org.qbroker.node

Class EventCorrelator

java.lang.Object

org.qbroker.node.Node

org.qbroker.node.EventCorrelator

All Implemented Interfaces:

MessageNode

public class EventCorrelator
extends Node

EventCorrelator converts incoming JMS messages into JMSEvents and correlates them according to their content and the predefined rulesets. All the events are correlated into non-overlapped groups based on sessions. EventCorrelator then creates a summary event for each of the groups. The summary event will be routed to the outlink of done. All the incoming events will be routed to one of three outlinks: nohit for those events do not belong to any rulesets, failure for the events failed in the correlation process and bypass for those events participated in correlations. However, the outlink of done can be shared with other outlinks. Since EventCorrelator does not consume any events, any in-coming events has to find a way out via one of the three outlinks.

EventCorrelator contains a number of predefined rulesets. These rulesets are used to categorize events into groups. It defines an EventFilter for selecting events and an EventMerger for building a summary event on the events of the group. An event may belong to multiple groups initially. The correlation process will decide its final ownership based on the size of the groups. The group with the largest size will own all the events in the group exclusively. In case there is a tie between two groups, the group with the lowest rule ID will be the winner. Therefore each ruleset defines a unique event group. The ruleset also defines a summary list for the merger to generate a new event and to attach the summary of all the events in the group. All the summary events will get formatted if the post formatter is defined in their rulesets.

EventCorrelator always creates two extra rulesets. The first one is nohit ruleset for those events without any matches. The other is candidate ruleset for all incoming events hitting at least one matches. Since there is no way to figure out the final groupships of candidate events before the correlation, they will be put into candidate group for tracking. Please remember, candidate events may not necessarily contribute to any summary events. The summary events will be counted by their own rulesets. Their property displaying and resetting are mutual-exclusively determined by the DisplayMask and StringProperty of their own rulesets. If DisplayMask is not defined in a rule or it is set to 0 or -1 (default), its StringProperty will be used to reset the string properties on the summary events. Otherwise, its StringProperty will only be used to display the details of summary events. On the node level, DisplayMask and StringProperty control the displaying result of all candidate events. If the DisplayMask of a ruleset is set to -1, that rule will inherit the DisplayMask and the StringProperty from the node for display control on the rule level.

It is OK to have a bypass ruleset without any EventMerger. Any ruleset with PreferredOutLink defined is called bypass ruleset. If a bypass ruleset matches an event, the event will be routed to the specified outlink directly, bypassing rest of the correlation process. It is acting like a jump out of the loop.

You are free to choose any names for the four fixed outlinks. But EventCorrelator always assumes the first outlink for done, the second for bypass, the third for failure and the last for nohit. Any two or more outlinks can share the same outlink name. It means these outlinks are sharing the same output channel.

Author:

yannanlu@yahoo.com

Field Summary

Fields inherited from class org.qbroker.node.Node

assetList, bufferSize, callbackMethod, capacity, cbw, cells, cfgList, chkptExpiration, debug, DEBUG_COLL, DEBUG_DIFF, DEBUG_FBAK, DEBUG_INIT, DEBUG_PASS, DEBUG_PROP, DEBUG_REPT, DEBUG_UPDT, displayMask, displayPropertyName, linkName, LOAD_HIGH, LOAD_LOW, LOAD_MEDIUM, msgList, name, operation, RESET_ALL, RESET_MAP, RESET_NONE, RESET_SOME, ruleList, status, TYPE_ACTION, TYPE_AGGREGATE, TYPE_BYPASS, TYPE_CACHE, TYPE_COLLECT, TYPE_DELIVER, TYPE_FORMAT, TYPE_JSONPATH, TYPE_JSONT, TYPE_MAPREDUCE, TYPE_NONE, TYPE_PARSER, TYPE_PICKUP, TYPE_PIPE, TYPE_PUBLISH, TYPE_ROUNDROBIN, TYPE_SCREEN, TYPE_SCRIPT, TYPE_SERVICE, TYPE_SORT, TYPE_SPLIT, TYPE_SPREAD, TYPE_WEIGHTED, TYPE_XPATH, TYPE_XSLT, waitTime, xaMode

Fields inherited from interface org.qbroker.node.MessageNode

ASSET_THR, ASSET_URI, ASSET_XQ, META_MAP, META_MSG, META_OUT, META_RULE, META_XQ, MSG_BID, MSG_CID, MSG_OID, MSG_RID, MSG_TID, MSG_TIME, NODE_CLOSED, NODE_DISABLED, NODE_PAUSE, NODE_READY, NODE_RETRYING, NODE_RUNNING, NODE_STANDBY, NODE_STOPPED, OUT_CAPACITY, OUT_COUNT, OUT_DEQ, OUT_EXTRA, OUT_LENGTH, OUT_MODE, OUT_NRULE, OUT_OFFSET, OUT_ORULE, OUT_QDEPTH, OUT_QIPPS, OUT_QSTATUS, OUT_QTIME, OUT_SIZE, OUT_STATUS, OUT_TIME, RULE_COUNT, RULE_DMASK, RULE_EXTRA, RULE_GID, RULE_MODE, RULE_OID, RULE_OPTION, RULE_PEND, RULE_PID, RULE_SIZE, RULE_STATUS, RULE_TIME, RULE_TTL

Constructor Summary

Constructors

Constructor and Description
EventCorrelator(java.util.Map props)

Method Summary

Modifier and Type	Method and Description
void	close() It closes all resources and cleans up all list, cache, metadata, etc.
protected void	finalize()
protected java.util.Map<java.lang.String,java.lang.Object>	initRuleset(long tm, java.util.Map ph, long[] ruleInfo) It initializes a new ruleset with the ruleInfo and returns the rule upon success.
void	propagate(XQueue in, XQueue[] out) picks up a message from input queue and evaluates its content to decide which output queue to propagate
int	removeRule(java.lang.String key, XQueue in) It removes the rule from the ruleList and returns the rule id upon success.
int	replaceRule(java.lang.String key, java.util.Map ph, XQueue in) It replaces the existing rule of the key and returns its id upon success.
int	updateParameters(java.util.Map props) It updates the parameters of the node with the given property map.

Methods inherited from class org.qbroker.node.Node

addRule, callback, checkpoint, collectAll, containsRule, containsXQ, feedback, forcethru, getCapacity, getCapacity, getDebugMode, getDisplayMask, getDisplayProperties, getLinkName, getLinkName, getMetaData, getName, getNumberOfOutLinks, getNumberOfRules, getOperation, getOutLinkBoundary, getRuleName, getStatus, getXAMode, getXAMode, internalXQSupported, list, listPendings, passthru, refreshRule, renameRule, resetMetaData, restore, rotateRule, setDebugMode, setDisplayMask, setDisplayProperties, setStatus, show, takeback, takebackEnabled

Methods inherited from class java.lang.Object

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

Constructor Detail

EventCorrelator

public EventCorrelator(java.util.Map props)

Method Detail

updateParameters

public int updateParameters(java.util.Map props)

Description copied from class: Node

It updates the parameters of the node with the given property map. Upon success, it returns the number of parameters modified. It is not MT-Safe.

Specified by:

updateParameters in interface MessageNode

Overrides:

updateParameters in class Node

initRuleset

protected java.util.Map<java.lang.String,java.lang.Object> initRuleset(long tm,
                                                                       java.util.Map ph,
                                                                       long[] ruleInfo)

It initializes a new ruleset with the ruleInfo and returns the rule upon success. Otherwise, it throws an exception or returns null.

Specified by:

initRuleset in class Node

removeRule

public int removeRule(java.lang.String key,
                      XQueue in)

It removes the rule from the ruleList and returns the rule id upon success. It is not MT-Safe. There is no RULE_SIZE checking.

Specified by:

removeRule in interface MessageNode

Overrides:

removeRule in class Node

replaceRule

public int replaceRule(java.lang.String key,
                       java.util.Map ph,
                       XQueue in)

It replaces the existing rule of the key and returns its id upon success. It is not MT-Safe.

Specified by:

replaceRule in interface MessageNode

Overrides:

replaceRule in class Node

propagate

public void propagate(XQueue in,
                      XQueue[] out)
               throws javax.jms.JMSException

picks up a message from input queue and evaluates its content to decide which output queue to propagate

Specified by:

propagate in interface MessageNode

Specified by:

propagate in class Node

Throws:

javax.jms.JMSException

close

public void close()

Description copied from class: Node

It closes all resources and cleans up all list, cache, metadata, etc. Once it is closed, it can not be used any more.

Specified by:

close in interface MessageNode

Overrides:

close in class Node

finalize

protected void finalize()

Overrides:

finalize in class Node