org.qbroker.node

Class EventMonitor

java.lang.Object

org.qbroker.node.Node

org.qbroker.node.EventMonitor

All Implemented Interfaces:

MessageNode

public class EventMonitor
extends Node

EventMonitor monitors incoming JMS events and keeps tracking their state according to the rulesets and the value of the aggregated attribute. In case that the state changes up to a certain point, EventMonitor will generate a new JMS event as the escalation. All escalation events will be routed to the outlink of done. For all the incoming events, EventMonitor routes them into three outlinks: bypass for all the processed incoming events, nohit for those events do not belong to any rulesets, failure for the incoming events failed in the process. However, the outlink of done can be shared with other outlinks.

EventMonitor contains a number of predefined rulesets. These rulesets categorize incoming events into non-overlapping groups. Therefore, each ruleset defines a unique event group. It contains the name of the rule, and an EventSelector to select events for the group. If PreferredOutLink is defined in the ruleset, it is treated as a bypass ruleset. Otherwise, it will be treated as an escalation ruleset that may generate extra messages. For those escalation messages, they will get formatted if the post formatter is defined in their rulesets.

For each incomiong event, EventMonitor will match it against every EventSelectors to single out a ruleset. There are two cases for escalation rulesets. If ClassName is defined in a ruleset, it will be used to instantiate an instance of EventEscalation. Otherwise, it is the timeout escalation ruleset in which EventMonitor expects certain events showing up frequently. If a ruleset of EventEscalation is selected, EventMonitor will invoke its public method of escalate() to evalaute the event. The instance of EventEscalation is supposed to maintain the state for the event group. In case that a state change is up to certain point, an escalation event will be generated by its method of escalate(). This event will contain details of the state change. It will be delivered according to the predefined EscalationOrder with the value of either "first", "last" or "none" for no order preference. In case of "first" or "last", the ruleset also allows ActionDelay defined in millisec. In case of the ruleset of "last", it specifies how long the escalation gets delayed. For the ruleset of "first", the delay happens after the escalation. EscalationMask controls the display mask on escalation messages.

In case of a ruleset for timeout escalations, KeyTemplate is required to be defined so that EventMonitor is able cache the properties of the incoming event with the unique key for a new state or update the timestamp of an existing state with the incoming event. The ruleset expects certain events kept coming to keep it up to date. If the expected event has not shown up within a given interval, an escalation event will be generated as the escalation with the priority set to EscalationPriority. A list of attribute names is specified in CopiedProperty. Those attributes cached from the first incoming event will be copied to the escalation event. The tracking session for an existing state can be terminated or reset by an event whose priority is same as the predefined ResetPriority of the ruleset. The timeout escalation ruleset is good to track those alerts fired only once.

EventMonitor always creates one extra ruleset, nohit. The ruleset of nohit is for those events not hitting any patterns. Its RULE_PEND field is used to store the total number of cached states for all timeout rulesets. Please remember that there is no one-to-one relationship between the candidate events and the esacaltion events. The total number of escalation events for a ruleset is stored into its RULE_PEND field.

You are free to choose any names for the four fixed outlinks. But EventMonitor 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
EventMonitor(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 int	feedback(XQueue in, long milliSec) It returns the number of done messages removed from the input XQueue.
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.
protected int	passthru(long currentTime, javax.jms.Message msg, XQueue in, int rid, int oid, int cid, int tid) It passes the message from the input XQueue over to an output XQueue and returns 1 upon success or 0 otherwise.
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.
void	resetMetaData(XQueue in, XQueue[] out) cleans up MetaData for all XQs and messages
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, forcethru, getCapacity, getCapacity, getDebugMode, getDisplayMask, getDisplayProperties, getLinkName, getLinkName, getMetaData, getName, getNumberOfOutLinks, getNumberOfRules, getOperation, getOutLinkBoundary, getRuleName, getStatus, getXAMode, getXAMode, internalXQSupported, list, listPendings, refreshRule, renameRule, 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

EventMonitor

public EventMonitor(java.util.Map props)

Method Detail

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

passthru

protected int passthru(long currentTime,
                       javax.jms.Message msg,
                       XQueue in,
                       int rid,
                       int oid,
                       int cid,
                       int tid)

It passes the message from the input XQueue over to an output XQueue and returns 1 upon success or 0 otherwise. In case of cid is less than 0, the message has nothing to do with the input XQueue. Nothing will be added to msgList for tracking. No callbacks and no update on rule stats either. If tid is less than 0, msg will not be put back to uplink in case of failure. There is no update on rule stats and no callbacks either. In case of cid is larger than or equal to 0 and tid is less than 0, it will add msg stats to msgList for external tracking. But the end user has to clean it up after the usage since it is not collectible by feedback() without the callback.

Overrides:

passthru in class Node

feedback

protected int feedback(XQueue in,
                       long milliSec)

It returns the number of done messages removed from the input XQueue. If milliSec is less than 0, there is no wait and it tries to collect all cells. Otherwise, it just tries to collect the first collectible cell.

Overrides:

feedback in class Node

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

resetMetaData

public void resetMetaData(XQueue in,
                          XQueue[] out)

cleans up MetaData for all XQs and messages

Specified by:

resetMetaData in interface MessageNode

Overrides:

resetMetaData in class Node

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