work manager

8/18/2019 Work Manager

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WebLogic Server 9/10 Administration L2

Work Manager

Prachi Joshi


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Objectives

At the end of this session, participant should be able to

Explain WebLogic thread pool Describe the concept of Work Manager

Use Work Managers to Optimize cheduled Work


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Contents

WebLogic er!er "hread #ools

$ntroduction to Work ManagersWork Manager %omponents

%onfiguring Work Manager

&e'uest %lasses

%onstraints

tuck "hread (andling

Work Manager cope Default Work Manager

)lobal Work Managers

Application*scoped Work Managers

Deplo+ment Descriptor Examples


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Thread oo! in O!der "ersions

#rocessing as performed in multiple execute 'ueues

Different classes of ork ere executed in different'ueues, based on priorit+ and ordering re'uirements, and

to a!oid deadlocks

$n addition to the default execute 'ueue,

eblogic-kernel-default, there ere pre*configured 'ueuesdedicated to internal administrati!e traffic, such as

eblogic-admin-(""# and eblogic-admin-&M$

"hread usage as controlled b+ Altering the number of threads in the default 'ueue

%onfiguring custom execute 'ueues to ensure that particular

applications had access to a fixed number of execute threads,

regardless of o!erall s+stem load


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WebLogic Server Thread oo!s

WebLogic er!er uses a single thread pool, in hich all

t+pes of ork are executed

Work is prioritized based on rules defined, and run*time

metrics, including Actual time it takes to execute a re'uest

&ate at hich re'uests are entering and lea!ing the pool

"he common thread pool changes its size automaticall+ to

maximize throughput

"he 'ueue monitors throughput o!er time and based on

histor+, determines hether to ad.ust the thread count

/or example

$f historical throughput statistics indicate that a higher

thread count increased throughput, WebLogic

increases the thread count


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WebLogic Server Thread oo!s Contin#ed$

"his strateg+ makes it easier for administrators to

Allocate processing resources Manage performance

$t a!oids effort and complexit+ in!ol!ed in %onfiguring

Monitoring

"uning

custom executes 'ueues


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%ntrod#ction to Work Managers

WebLogic er!er prioritizes ork and allocates threads

based on an execution model $t takes into account Administrator*defined parameters

Actual run*time performance and throughput

Administrators can configure a set of schedulingguidelines and associate them ith One or more applications

#articular application components

At run time, WebLogic er!er uses these guidelines to

assign pending ork and en'ueued re'uests to execution

threads


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Work Manager Com&onents

"o manage ork in applications, folloing Work Manager

components can be defined0

/air hare &e'uest %lass

&esponse "ime &e'uest %lass

Min "hreads %onstraintMax "hreads %onstraint

%apacit+ %onstraint

%ontext &e'uest %lass


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Con'ig#ring Work Manager

Work Manager can be configured at

Domain le!el Application le!el

Module le!el

$t can be configured in config-xml3 %an be assigned to an+ application, or application

component, in the domain

eblogic*application-xml3 %an be assigned to that application, or

an+ component of that application

eblogic*e.b*.ar-xml or eblogic-xml3 %an be assigned to that

component eblogic-xml3 Work Managers specified for a Web application

Or b+ using Administration %onsole


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Sam&!e Work Manager

4ork*manager5

4name5highpriorit+6orkmanager47name54fair*share*re'uest*class5

4name5high6priorit+47name5

4fair*share589947fair*share5

47fair*share*re'uest*class5

4min*threads*constraint5

4name5Min"hreads%ount/i!e47name5

4count5:47count5

47min*threads*constraint5

47ork*manager5


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(e'erencing Work Manager in Web A&&!ication

4init*param5

4param*name5l*dispatch*polic+47param*name54param*!alue5highpriorit+6orkmanager47param*!alue5

47init*param5


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(e)#est C!asses

A re'uest class expresses a scheduling guideline that

WebLogic er!er uses to allocate threads to re'uests

&e'uest classes help ensure that high priorit+ ork is

scheduled before less important ork, e!en if the high

priorit+ ork is submitted after the loer priorit+ ork

WebLogic er!er takes into account ho long it takes forre'uests to each module to complete

"here are multiple t+pes of re'uest classes, each of hich

expresses a scheduling guideline in different terms

A Mork Manager ma+ specif+ onl+ one re'uest class


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'air*share*re)#est*c!ass

pecifies the a!erage thread*use time re'uired to process

re'uests

/air share is a relati!e !alue and not actual percentage

/or example, "he Work Manager for ModuleA specifies a fair*share*re'uest*

class of ;9

"he Work Manager for Module< specifies a fair*share*re'uest*

class of =9

During a period of sufficient demand, ith a stead+ stream of

re'uests for each module such that the number re'uests exceed

the number of threads, WebLogic er!er ill allocate ;9> and=9> of the thread*usage time to ModuleA and Module


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Sam&!e

4ork*manager5

4name5highpriorit+6orkmanager47name54fair*share*re'uest*class5

4name5high6priorit+47name5

4fair*share589947fair*share5

47fair*share*re'uest*class5

47ork*manager5


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res&onse*time*re)#est*c!ass

pecifies a response time goal in milliseconds

&esponse time goals are not applied to indi!idualre'uests

WebLogic er!er computes a tolerable aiting time for

re'uests ith that class

$t is computed b+ subtracting the obser!ed a!eragethread use time from the response time goal

$t schedules re'uests so that the a!erage ait for

re'uests ith the class is proportional to its tolerable

aiting time


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res&onse*time*re)#est*c!ass Contin#ed$

/or example, ModuleA and Module< ha!e response time goals of =999 ms and

:999 ms, respecti!el+

actual thread use time for an indi!idual re'uest is less than its

response time goal

During a period of sufficient demand, ith a stead+ stream of

re'uests for each module such that the number of re'uestsexceed the number of threads, and no ?think time@ dela+s

beteen response and re'uest

WebLogic er!er ill schedule re'uests for ModuleA and

Module< to keep the a!erage response time in the ratio =3:

"he actual a!erage response times for ModuleA and Module<might be higher or loer than the response time goals, but ill be

a common fraction or multiple of the stated goal

$f the a!erage response time for ModuleA re'uests is 8,999 ms-,

the a!erage response time for Module< re'uests is =,:99 ms-


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Sam&!e

4ork*manager5

4name5responsetime6orkmanager47name54response*time*re'uest*class5

4name5m+6response6time47name5

4goal*ms5=99947goal*ms5

47response*time*re'uest*class5

47ork*manager5


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conte+t*re)#est*c!ass

Assigns re'uest classes to re'uests based on context

information, such as the current user or the current user1s

group

Lets +ou define re'uest classes in an application1s

deplo+ment descriptor based on a user1s context


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Sam&!e

4ork*manager5

4name5context6orkmanager47name54context*re'uest*class5

4name5test6context47name5

4context*case5

4user*name5s+stem47user*name54re'uest*class*name5high6fairshare

47re'uest*class*name5

47context*case5

4context*case54group*name5e!er+one47group*name5

4re'uest*class*name5lo6fairshare

0


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Constraints

A constraint defines minimum and maximum numbers of

threads allocated to execute re'uests

Also the total number of re'uests that can be 'ueued or

executing before WebLogic er!er begins re.ecting

re'uests

"+pes of constraints max*threads*constraint

min*threads*constraint

capacit+


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ma+*threads*constraint

Limits the number of concurrent threads executing

re'uests from the constrained ork set

Default is unlimited

$t can be defined in terms of a the a!ailabilit+ of the

resource that re'uests depend upon, such as a

connection pool

$t might pre!ent a re'uest class from taking its fair share

of threads or meeting its response time goal

Once the constraint is reached the ser!er does not

schedule re'uests of this t+pe until the number ofconcurrent executions falls belo the limit

"he ser!er then schedules ork based on the fair share

or response time goal


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min*threads*constraint

)uarantees the number of threads the ser!er ill allocate

to affected re'uests to a!oid deadlocks

Default is zero

A min*threads*constraint !alue of one is useful

/or example, for a replication update re'uest, hich is

called s+nchronousl+ from a peer A min*threads*constraint might not necessaril+ increase a

fair share

"his t+pe of constraint has an effect primaril+ hen the

ser!er instance is close to a deadlock condition $t ill cause WebLogic er!er to schedule a re'uest e!en

if re'uests in the ser!ice class ha!e gotten more than its

fair share recentl+


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ca&acit,

%auses the ser!er to re.ect re'uests onl+ hen it has

reached its capacit+

Default is *8

$ncludes all re'uests, 'ueued or executing, from the

constrained ork set

Work is re.ected either hen an indi!idual capacit+threshold is exceeded or if the global capacit+ is

exceeded

"his constraint is independent of the global 'ueue

threshold


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St#ck Thread -and!ing

$n response to stuck threads, a tuck "hread Work

Manager component can be defined

$t can shut don the Work Manager

Mo!e the application into admin mode

Mark the ser!er instance as failed


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.+am&!e

/olloing Work Manager shuts don the Work Manager

hen to threads are stuck for longer than 9 seconds

4ork*manager5

4name5stuckthread6orkmanager47name5

4ork*manager*shutdon*trigger54max*stuck*thread*time5947max*stuck*thread*time5

4stuck*thread*count5=47stuck*thread*count5

47ork*manager*shutdon*trigger5

47ork*manager5


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Work Manager Sco&e

"hree t+pes of Work Managers

%haracterized b+ its scope and ho it is defined and used

Default Work Manager

)lobal Work Managers



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e'a#!t Work Manager

(andle thread management and perform self*tuning

$t is used b+ an application hen no other Work Managersare specified in the application1s deplo+ment descriptors

Default Work Manager ma+ be sufficient for most

application re'uirements

Applications are gi!en e'ual priorit+ for threads and arepre!ented from monopolizing them

Default Work Manager can be o!erriden b+ creating and

configuring a global Work Manager called default

"his allos to control the default thread*handling beha!iorof WebLogic er!er


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When to se Work Managers

"he default fair share is not sufficient

A response time goal is re'uired

A minimum thread constraint needs to be specified to

a!oid ser!er deadlock


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!oba! Work Managers

)lobal Work Managers are a!ailable to all applications

and modules deplo+ed on a ser!er, in the WebLogic

Administration %onsole and in config-xml

An application uses a globall+*defined Work Manager as a

template

Each application creates its on instance hich handles

the ork associated ith that application and separates

that ork from other applications

"his separation is used to handle traffic directed to to

applications hich are using the same dispatch polic+

Although each application implements its on Work

Manager instance, the underl+ing components are shared


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Con'ig#ring !oba! Work Managers


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Con'ig#ring !oba! Work Managers Contin#ed$


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'i i ! b ! k i d


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A !i i d W k M


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A&&!ication*sco&ed Work Managers

Work Managers that are a!ailable onl+ to a specific

application or module

Application*scoped Work Managers can be defined in the

WebLogic Administration %onsole and in the folloing

descriptors3 eblogic*application-xml

eblogic*e.b*.ar-xml

eblogic-xml

$f +ou do not explicitl+ assign a Work Manager to an

application, it uses the default Work Manager

A method is assigned to a Work Manager, using the4dispatch*polic+5 element in the deplo+ment descriptor

C 'i i A !i i d W k M


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Con'ig#ring A&&!ication*sco&ed Work Managers

C 'i i A !i ti d W k M C ti d


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Con'ig#ring A&&!ication*sco&ed Work Managers Contin#ed$

C 'i i A !i ti d W k M C ti d


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Con'ig#ring A&&!ication*sco&ed Work Managers Contin#ed$

! t i t . !


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e&!o,ment escri&tor .+am&!es

eblogic*e.b*.ar-xml

eblogic*e.b*.ar-xml With %onnection #ool


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S#mmar,

$n this session, e co!ered

WebLogic er!er "hread #ools

$ntroduction to Work Managers

Work Manager %omponents

%onfiguring Work Manager

&e'uest %lasses%onstraints

tuck "hread (andling

Work Manager cope

Default Work Manager )lobal Work Managers


Deplo+ment Descriptor Examples


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