DB2 - Memory for Mips - MDUG 2013May15

8/12/2019 DB2 - Memory for Mips - MDUG 2013May15

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2013 IBM Corporation

Information Management

Memory for MIPS: Leveraging Big Memory onSystem z to Enhane !B2 CP" Effiieny

Mihigan !B2 "sers #ro$p

May 1%& 2012

'o(ert Cattera))& IBM

rfatter*$s+i(m+om


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2013 IBM Corporation2


,gen-a

.he $rrent )an-sape

#etting yo$r ($ffer poo) ho$se in or-er

Being (o)- / ($t not re)ess / in asing for more rea)

storage for a !B2 s$(systeme opport$nities for ep)oiting 'ELE,SE4!E,LL5C,.E6

5ther ays to tra-e memory for MIPS


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.he $rrent )an-sape


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System z server memory: getting BI#

Pro-$tion z85S LP,'s ith rea) storage reso$res of 20#B& 70 #B& or more are inreasing)y ommon

/Seeing some pro-$tion z85S LP,'s ith 1009 #B of rea) storage

hat;s -riving the tren- toar-s )arger z85S LP,' memory

sizes onfig$rations

? Proessing apaity 4(ase- on n$m(er an- spee- of engines in z85S

images6 eeps groing

? zEC12 server: $p to 101 engines& eah paing a(o$t 1000 MIPS of

apaity

? ot $n$s$a) to see 10@20 #B of rea) storage per engine

/'e-$e- ost of System z memory

AA


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2013 IBM Corporation%


e ays to )everage Big Memory on z

'eent !B2 for z85S -eve)opments provi-e more opport$nitiesto $se System z memory a-vantageo$s)y

, fe eamp)es 4overe- in more -etai) )ater in presentation6:

/Page@fie- ($ffer poo)s 4an-& ith !B2 10& $se of 1 MB page frames for

s$h poo)s6

/!B2@aare =pinning> of o(ets in ($ffer poo)s 4!B2 106

/.hrea-@re)ate- virt$a) storage a)most entire)y a(ove 2 #B =(ar> ith !B2

10 4hen paages (o$n- or re(o$n- in !B2 10 environment6

? More on$rrent threa-s per s$(system

? More =hea- room> for $se of 'ELE,SE4!E,LL5C,.E6 (in- option

/igh@performane !B,.s 4!B2 106 / tie- to 'ELE,SE4!E,LL5C,.E6


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2013 IBM CorporationD


.here are a )ot of =s)eeping giga(ytes> o$t there

,t many !B2 for z85S sites& L5.S of spare memory apaity!o yo$ no yo$r z85S system;s -eman- paging rate that I )ie to $se is the-eman- paging rate

/,s yo$ imp)ement memory@for@MIPS hanges& eep an eye on the z85S

LP,';s -eman- paging rate& an- -on;t )et this get o$t of han-

/If the -eman- paging rate is in the sing)e -igits 4or )ess6 per seon-& it;s

not o$t of han-

hatever yo$r LP,';s -eman- paging rate& I;- (e aref$)

a(o$t $sing more than %0 of an LP,';s memory for !B2

($ffer poo)s

/I;ve seen LM size a ($ffer poo) onfig$ration at 30@70 of LP,'

memory 4,L.E' B"HHE'P55L4BPn6 ,".5SIQE4JES66


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eep monitoring rea- I85 rate for ($ffer poo)s

I genera))y tae a triage approah: fo$s efforts on the poo)s

ith the highest rea- I85 rates

/ighest rate I;ve seen is A000 rea- I85s per seon- for one ($ffer poo)

My aim: if possi()e& get rea- I85 rate to )ess than 1000 per

seon- for eah ($ffer poo)/If that o(etive is aomp)ishe- 4or if I;m seeing -iminishing ret$rnsith respet to en)arging a high@I85 ($ffer poo)6& I t$rn my fo$s to

poo)s ith rea- I85 rates (eteen 100 an- 1000 per seon-

? ie to get these (e)o 100 per seon-& if possi()e

eep in min-: it;s not $st a(o$t maing eisting poo)s )arger

/,t some point& yo$ may ant to reate a ne BPy& an- reassign

o(ets to that poo) from BP

? Can (e parti$)ar)y effetive for separating =history> vs+ =$rrent> ta()es&

aess patterns for hih ten- to (e -ifferent


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If -ata sharing& -on;t forget gro$p ($ffer poo)s

Sometimes peop)e i)) mae BP )arger aross mem(ers of a-ata sharing gro$p& an- i)) forget to en)arge #BP

aor-ing)y

/If aggregate size of )oa) BPs gets too )arge re)ative to the size of the

orrespon-ing #BP& yo$ o$)- en- $p ith a )ot of -iretory entry

re)aims an- that;s not goo- for performane

? Can he on -iretory entry re)aim ativity $sing o$tp$t of !B2 omman-

@!ISPL,J #'5"PB"HHE'P55L4#BPn6 #!E.,IL

Hor a 7 #BP ith the -efa$)t %:1 ratio of -iretory entries to

-ata pages& -iretory entry re)aims )ie)y to (e 0 if size of#BP is 70 of om(ine- size of assoiate- )oa) BPs

/Eamp)e: 3@ay gro$p& BP1 at 70 ($ffers 41D0 MB6 on eah mem(er

? #oo- #BP1 size is 70 43 1D0 MB6 O 1A2 MB


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2013 IBM Corporation2%


e opport$nities for ep)oiting'ELE,SE4!E,LL5C,.E6


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2013 IBM Corporation2D


hat;s goo- a(o$t 'ELE,SE4!E,LL5C,.E6 in !BM1

/.a)ing a(o$t the part of the E!M poo) $se- for C. 4i+e+& $rsor ta()e& if!B'M (o$n- -iret)y into p)an6 an- P. 4paage ta()e6

? Copies of paage an- $rsor ta()e setions a))oate- to threa-s

/!B2 monitor might refer to this part of E!M poo) as =Pages in '!S Poo)>

4a(ove an- (e)o the (ar6& in E!M poo) setion of statistis report

/"se of 'ELE,SE4!E,LL5C,.E6 maes more of this spae non@

stea)a()e& hih o$)- potentia))y )ea- to program fai)$re -$e to )a of

spae in E!M poo)

? #enera) reommen-ation: perentage of free pages in this part of the E!M

sho$)- (e at )east 10


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2013 IBM Corporation2F


!B2 10 threa- storage

%@A0 )ess $sage of (e)o@

the@(ar !BM1 virt$a) storage

ith !B2 10 vs+ !B2 A

/Primari)y -$e to movement of

a)most a)) threa-@re)ate- storage

a(ove the 2 #B (ar

'es$)t: m$h more virt$a)

storage =hea- room> for $se of

'ELE,SE4!E,LL5C,.E6

,)so& QP,'M no )onger )imits

spae avai)a()e for paage

ta()e / no pretty m$h )imite-

(y avai)a(i)ity of rea) storage

SC.

SP.

#)o(a) !SC

!B! C.8P.

Loa) !SC

.hrea- 8 Sta

%@A0 )ess $sage

!BM1 (e)o (ar

after 'EBI!

.hrea- 8 Sta8 oring


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2013 IBM Corporation2A


More on !B2 10 an- 'ELE,SE4!E,LL5C,.E6

Prior re)eases: 'ELE,SE4!E,LL5C,.E6 not honore- hen

paage ee$te- via !B,. 4i+e+& a !!H threa-6

/Instea-& treate- as tho$gh (o$n- ith 'ELE,SE4C5MMI.6

/hy: !B,.s an sti aro$n- a L5# time& an- there as onern that

om(ination of 'ELE,SE4!E,LL5C,.E6 an- !B,.s o$)- ()o

$ti)ities& !!L& (in-s& et+

!B2 10: hen paage (o$n- ith 'ELE,SE4!E,LL5C,.E6

is ee$te- via a =reg$)ar> !B,.& that !B,. (eomes a high@

performane !B,.

/'ELE,SE4!E,LL5C,.E6 honore-

/igh@performane !B,. -e-iate- to onnetion thro$gh hih it as

instantiate-& vs+ going (a into !!H threa- poo) hen transation en-s

/If threa- re$se- for same paage& yo$ get CP" (enefit of

'ELE,SE4!E,LL5C,.E6


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More on high@performane !B,.s

igh@performane !B,. i)) (e terminate- after (eing $se-to proess 200 $nits of or 4to free $p reso$res6

Can s$spen- honoring of 'ELE,SE4!E,LL5C,.E6 for

paages ee$te- via !B2 (y iss$ing omman- @M5!IHJ

!!H P#'EL4C5MMI.6/Iss$e @M5!IHJ !!H P#'EL4B!5P.6 to sith (a

hat if most of yo$r SL ee$te- thro$gh !!H is -ynami

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DB2 - Memory for Mips - MDUG 2013May15