Package org.apache.zookeeper.server
Class NIOServerCnxnFactory
java.lang.Object
org.apache.zookeeper.server.ServerCnxnFactory
org.apache.zookeeper.server.NIOServerCnxnFactory
- Direct Known Subclasses:
ControllableConnectionFactory
NIOServerCnxnFactory implements a multi-threaded ServerCnxnFactory using
NIO non-blocking socket calls. Communication between threads is handled via
queues.
- 1 accept thread, which accepts new connections and assigns to a
selector thread
- 1-N selector threads, each of which selects on 1/N of the connections.
The reason the factory supports more than one selector thread is that
with large numbers of connections, select() itself can become a
performance bottleneck.
- 0-M socket I/O worker threads, which perform basic socket reads and
writes. If configured with 0 worker threads, the selector threads
do the socket I/O directly.
- 1 connection expiration thread, which closes idle connections; this is
necessary to expire connections on which no session is established.
Typical (default) thread counts are: on a 32 core machine, 1 accept thread,
1 connection expiration thread, 4 selector threads, and 64 worker threads.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionclass
The SelectorThread receives newly accepted connections from the AcceptThread and is responsible for selecting for I/O readiness across the connections. -
Field Summary
FieldsModifier and TypeFieldDescriptionprotected int
protected WorkerService
static final String
Default: 64kBstatic final String
With 500 connections to an observer with watchers firing on each, is unable to exceed 1GigE rates with only 1 selector.static final String
Default: 2 * numCoresstatic final String
Default sessionless connection timeout in ms: 10000 (10s)static final String
Default worker pool shutdown timeout in ms: 5000 (5s)Fields inherited from class org.apache.zookeeper.server.ServerCnxnFactory
cnxns, login, maxCnxns, saslServerCallbackHandler, secure, zkServer, ZOOKEEPER_MAX_CONNECTION_DEFAULT, ZOOKEEPER_SERVER_CNXN_FACTORY
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Constructor Summary
ConstructorsConstructorDescriptionConstruct a new server connection factory which will accept an unlimited number of concurrent connections from each client (up to the file descriptor limits of the operating system). -
Method Summary
Modifier and TypeMethodDescriptionvoid
closeAll
(ServerCnxn.DisconnectReason reason) clear all the connections in the selectorvoid
configure
(InetSocketAddress addr, int maxcc, int backlog, boolean secure) protected NIOServerCnxn
createConnection
(SocketChannel sock, SelectionKey sk, NIOServerCnxnFactory.SelectorThread selectorThread) void
dumpConnections
(PrintWriter pwriter) getAllConnectionInfo
(boolean brief) static ByteBuffer
int
int
Maximum number of connections allowed from particular host (ip)int
The maximum queue length of the ZooKeeper server's socketvoid
join()
void
reconfigure
(InetSocketAddress addr) boolean
removeCnxn
(NIOServerCnxn cnxn) De-registers the connection from the various mappings maintained by the factory.void
void
setMaxClientCnxnsPerHost
(int max) Maximum number of connections allowed from particular host (ip)void
shutdown()
void
start()
void
startup
(ZooKeeperServer zks, boolean startServer) void
stop()
void
touchCnxn
(NIOServerCnxn cnxn) Add or update cnxn in our cnxnExpiryQueueMethods inherited from class org.apache.zookeeper.server.ServerCnxnFactory
addSession, closeSession, configure, configure, configureSaslLogin, createFactory, createFactory, createFactory, createFactory, createFactory, getMaxCnxns, getNumAliveConnections, getUserName, getZooKeeperServer, initMaxCnxns, isSecure, limitTotalNumberOfCnxns, registerConnection, removeCnxnFromSessionMap, setZooKeeperServer, startup, unregisterConnection
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Field Details
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ZOOKEEPER_NIO_SESSIONLESS_CNXN_TIMEOUT
Default sessionless connection timeout in ms: 10000 (10s)- See Also:
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ZOOKEEPER_NIO_NUM_SELECTOR_THREADS
With 500 connections to an observer with watchers firing on each, is unable to exceed 1GigE rates with only 1 selector. Defaults to using 2 selector threads with 8 cores and 4 with 32 cores. Expressed as sqrt(numCores/2). Must have at least 1 selector thread.- See Also:
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ZOOKEEPER_NIO_NUM_WORKER_THREADS
Default: 2 * numCores- See Also:
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ZOOKEEPER_NIO_DIRECT_BUFFER_BYTES
Default: 64kB- See Also:
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ZOOKEEPER_NIO_SHUTDOWN_TIMEOUT
Default worker pool shutdown timeout in ms: 5000 (5s)- See Also:
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maxClientCnxns
protected int maxClientCnxns -
workerPool
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Constructor Details
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NIOServerCnxnFactory
public NIOServerCnxnFactory()Construct a new server connection factory which will accept an unlimited number of concurrent connections from each client (up to the file descriptor limits of the operating system). startup(zks) must be called subsequently.
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Method Details
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getDirectBuffer
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configure
public void configure(InetSocketAddress addr, int maxcc, int backlog, boolean secure) throws IOException - Specified by:
configure
in classServerCnxnFactory
- Throws:
IOException
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reconfigure
- Specified by:
reconfigure
in classServerCnxnFactory
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getMaxClientCnxnsPerHost
public int getMaxClientCnxnsPerHost()Maximum number of connections allowed from particular host (ip)- Specified by:
getMaxClientCnxnsPerHost
in classServerCnxnFactory
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setMaxClientCnxnsPerHost
public void setMaxClientCnxnsPerHost(int max) Maximum number of connections allowed from particular host (ip)- Specified by:
setMaxClientCnxnsPerHost
in classServerCnxnFactory
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getSocketListenBacklog
public int getSocketListenBacklog()The maximum queue length of the ZooKeeper server's socket- Specified by:
getSocketListenBacklog
in classServerCnxnFactory
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start
public void start()- Specified by:
start
in classServerCnxnFactory
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startup
public void startup(ZooKeeperServer zks, boolean startServer) throws IOException, InterruptedException - Specified by:
startup
in classServerCnxnFactory
- Throws:
IOException
InterruptedException
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getLocalAddress
- Specified by:
getLocalAddress
in classServerCnxnFactory
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getLocalPort
public int getLocalPort()- Specified by:
getLocalPort
in classServerCnxnFactory
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removeCnxn
De-registers the connection from the various mappings maintained by the factory. -
touchCnxn
Add or update cnxn in our cnxnExpiryQueue- Parameters:
cnxn
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createConnection
protected NIOServerCnxn createConnection(SocketChannel sock, SelectionKey sk, NIOServerCnxnFactory.SelectorThread selectorThread) throws IOException - Throws:
IOException
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closeAll
clear all the connections in the selector- Specified by:
closeAll
in classServerCnxnFactory
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stop
public void stop() -
shutdown
public void shutdown()- Specified by:
shutdown
in classServerCnxnFactory
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join
- Specified by:
join
in classServerCnxnFactory
- Throws:
InterruptedException
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getConnections
- Specified by:
getConnections
in classServerCnxnFactory
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dumpConnections
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resetAllConnectionStats
public void resetAllConnectionStats()- Specified by:
resetAllConnectionStats
in classServerCnxnFactory
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getAllConnectionInfo
- Specified by:
getAllConnectionInfo
in classServerCnxnFactory
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