org.dataone.client.utils

Class HttpConnectionMonitorService

java.lang.Object

java.lang.Thread

org.dataone.client.utils.HttpConnectionMonitorService

All Implemented Interfaces:

Runnable

public class HttpConnectionMonitorService
extends Thread

A Service class that monitors HttpClient ConnectionManagers for stale (idle and expired) connections and removes them to free up system resources (sockets). Because HttpClients only close their end of a socket when they discover the socket closed upon the next request, the only two reliable ways to release sockets are to (a) monitor their ConnectionManagers in a separate thread, and to (b) actively shutdown the ConnectionManager or close the HttpClient.

The D1Client facades hide HttpClients from users, so this class is also used to actively shutdown all of the instantiated and registered ConnectionManagers at the interruption of it's run() method.

Assuming that this thread runs for the duration of the application run, this ensures that sockets created and not stale get released when the program exits.

Author:

rnahf

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Method Summary

Modifier and Type	Method and Description
void	addHttpClientMonitor(org.apache.http.client.HttpClient client) Add an HttpClient to close upon exit.
void	addMonitor(org.apache.http.conn.HttpClientConnectionManager cMan) Add a connectionManager to monitor
static HttpConnectionMonitorService	getInstance()
void	removeMonitor(org.apache.http.conn.HttpClientConnectionManager cMan) remove a ConnectionManager from monitoring Not sure of the use case for it, since we need to keep all of the ConnectionManagers around until application shutdown, where-upon we close all connection managers.
void	run()
protected void	shutdownConnectionManagers()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static HttpConnectionMonitorService getInstance()

addMonitor

public void addMonitor(org.apache.http.conn.HttpClientConnectionManager cMan)

Add a connectionManager to monitor

Parameters:

cMan -

addHttpClientMonitor

public void addHttpClientMonitor(org.apache.http.client.HttpClient client)

Add an HttpClient to close upon exit. HttpClients don't give access to the ConnectionManager, so we cannot close stale connections, but we can call close() upon exit, to release system resources.

Parameters:

client -

removeMonitor

public void removeMonitor(org.apache.http.conn.HttpClientConnectionManager cMan)

remove a ConnectionManager from monitoring Not sure of the use case for it, since we need to keep all of the ConnectionManagers around until application shutdown, where-upon we close all connection managers.

Parameters:

cMan -

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

shutdownConnectionManagers

protected void shutdownConnectionManagers()