Package org.cometd.oort

Class OortMulticastConfigServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.cometd.oort.OortConfigServlet

org.cometd.oort.OortMulticastConfigServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class OortMulticastConfigServlet
extends OortConfigServlet

This servlet initializes and configures an instance of the Oort CometD cluster manager via autodiscovery of other Oort comets using UDP multicast.

This servlet configures and starts an instance of OortMulticastConfigurer that advertises via multicast the Oort URL to which it is associated and receives the advertisements from other Oort comets.

This servlet must be initialized after an instance the CometD servlet that creates the BayeuxServer instance used by Oort.

This servlet inherits from OortConfigServlet init parameters used to configure the Oort instance, and adds the following init parameters:

• oort.multicast.bindAddress, to specify the bind address of the MulticastSocket that receives the advertisements; defaults to the wildcard address
• oort.multicast.groupAddress, to specify the multicast group address to join to receive the advertisements; defaults to 239.255.0.1
• oort.multicast.groupPort, to specify the port over which advertisements are sent and received; defaults to 5577
• oort.multicast.groupInterfaces, a comma separated list of IP addresses that will join the multicast group; default to all interfaces that support multicast
• oort.multicast.timeToLive, to specify the time to live of advertisement packets; defaults to 1 (1 = same subnet, 32 = same site, 255 = global)
• oort.multicast.advertiseInterval, to specify the interval in milliseconds at which advertisements are sent; defaults to 2000 ms
• oort.multicast.connectTimeout, to specify the timeout in milliseconds that a node should wait to connect to another node; defaults to 2000 ms
• oort.multicast.maxTransmissionLength, to specify the maximum length in bytes of the advertisement message, and should be smaller than the max transmission unit; defaults to 1400 bytes

See Also:

OortConfigServlet, OortMulticastConfigServlet, Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static String	OORT_MULTICAST_ADVERTISE_INTERVAL_PARAM
static String	OORT_MULTICAST_BIND_ADDRESS_PARAM
static String	OORT_MULTICAST_CONNECT_TIMEOUT_PARAM
static String	OORT_MULTICAST_GROUP_ADDRESS_PARAM
static String	OORT_MULTICAST_GROUP_INTERFACES_PARAM
static String	OORT_MULTICAST_GROUP_PORT_PARAM
static String	OORT_MULTICAST_MAX_TRANSMISSION_LENGTH_PARAM
static String	OORT_MULTICAST_TIME_TO_LIVE_PARAM

Fields inherited from class org.cometd.oort.OortConfigServlet

LOG, OORT_CHANNELS_PARAM, OORT_ENABLE_ACK_EXTENSION_PARAM, OORT_ENABLE_BINARY_EXTENSION_PARAM, OORT_JSON_CONTEXT_PARAM, OORT_SECRET_PARAM, OORT_URL_PARAM

Constructor Summary

Constructors

Constructor	Description
OortMulticastConfigServlet()

Method Summary

Modifier and Type	Method	Description
protected void	configureCloud(javax.servlet.ServletConfig config, Oort oort)	Configures the Oort cloud by establishing connections with other Oort comets.
void	destroy()

Methods inherited from class org.cometd.oort.OortConfigServlet

configureOort, init, newOort, provideOortURL

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Field Detail

OORT_MULTICAST_BIND_ADDRESS_PARAM

public static final String OORT_MULTICAST_BIND_ADDRESS_PARAM

See Also:

Constant Field Values

OORT_MULTICAST_GROUP_ADDRESS_PARAM

public static final String OORT_MULTICAST_GROUP_ADDRESS_PARAM

See Also:

Constant Field Values

OORT_MULTICAST_GROUP_PORT_PARAM

public static final String OORT_MULTICAST_GROUP_PORT_PARAM

See Also:

Constant Field Values

OORT_MULTICAST_GROUP_INTERFACES_PARAM

public static final String OORT_MULTICAST_GROUP_INTERFACES_PARAM

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Constant Field Values

OORT_MULTICAST_TIME_TO_LIVE_PARAM

public static final String OORT_MULTICAST_TIME_TO_LIVE_PARAM

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Constant Field Values

OORT_MULTICAST_ADVERTISE_INTERVAL_PARAM

public static final String OORT_MULTICAST_ADVERTISE_INTERVAL_PARAM

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Constant Field Values

OORT_MULTICAST_CONNECT_TIMEOUT_PARAM

public static final String OORT_MULTICAST_CONNECT_TIMEOUT_PARAM

See Also:

Constant Field Values

OORT_MULTICAST_MAX_TRANSMISSION_LENGTH_PARAM

public static final String OORT_MULTICAST_MAX_TRANSMISSION_LENGTH_PARAM

See Also:

Constant Field Values

Constructor Detail

OortMulticastConfigServlet

public OortMulticastConfigServlet()

Method Detail

configureCloud

protected void configureCloud(javax.servlet.ServletConfig config,
                              Oort oort)
                       throws Exception

Description copied from class: OortConfigServlet

Configures the Oort cloud by establishing connections with other Oort comets.

Subclasses implement their own strategy to discover and link with other comets.

Specified by:

configureCloud in class OortConfigServlet

Parameters:

config - the servlet configuration to read parameters from

oort - the Oort instance associated with this configuration servlet

Throws:

Exception - if the cloud configuration fails

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class OortConfigServlet