLog)`
`protected void`	`setupRequestProcessors()`
`void`	`setZKDatabase(ZKDatabase zkDb)` set the zkdatabase for this zookeeper server
`void`	`setZxid(long zxid)`
`boolean`	`shouldThrottle(long outStandingCount)`
`void`	`shutdown()`
`void`	`shutdown(boolean fullyShutDown)` Shut down the server instance
`void`	`startdata()`
`protected void`	`startSessionTracker()`
`void`	`startup()`
`void`	`submitRequest(Request si)`
`void`	`takeSnapshot()`
`void`	`truncateLog(long zxid)` trunccate the log to get in sync with others if in a quorum
`protected void`	`unregisterJMX()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - LOG
```
protected static final org.slf4j.Logger LOG
```
  - jmxServerBean
```
protected ZooKeeperServerBean jmxServerBean
```
  - jmxDataTreeBean
```
protected DataTreeBean jmxDataTreeBean
```
  - DEFAULT_TICK_TIME
```
public static final int DEFAULT_TICK_TIME
```
    See Also:
    
    Constant Field Values
  - tickTime
```
protected int tickTime
```
  - minSessionTimeout
```
protected int minSessionTimeout
```
    value of -1 indicates unset, use default
  - maxSessionTimeout
```
protected int maxSessionTimeout
```
    value of -1 indicates unset, use default
  - sessionTracker
```
protected SessionTracker sessionTracker
```
  - ok
```
public static final Exception ok
```
  - firstProcessor
```
protected RequestProcessor firstProcessor
```
  - state
```
protected volatile ZooKeeperServer.State state
```
  - serverCnxnFactory
```
protected ServerCnxnFactory serverCnxnFactory
```
  - secureServerCnxnFactory
```
protected ServerCnxnFactory secureServerCnxnFactory
```
- Constructor Detail
  - ZooKeeperServer
```
public ZooKeeperServer()
```
    Creates a ZooKeeperServer instance. Nothing is setup, use the setX methods to prepare the instance (eg datadir, datalogdir, ticktime, builder, etc...)
    
    Throws:
    
    IOException
  - ZooKeeperServer
```
public ZooKeeperServer(FileTxnSnapLog txnLogFactory,
                       int tickTime,
                       int minSessionTimeout,
                       int maxSessionTimeout,
                       ZKDatabase zkDb)
```
    Creates a ZooKeeperServer instance. It sets everything up, but doesn't actually start listening for clients until run() is invoked.
    
    Parameters:
    
    dataDir - the directory to put the data
  - ZooKeeperServer
```
public ZooKeeperServer(FileTxnSnapLog txnLogFactory,
                       int tickTime)
                throws IOException
```
    creates a zookeeperserver instance.
    
    Parameters:
    
    txnLogFactory - the file transaction snapshot logging class
    
    tickTime - the ticktime for the server
    
    Throws:
    
    IOException
  - ZooKeeperServer
```
public ZooKeeperServer(File snapDir,
                       File logDir,
                       int tickTime)
                throws IOException
```
    This constructor is for backward compatibility with the existing unit test code. It defaults to FileLogProvider persistence provider.
    
    Throws:
    
    IOException
  - ZooKeeperServer
```
public ZooKeeperServer(FileTxnSnapLog txnLogFactory)
                throws IOException
```
    Default constructor, relies on the config for its argument values
    
    Throws:
    
    IOException
- Method Detail
  - serverStats
```
public ServerStats serverStats()
```
  - dumpConf
```
public void dumpConf(PrintWriter pwriter)
```
  - getConf
```
public ZooKeeperServerConf getConf()
```
  - getZKDatabase
```
public ZKDatabase getZKDatabase()
```
    get the zookeeper database for this server
    
    Returns:
    
    the zookeeper database for this server
  - setZKDatabase
```
public void setZKDatabase(ZKDatabase zkDb)
```
    set the zkdatabase for this zookeeper server
    
    Parameters:
    
    zkDb -
  - loadData
```
public void loadData()
              throws IOException,
                     InterruptedException
```
    Restore sessions and data
    
    Throws:
    
    IOException
    
    InterruptedException
  - takeSnapshot
```
public void takeSnapshot()
```
  - getDataDirSize
```
public long getDataDirSize()
```
    Specified by:
    
    getDataDirSize in interface ServerStats.Provider
  - getLogDirSize
```
public long getLogDirSize()
```
    Specified by:
    
    getLogDirSize in interface ServerStats.Provider
  - getZxid
```
public long getZxid()
```
  - getSessionTracker
```
public SessionTracker getSessionTracker()
```
  - setZxid
```
public void setZxid(long zxid)
```
  - closeSession
```
public void closeSession(long sessionId)
```
  - killSession
```
protected void killSession(long sessionId,
                           long zxid)
```
  - expire
```
public void expire(SessionTracker.Session session)
```
    Specified by:
    
    expire in interface SessionTracker.SessionExpirer
  - registerJMX
```
protected void registerJMX()
```
  - startdata
```
public void startdata()
               throws IOException,
                      InterruptedException
```
    Throws:
    
    IOException
    
    InterruptedException
  - startup
```
public void startup()
```
  - setupRequestProcessors
```
protected void setupRequestProcessors()
```
  - getZooKeeperServerListener
```
public ZooKeeperServerListener getZooKeeperServerListener()
```
  - setCreateSessionTrackerServerId
```
public void setCreateSessionTrackerServerId(int newId)
```
    Change the server ID used by createSessionTracker(). Must be called prior to startup() being called
    
    Parameters:
    
    newId - ID to use
  - createSessionTracker
```
protected void createSessionTracker()
```
  - startSessionTracker
```
protected void startSessionTracker()
```
  - setState
```
protected void setState(ZooKeeperServer.State state)
```
    Sets the state of ZooKeeper server. After changing the state, it notifies the server state change to a registered shutdown handler, if any.
    The following are the server state transitions:
  - During startup the server will be in the INITIAL state.
  - After successfully starting, the server sets the state to RUNNING.
  - The server transitions to the ERROR state if it hits an internal error. ZooKeeperServerListenerImpl notifies any critical resource error events, e.g., SyncRequestProcessor not being able to write a txn to disk.
  - During shutdown the server sets the state to SHUTDOWN, which corresponds to the server not running.

Parameters:: state - new server state.

canShutdown
```
protected boolean canShutdown()
```
This can be used while shutting down the server to see whether the server is already shutdown or not.

Returns:

true if the server is running or server hits an error, false otherwise.

isRunning
```
public boolean isRunning()
```
Returns:

true if the server is running, false otherwise.

shutdown
```
public void shutdown()
```

shutdown
```
public void shutdown(boolean fullyShutDown)
```
Shut down the server instance

Parameters:

fullyShutDown - true if another server using the same database will not replace this one in the same process

unregisterJMX
```
protected void unregisterJMX()
```

incInProcess
```
public void incInProcess()
```

decInProcess
```
public void decInProcess()
```

getInProcess
```
public int getInProcess()
```

checkPasswd

protected boolean checkPasswd(long sessionId,
                              byte[] passwd)

setOwner

public void setOwner(long id,
                     Object owner)
              throws KeeperException.SessionExpiredException

set the owner of this session as owner

Parameters:: id - the session id; owner - the owner of the session
Throws:: KeeperException.SessionExpiredException

revalidateSession

protected void revalidateSession(ServerCnxn cnxn,
                                 long sessionId,
                                 int sessionTimeout)
                          throws IOException

Throws:: IOException

reopenSession

public void reopenSession(ServerCnxn cnxn,
                          long sessionId,
                          byte[] passwd,
                          int sessionTimeout)
                   throws IOException

Throws:: IOException

finishSessionInit

public void finishSessionInit(ServerCnxn cnxn,
                              boolean valid)

closeSession

public void closeSession(ServerCnxn cnxn,
                         RequestHeader requestHeader)

getServerId
```
public long getServerId()
```
Specified by:

getServerId in interface SessionTracker.SessionExpirer

setLocalSessionFlag
```
protected void setLocalSessionFlag(Request si)
```
If the underlying Zookeeper server support local session, this method will set a isLocalSession to true if a request is associated with a local session.

Parameters:

si -

submitRequest

public void submitRequest(Request si)

getSnapCount
```
public static int getSnapCount()
```

getGlobalOutstandingLimit

public int getGlobalOutstandingLimit()

setServerCnxnFactory

public void setServerCnxnFactory(ServerCnxnFactory factory)

getServerCnxnFactory

public ServerCnxnFactory getServerCnxnFactory()

getSecureServerCnxnFactory

public ServerCnxnFactory getSecureServerCnxnFactory()

setSecureServerCnxnFactory

public void setSecureServerCnxnFactory(ServerCnxnFactory factory)

getLastProcessedZxid
```
public long getLastProcessedZxid()
```
return the last proceesed id from the datatree

Specified by:

getLastProcessedZxid in interface ServerStats.Provider

getOutstandingRequests
```
public long getOutstandingRequests()
```
return the outstanding requests in the queue, which havent been processed yet

Specified by:

getOutstandingRequests in interface ServerStats.Provider

getNumAliveConnections
```
public int getNumAliveConnections()
```
return the total number of client connections that are alive to this server

Specified by:

getNumAliveConnections in interface ServerStats.Provider

truncateLog
```
public void truncateLog(long zxid)
                 throws IOException
```
trunccate the log to get in sync with others if in a quorum

Parameters:

zxid - the zxid that it needs to get in sync with others

Throws:

IOException

getTickTime
```
public int getTickTime()
```

setTickTime

public void setTickTime(int tickTime)

getMinSessionTimeout
```
public int getMinSessionTimeout()
```

setMinSessionTimeout

public void setMinSessionTimeout(int min)

getMaxSessionTimeout
```
public int getMaxSessionTimeout()
```

setMaxSessionTimeout

public void setMaxSessionTimeout(int max)

getClientPort
```
public int getClientPort()
```

getSecureClientPort
```
public int getSecureClientPort()
```

getMaxClientCnxnsPerHost
```
public int getMaxClientCnxnsPerHost()
```
Maximum number of connections allowed from particular host (ip)

setTxnLogFactory

public void setTxnLogFactory(FileTxnSnapLog txnLog)

getTxnLogFactory

public FileTxnSnapLog getTxnLogFactory()

getTxnLogElapsedSyncTime
```
public long getTxnLogElapsedSyncTime()
```
Returns the elapsed sync of time of transaction log in milliseconds.

getState
```
public String getState()
```
Specified by:

getState in interface ServerStats.Provider

dumpEphemerals

public void dumpEphemerals(PrintWriter pwriter)

getEphemerals

public Map<Long,Set<String>> getEphemerals()

processConnectRequest

public void processConnectRequest(ServerCnxn cnxn,
                                  ByteBuffer incomingBuffer)
                           throws IOException

Throws:: IOException

shouldThrottle

public boolean shouldThrottle(long outStandingCount)

processPacket

public void processPacket(ServerCnxn cnxn,
                          ByteBuffer incomingBuffer)
                   throws IOException

Throws:: IOException

processTxn

public DataTree.ProcessTxnResult processTxn(TxnHeader hdr,
                                            Record txn)

processTxn

public DataTree.ProcessTxnResult processTxn(Request request)

getSessionExpiryMap

public Map<Long,Set<Long>> getSessionExpiryMap()

Class ZooKeeperServer

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG

jmxServerBean

jmxDataTreeBean

DEFAULT_TICK_TIME

tickTime

minSessionTimeout

maxSessionTimeout

sessionTracker

ok

firstProcessor

state

serverCnxnFactory

secureServerCnxnFactory

Constructor Detail

ZooKeeperServer

ZooKeeperServer

ZooKeeperServer

ZooKeeperServer

ZooKeeperServer

Method Detail

serverStats

dumpConf

getConf

getZKDatabase

setZKDatabase

loadData

takeSnapshot

getDataDirSize

getLogDirSize

getZxid

getSessionTracker

setZxid

closeSession

killSession

expire

registerJMX

startdata

startup

setupRequestProcessors

getZooKeeperServerListener

setCreateSessionTrackerServerId

createSessionTracker

startSessionTracker

setState

canShutdown

isRunning

shutdown

shutdown

unregisterJMX

incInProcess

decInProcess

getInProcess

checkPasswd

setOwner

revalidateSession

reopenSession

finishSessionInit

closeSession

getServerId

setLocalSessionFlag

submitRequest

getSnapCount

getGlobalOutstandingLimit

setServerCnxnFactory

getServerCnxnFactory

getSecureServerCnxnFactory

setSecureServerCnxnFactory

getLastProcessedZxid

getOutstandingRequests

getNumAliveConnections

truncateLog

getTickTime

setTickTime