Event and Alarm handling Application(EVA) - Erlang

68 Pages·2002·0.24 MB·English

Event and Alarm handling
Application(EVA)
version 2.0
TypesetinLATEXfromSGMLsourceusingtheDOCBUILDER3.2.2DocumentSystem.
Contents
1 EVAUser’sGuide 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 BasicEventandAlarmService. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.2 LogControlService . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.3 EVALogService . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3 EVAAdaptations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3.1 Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 EVASNMPIinterface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.4.1 EVASNMPAdaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.4.2 LOGSNMPInterface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.4.3 EVA-LOGSNMPInterface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.4.4 SNMPEALOGSNMPInterface . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.5 AppendixA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.5.1 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.6 EVAReleaseNotes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.6.1 EVA-EventandAlarmHandlerv2.0.2.1 . . . . . . . . . . . . . . . . . . . . . 23
1.6.2 EVA-EventandAlarmHandlerv2.0.2. . . . . . . . . . . . . . . . . . . . . . . 23
1.6.3 EVA2.0.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1.6.4 EVA2.0.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1.6.5 EVA1.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2 EVAReferenceManual 27
2.1 eva . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.2 eva . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.3 eva log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.4 eva server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.5 eva sup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.6 log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.7 log server. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
EventandAlarmhandlingApplication(EVA) iii
3 EVAReferenceManual-SNMPadaptation 47
3.1 eva log snmp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.2 eva snmp adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.3 log snmp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.4 log snmpea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Glossary 59
iv EventandAlarmhandlingApplication(EVA)
Chapter 1
EVA User’s Guide
TheEventandAlarmHandlingapplication,EVAisanoperationandmaintenance applicationinthe
faultmanagementarea. Itcontainssupportforapplicationstosendeventsandalarmsandcreatelogs. It
providesmanagersfunctionsforcontrollingtheeventsandalarmsandcontrollingthelogs.
EVAisamanagementprotocolindependentapplicationthatneedsprotocoladaptationsto
communicatewitharemotemanager. Currently,onesuchadaptationforSNMPisincludedinEVA.
1.1 Introduction
Theoperationandmaintenance supportinOTPconsistsofagenericmodelformanagement
subsystemsinOTP,andsomecomponentstobeusedinthesesubsystems. Themodelthatthissupport
isbaseduponisdescribedin“OAMPrinciples”.
Thisdocumentdescribesoneofthesecomponents,theFaultManagementapplicationEVA.EVA
consistsofsupportforEventandAlarmHandlingandsupportforgenericLogControl.
EVAisamodularapplicationthatconsistsoftwomanagementprotocolindependentservices. It
containsalsorulesandfunctionsfordefiningprotocoladaptationsforEVA.Onesuchadaptationis
includedforSNMP.ItconsistsofSNMPMIBsandimplementationoftheseMIBs.
EVAusestheapplicationsMnesiaandSASL.
1.1.1 Architecture
EVAisasubapplicationthatcanbeincludedintoanotherapplication. Itisdesignedtoworkasa
distributedapplication,whichmeansthatitalwaysexecutesononenode,withothernodesasstandby
nodes. EVAshouldrunonthesamenodeasotheroperationandmaintenance applications,specifically
themanagementprotocolterminationapplication,tominimizeinternalnetworktraffic.
EVAisdesignedtobeprotocolindependent,andmaybeusedwithdifferentmanagementprotocols.
Foreachsuchprotocol,anEVAadaptationmustbewritten. Forexample,wehavedefinedanSNMP
adaptation,andmoreadaptationsmaybedefinedinthefuture,e.g. forHTTP,CORBAorany
proprietaryprotocol(e.g. plainErlang).
Theeventandalarmsupportcanrunintwodifferentmodes,inserver modeandinclient mode. In
clientmode,noprocessesarerunning,butthecodeimplementingtheAPIisloaded. Theremustalways
beoneserverrunningononenodeinthenetworkofErlangnodesthatthesystemconsistsof.
ForEVA,allinvolvednodesareseenasone(distributed)system. Thismeansforexamplethatthereis
oneactivealarmlistfortheentiresystem.
EventandAlarmhandlingApplication(EVA) 1
Chapter1: EVAUser’sGuide
1.2 Services
TherearetwomanagementprotocolindependentEVAservicesprovided,thebasicEventandAlarm
serviceandtheLogControlservice. ThebasicEVAserviceprovidesclientswithanAPIforregistering
andsendingeventsandalarms. TheLogcontrolserviceprovidesamechanismforcontrolofgeneric
logs. Alsoincludedisaspecializationofthegenericlogfunctionforloggingofeventsandalarms.
Eachserviceprovidesclientfunctionsthatcanbeusedfromapplicationsinthesystemto,forexample,
sendalarms. ThereisalsoanAPIthatmanagementapplicationscanusetomonitorandcontrolthe
system. ThisAPIcanbeextendedforspecificmanagementprotocols,suchasSNMPorCORBA.
1.2.1 Basic Event and Alarm Service
ThisservicecontainsfunctionsfortheclientAPItoEVA.EVAisadistributedglobalapplication,which
meansthatclientscanaccesstheEVAfunctionalityfromanynode.
Clientscanregisterandsendeventsandalarms. Managementapplicationscansubscribetoeventand
alarms,andcontrolthetreatmentofthem.
AneventisanotificationsentfromtheNEtoamanagementapplication. Aneventisuniquely
identifiedbyitsname. Aspecialformofaneventisanalarm. Analarmrepresentsafaultinthesystem
thatneedstobereportedtothemanager. Anexampleofanalarmcouldbeequipment on fire. When
analarmissent,itbecomesactive,andisstoredinanactivealarmlist. Whentheapplicationthatsent
thealarmnoticesthatthefaultthatcausedthealarmisnotvalidanymore,itclearsthealarm. Whenan
alarmiscleared,thealarmisdeletedfromtheactivealarmlist,andanclear alarmeventisgenerated
byEVA.Eachfaultmaygiverisetoseveralalarms,maybewithdifferentseverities. Therecanhowever
onlybeoneactivealarmforeachfaultatthesametime. Forexample,associatedwithdiskspaceusage
maybetwoalarms,disk 80 percent filledanddisk 90 percent filled. Thesetwoalarms
representsthesamefault,butonlyoneofthemcanbeactiveatthesametime. Anactivealarmis
identifiedbyitsfault id. Incontrasttoalarms,ordinaryeventsdonotrepresentfaults,andarenotstored
asthealarmsintheactivealarmlist.
ThebasicEVAserverisaglobalservertowhichalleventsandalarmsaresent. Theserverupdatesits
tables(e.g. theactivealarmlist),andsendstheeventoralarmtothealarm handlerprocessthatruns
onthesamenodeastheglobalserver. alarm handlerisagen eventprocessdefinedintheSASL
application.
Beforeaclientcansendaneventoralarm,thenameoftheeventmustberegisteredinEVA.Toregister
anevent,aclientcallsregister event/2. Theparametersofthisfunctionarethenameoftheevent
andwhethertheeventshouldbeloggedbydefaultornot. Amanagercandecidetochangethisvalue
later. Toregisteranalarm,aclientcallsregister alarm/4. Theparametersofthisfunctionarethe
nameandloggingparametersasforevents,andtheclassanddefaultseverityofthealarm.
EVAstoresthedefinitionsofeventsandalarmsintheMnesiatableseventTableandalarmTable
respectively. Sinceanalarmisaspecialformofanevent,eachalarmispresentinbothofthesetables.
TheactivealarmlistisstoredintheMnesiatablealarm. Therecordsforallthesetablesaredefinedin
theheaderfileeva.hrl,availableintheincludedirectoryinthedistribution.
2 EventandAlarmhandlingApplication(EVA)
1.2: Services
EventDefinitionTable
AllregisteredeventsarestoredintheeventTable.Ithasthefollowingattributes:
name
(cid:15)
log
(cid:15)
generated
(cid:15)
Theeventisuniquelyidentifiedbyitsname,whichisanatom.
Thelogattributeisabooleanflagthattellswhetherthiseventshouldbestoredinsomelogwhenitis
generatedornot. Thisattributeiswritable.
Thegeneratedattributeisacounterthatcountshowmanytimestheeventhasbeengenerated.
AlarmDefinitionTable
ThealarmTableextendstheeventTable,andhasthefollowingattributes:
name
(cid:15)
class
(cid:15)
severity
(cid:15)
Thealarmisuniquelyidentifiedbyitsname,whichisanatom. Notethateachalarmispresentinthe
eventTableaswell.
Theclassattributecategorizesthealarm,andisdefinedwhenthealarmisregistered. Itisasdefinedin
X.733,ITUAlarmReportingFunction:
communications.Analarmofthisclassisprincipallyassociatedwiththeproceduresorprocesses
(cid:15) requiredtoconveyinformationfromonepointtoanother.
qos. Analarmofthisclassisprincipallyassociatedwithadegradationinthequalityofservice.
(cid:15)
processing.Analarmofthisclassisprincipallyassociatedwithasoftwareorprocessingfault.
(cid:15)
equipment.Analarmofthisclassisprincipallyassociatedwithanequipmentfault.
(cid:15)
environmental.Analarmofthisclassisprincipallyassociatedwithaconditionrelatingtoan
(cid:15) enclosureinwithequipmentresides.
Theseverityparameterdefinesfiveseveritylevels,whichprovideanindicationofhowitisperceived
thatthecapability ofthemanagedobjecthasbeenaffected. Thoseseveritylevelswhichrepresent
serviceaffectingconditionsorderedfrommostseveretoleastseverearecritical,major,minorand
warning. ThelevelsusedareasdefinedinX.733,ITUAlarmReportingFunction:
indeterminate.TheIndeterminateseveritylevelindicatesthattheseveritylevelcannotbe
(cid:15) determined.
critical. TheCriticalseveritylevelindicates thataserviceaffectingconditionhasoccurredand
(cid:15) animmediatecorrectiveactionisrequired. Suchaseveritycanbereported,forexample,whena
managedobjectbecomestotallyoutofserviceanditscapabilitymustberestored.
major. TheMajorseveritylevelindicatesthataserviceaffectingconditionhasdevelopedandan
(cid:15) urgentcorrectiveactionisrequired. Suchaseveritycanbereported,forexample,whenthereisa
severedegradationinthecapabilityofthemanagedobjectanditsfullcapabilitymustberestored.
EventandAlarmhandlingApplication(EVA) 3
Chapter1: EVAUser’sGuide
minor. TheMinorseveritylevelindicatestheexistenceofanon-serviceaffectingfaultcondition
(cid:15) andthatcorrectiveactionshouldbetakeninordertopreventamoreserious(forexample,service
affecting)fault. Suchaseveritycanbereported,forexample,whenthedetectedalarmcondition
isnotcurrentlydegradingthecapacity ofthemanagedobject.
warning. TheWarningseveritylevelindicates thedetectionofapotentialorimpendingservice
(cid:15) affectingfault,beforeanysignificanteffectshavebeenfelt. Actionshouldbetakentofurther
diagnose(ifnecessary)andcorrecttheprobleminordertopreventitfrombecomingamore
seriousserviceaffectingfault.
Whenanalarmiscleared,aclear alarmeventisgenerated. Thiseventclearsthealarmwiththe
fault idcontainedintheevent. Itisnotrequiredthattheclearingofpreviouslyreportedalarmsare
reported. Therefore,amanagingsystemcannotassumethattheabsenceofanclear alarmeventfora
faultmeansthattheconditionthatcausedthegenerationofpreviousalarmsisstillpresent. Managed
objectdefinersshallstateif,andunderwhichconditions,theclear alarmeventisused.
ActiveAlarmList
TheactivealarmlistisstoredintheorderedMnesiatablealarm. Thecorrespondingrecordissentto
thealarm handlerwhenanalarmissent. Ithasthefollowingread-onlyattributes:
index
(cid:15)
fault id
(cid:15)
name
(cid:15)
sender
(cid:15)
cause
(cid:15)
severity
(cid:15)
time
(cid:15)
extra
(cid:15)
Arowintheactivealarmlistisuniquelyidentifiedbyitsfault id. However,tomakethetable
ordered,thealarmsusestheintegerindexasakeyintothetable. Foreachnewalarm,EVAallocatesa
newindexthatisgreaterthantheindexofallotheractivealarms.
Thenameisthenameofthecorrespondingalarmtype,definedinalarmTable.
senderisatermthatuniquelyidentifiestheresourcethatgeneratedthealarm.
causedescribestheprobablecauseofthealarm.
severityistheperceivedseverityofthealarm.
timeistheUTCtimethealarmwasgenerated.
extraisanyextrainformationdescribingthealarm.
4 EventandAlarmhandlingApplication(EVA)
1.2: Services
Event
Whenaneventisgenerated,theeventrecordissenttoalarm handler. Ithasthefollowingattributes:
name
(cid:15)
sender
(cid:15)
time
(cid:15)
extra
(cid:15)
Thenameisthenameofthecorrespondingeventtype,definedineventTable.
senderisatermthatuniquelyidentifiestheresourcethatgeneratedtheevent.
timeistheUTCtimetheeventwasgenerated.
extraisanyextrainformationdescribingtheevent.
Example
Asanexampleofhowtoregisterandsendeventsandalarms,considerthefollowingcode:
%%%-----------------------------------------------------------------
%%% Resource code
%%%-----------------------------------------------------------------
reg() ->
eva:register_event(boardRemoved, true),
eva:register_event(boardInserted, false),
eva:register_alarm(boardFailure, true, equipment, minor).
remove_board(No) ->
eva:send_event(boardRemoved, {board, No}, []).
insert_board(No, BoardName, BoardType) ->
eva:send_event(boardInserted, {board, No}, {BoardName, BoardType}).
board_on_fire(No) ->
FaultId = eva:get_fault_id(),
%% Cause = fire, ExtraParams = []
eva:send_alarm(boardFailure, FaultId, {board, No}, fire, []),
FaultId.
Twoeventsandonealarmisdefined. Boardremovalisaneventthatisloggedbydefault,andboard
insertionisaneventthatisnotloggedbydefault. ThealarmequipmentFailureisaminoralarmthatis
loggedbydefault.
WhentheapplicationdetectsthatboardNisonfire,board on fire(N)iscalled. Thisfunctionis
responsibleforsendingthealarm. Itgetsanewfaultidentifierforthefault,andcalls
eva:send alarm/5,pointingoutthefaultyboard(N),andsuggeststhattheprobablecauseforthe
equipmenttroubleisfire.
Theboard on firefunctionreturnsthefaultidentifierforthenewalarm. Thisfaultidentifiercanbe
usedatalatertimeinacalltoeva:clear alarm(FaultId)toclearthealarm.
EventandAlarmhandlingApplication(EVA) 5
Chapter1: EVAUser’sGuide
1.2.2 Log Control Service
TheLogControlservicecontainsfunctionsformonitoringlogs,andfunctionsfortransferringlogsto
remotehosts,e.g. managementstations. ThemainpurposeoftheLogControlserviceistoprovideone
entitythroughwhichalllogsinthesystemcanbecontrolledbyamanagementstation. Regardlessof
thetypelog,alllogsarecontrolledinasimiliarfashion.
Clientscanregistertheirlogsinthelogserver. Managementapplicationscancontrolthelogs,and
transferthelogstoaremotehost.
LogMonitoring
Thisserviceusesalogserver thatmonitorsalllogsinthesystem. Eachlogusesthestandardmodule
disk logfortheactuallogging.
Eachloghasanadministrativeandanoperationalstatus,thatbothcanbeeitherupordown. Ifthe
operationalstatusisup,thelogisworking,andifitisdown,thelogdoesnotwork. Theadministrative
statusiswritable,andreflectsthedesiredoperationalstatus. Normallytheyareboththesame. Ifthe
administrativestatusissettoup,theoperationalstatuswillbeupaswell. However,ifthelogforsome
reasondoesnotwork,e.g. ifthediskpartitionisfull,theoperationalstatuswillbedown. Whenthe
operationalstatusisdown,noeventsareloggedinthelog.
Alarms TheTlogservicedefinestwoEVAalarms;log file errorandlog wrap too often.
log file error. Thisalarmisgeneratedifafileerroroccurswhenanitemislogged. Default
(cid:15) severityiscritical. ThecauseforthisalarmcanbeanyReasonasreturnedfromfile:writein
caseoferror. Thealarmisclearedifthefilesystemstartsworkingagain. Forexample,thealarm
canbegeneratedifthepartitionisfull,andclearedwhenspaceisavailable.
log wrap too often. Thisalarmisgeneratedwhenthelogwrapsmoreoftenthanthewraptime.
(cid:15) Defaultseverityismajor. Thecauseforthisalarmisundefined. Thealarmisclearedifthelog
wrapswithinthewraptime,thenexttimeitwraps.
Example ThefollowingisanexampleofcodethatcreatesalogtobecontrolledbythegenericLog
Controlfunction:
start() ->
disk_log:open([{name, "ex_log"},
{file, "ex_log/ex_log.LOG"},
{type, wrap},
{size, {10000, 4}}]),
log:open("ex_log", ex_log_type, 3600).
test() ->
%% Log an item
disk_log:log("ex_log", {1, "log this"}),
%% Set the administrative status of the log to ’down’
log:set_admin_status("ex_log", down),
%% Try to log - this one won’t be logged
disk_log:log("ex_log", {2, "won’t be logged"}),
Logs1 = log:get_logs(),
6 EventandAlarmhandlingApplication(EVA)