Class NIOServerCnxnFactory

java.lang.Object
org.apache.zookeeper.server.ServerCnxnFactory
org.apache.zookeeper.server.NIOServerCnxnFactory
Direct Known Subclasses:
ControllableConnectionFactory

public class NIOServerCnxnFactory extends ServerCnxnFactory
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.