Dispatching Priority of Db2 Monitors

Tekin Yavuz (Garanti Teknoloji)

Dispatching Priority of Db2 Monitors
Dispatching Priority of Db2 Monitors

Hi all,
How or in what way    lower dispatching priority of db2 montiors than dbm1 or mstr affects db2 threads?

Regards,Tekin...




+......................................................................................................................................+
"Bu mesaj ve ekleri mesajda gonderildigi belirtilen kisi ya da kisilere ozeldir ve gizlidir.
Bu mesajin muhatabi, ilgilisi, ya da gonderileni olmamaniza ragmen mesajin herhangi bir
sekilde tarafiniza ulasmis olmasi halinde anilan mesaj ve mesajda yer alan bilgilerin
gizliligi ve bu gizlilik yukumlulugune uyulmasi zorunlulugu tarafiniz icin de soz konusudur.
Bu yukumlulukle birlikte bu mesaji ve eklerini kullanamaz, kopyalayamaz baska kisilere
gonderemez ve aciklayamazsiniz. Boyle bir durumda lutfen mesaji gonderen kisiyi
bilgilendiriniz ve soz konusu mesaj ile eklerini bilgisayarinizdan ve sisteminizden derhal
siliniz. Bu mesaj ve eklerinde yer alan bilgi ve belgelerin dogru ve guncel olup
olmamasindan dolayi mesaji gonderen kisinin ya da sirketimizin herhangi bir sorumlulugu
bulunmamaktadir.E-posta mesajlari internet ortamininda degisime ugrayabilir. sirketimiz bu
mesajin ve icerdigi bilgilerin size degisiklige ugrayarak veya gec ulasmasindan,butunlugunun
ve gizliliginin korunamamasindan, virus icermesinden ve herhangi bir sebeple bilgisayariniza
ve sisteminize verebilecegi zararlardan sorumlu tutulamaz."
+......................................................................................................................................+

Tekin Yavuz (Garanti Teknoloji)

Dispatching Priority of Db2 Monitors
(in response to Tekin Yavuz (Garanti Teknoloji))
Dispatching Priority of Db2 Monitors

Hi again,

Do you have any opinion about this topic.Any comment would be appreciated.

Regards..


 -----Original Message-----
From:   Tekin Yavuz (Garanti Teknoloji) 
Sent:   Friday, December 27, 2002 7:06 PM
To:     [login to unmask email]
Subject:        Dispatching Priority of Db2 Monitors

Hi all,
How or in what way    lower dispatching priority of db2 montiors than dbm1 or mstr affects db2 threads?

Regards,Tekin...




+......................................................................................................................................+
"Bu mesaj ve ekleri mesajda gonderildigi belirtilen kisi ya da kisilere ozeldir ve gizlidir.
Bu mesajin muhatabi, ilgilisi, ya da gonderileni olmamaniza ragmen mesajin herhangi bir
sekilde tarafiniza ulasmis olmasi halinde anilan mesaj ve mesajda yer alan bilgilerin
gizliligi ve bu gizlilik yukumlulugune uyulmasi zorunlulugu tarafiniz icin de soz konusudur.
Bu yukumlulukle birlikte bu mesaji ve eklerini kullanamaz, kopyalayamaz baska kisilere
gonderemez ve aciklayamazsiniz. Boyle bir durumda lutfen mesaji gonderen kisiyi
bilgilendiriniz ve soz konusu mesaj ile eklerini bilgisayarinizdan ve sisteminizden derhal
siliniz. Bu mesaj ve eklerinde yer alan bilgi ve belgelerin dogru ve guncel olup
olmamasindan dolayi mesaji gonderen kisinin ya da sirketimizin herhangi bir sorumlulugu
bulunmamaktadir.E-posta mesajlari internet ortamininda degisime ugrayabilir. sirketimiz bu
mesajin ve icerdigi bilgilerin size degisiklige ugrayarak veya gec ulasmasindan,butunlugunun
ve gizliliginin korunamamasindan, virus icermesinden ve herhangi bir sebeple bilgisayariniza
ve sisteminize verebilecegi zararlardan sorumlu tutulamaz."
+......................................................................................................................................+

James Campbell

Re: Dispatching Priority of Db2 Monitors
(in response to Tekin Yavuz (Garanti Teknoloji))
I would suggest that if your monitor runs at a lower priority than a
DB2 address space, events can happen within DB2 which your monitor
will never see.

James Campbell

On 30 Dec 2002 at 11:32, Tekin Yavuz (Garanti Teknoloj wrote:

> Hi again,
> Do you have any opinion about this topic.Any comment would be
> appreciated.
> Regards..
>
> -----Original Message-----
> From: Tekin Yavuz (Garanti Teknoloji)
> Sent: Friday, December 27, 2002 7:06 PM
> To: [login to unmask email]
> Subject: Dispatching Priority of Db2 Monitors
> Hi all,
> How or in what way lower dispatching priority of db2 montiors than
> dbm1 or mstr affects db2 threads?
> Regards,Tekin...
>
>
>
> +.....................................................................
> .................................................................+
> "Bu mesaj ve ekleri mesajda gonderildigi belirtilen kisi ya da
> kisilere ozeldir ve gizlidir.
> Bu mesajin muhatabi, ilgilisi, ya da gonderileni olmamaniza ragmen
> mesajin herhangi bir
> sekilde tarafiniza ulasmis olmasi halinde anilan mesaj ve mesajda yer
> alan bilgilerin
> gizliligi ve bu gizlilik yukumlulugune uyulmasi zorunlulugu tarafiniz
> icin de soz konusudur.
> Bu yukumlulukle birlikte bu mesaji ve eklerini kullanamaz,
> kopyalayamaz baska kisilere
> gonderemez ve aciklayamazsiniz. Boyle bir durumda lutfen mesaji
> gonderen kisiyi
> bilgilendiriniz ve soz konusu mesaj ile eklerini bilgisayarinizdan ve
> sisteminizden derhal
> siliniz. Bu mesaj ve eklerinde yer alan bilgi ve belgelerin dogru ve
> guncel olup
> olmamasindan dolayi mesaji gonderen kisinin ya da sirketimizin
> herhangi bir sorumlulugu
> bulunmamaktadir.E-posta mesajlari internet ortamininda degisime
> ugrayabilir. sirketimiz bu
> mesajin ve icerdigi bilgilerin size degisiklige ugrayarak veya gec
> ulasmasindan,butunlugunun
> ve gizliliginin korunamamasindan, virus icermesinden ve herhangi bir
> sebeple bilgisayariniza
> ve sisteminize verebilecegi zararlardan sorumlu tutulamaz."
> +.....................................................................
> .................................................................+
>
> visit the DB2-L webpage at http://listserv.ylassoc.com. The owners of
> the list can



Tekin Yavuz (Garanti Teknoloji)

Re: Dispatching Priority of Db2 Monitors
(in response to James Campbell)
RE: Re: Dispatching Priority of Db2 Monitors

Hi James,
Is it also true for low CPU usage in the system.
For example when we are using Detector with SQL exception collection  on accidentally detector's dispatching priority was lower than dbm1  ,our db2 batch jobs began to have an unknown delay on a mvs nucleus load module(IGVGPVT) while the system CPU is aroun 40 % or 50 % .And those batch jobs runs three times slower thna normal running time.

I could not explain that unknown delay in our db2 batch jobs.How can lower dispatching priority causes batch jobs to run three times slower.

Thanks...
Tekin

-----Original Message-----
From: James Campbell [mailto:[login to unmask email]]
Sent: Tuesday, December 31, 2002 11:36 AM
To: [login to unmask email]
Subject: Re: Dispatching Priority of Db2 Monitors


I would suggest that if your monitor runs at a lower priority than a
DB2 address space, events can happen within DB2 which your monitor
will never see.

James Campbell

On 30 Dec 2002 at 11:32, Tekin Yavuz (Garanti Teknoloj wrote:

> Hi again,
> Do you have any opinion about this topic.Any comment would be
> appreciated.
> Regards..
>
>     -----Original Message-----
>     From:  Tekin Yavuz (Garanti Teknoloji)
>     Sent: Friday, December 27, 2002 7:06 PM
>     To: [login to unmask email]
>     Subject: Dispatching Priority of Db2 Monitors
>     Hi all,
>     How or in what way lower dispatching priority of db2 montiors than
>     dbm1 or mstr affects db2 threads?
>     Regards,Tekin...
>
>
>
> +.....................................................................
> .................................................................+
> "Bu mesaj ve ekleri mesajda gonderildigi belirtilen kisi ya da
> kisilere ozeldir ve gizlidir.
> Bu mesajin muhatabi, ilgilisi, ya da gonderileni olmamaniza ragmen
> mesajin herhangi bir
> sekilde tarafiniza ulasmis olmasi halinde anilan mesaj ve mesajda yer
> alan bilgilerin
> gizliligi ve bu gizlilik yukumlulugune uyulmasi zorunlulugu tarafiniz
> icin de soz konusudur.
> Bu yukumlulukle birlikte bu mesaji ve eklerini kullanamaz,
> kopyalayamaz baska kisilere
> gonderemez ve aciklayamazsiniz. Boyle bir durumda lutfen mesaji
> gonderen kisiyi
> bilgilendiriniz ve soz konusu mesaj ile eklerini bilgisayarinizdan ve
> sisteminizden derhal
> siliniz. Bu mesaj ve eklerinde yer alan bilgi ve belgelerin dogru ve
> guncel olup
> olmamasindan dolayi mesaji gonderen kisinin ya da sirketimizin
> herhangi bir sorumlulugu
> bulunmamaktadir.E-posta mesajlari internet ortamininda degisime
> ugrayabilir. sirketimiz bu
> mesajin ve icerdigi bilgilerin size degisiklige ugrayarak veya gec
> ulasmasindan,butunlugunun
> ve gizliliginin korunamamasindan, virus icermesinden ve herhangi bir
> sebeple bilgisayariniza
> ve sisteminize verebilecegi zararlardan sorumlu tutulamaz."
> +.....................................................................
> .................................................................+
>
> visit the DB2-L webpage at http://listserv.ylassoc.com. The owners of
> the list can


DB2-L webpage at http://listserv.ylassoc.com. The owners of the list can

+......................................................................................................................................+
“Bu mesaj ve ekleri mesajda gonderildigi belirtilen kisi ya da kisilere ozeldir ve gizlidir.
Bu mesajin muhatabi,   ilgilisi, ya da gonderileni olmamaniza ragmen mesajin herhangi bir
sekilde tarafiniza ulasmis olmasi halinde  anilan mesaj ve mesajda yer alan bilgilerin
gizliligi ve bu gizlilik yukumlulugune uyulmasi zorunlulugu tarafiniz icin de soz konusudur.
Bu yukumlulukle birlikte bu mesaji ve eklerini kullanamaz, kopyalayamaz  baska kisilere
gonderemez ve aciklayamazsiniz. Boyle bir durumda lutfen mesaji gonderen kisiyi 
bilgilendiriniz ve soz konusu mesaj ile eklerini bilgisayarinizdan ve sisteminizden derhal
siliniz. Bu mesaj ve  eklerinde yer alan bilgi ve belgelerin dogru ve guncel olup
olmamasindan dolayi mesaji gonderen kisinin ya  da sirketimizin herhangi bir sorumlulugu
bulunmamaktadir.E-posta mesajlari internet ortamininda degisime  ugrayabilir. sirketimiz bu
mesajin ve icerdigi bilgilerin size degisiklige ugrayarak veya gec ulasmasindan,butunlugunun
ve gizliliginin korunamamasindan, virus icermesinden ve herhangi bir sebeple bilgisayariniza
ve sisteminize verebilecegi zararlardan sorumlu tutulamaz.”
+......................................................................................................................................+

Phil Grainger

Re: Dispatching Priority of Db2 Monitors
(in response to Tekin Yavuz (Garanti Teknoloji))
Tekin (and everyone)

I had a brief chat with our Detector folks, and their comments follow (which
I think echos what most people consider as "best practice" for monitors, but
does stress the unfortunate events that can happen if you do NOT run your
monitor AT LEAST at the same priority as DB2):


In general, a monitor such as Detector, becomes a factor in the performance
of the address spaces being monitored. Therefore it is imperative that it
be run at a higher (or equal) dispatching priority than the tasks being
monitored, otherwise the monitored task will be waiting for the monitor to
be dispatched. This is especially important when collections are active for
online applications. The following is the text from the Detector User
Guide.

The MVS dispatching priority assigned to the Xmanager address space may be
of concern when Detector collection is active. Selected Detector collection
components executing within the Xmanager address space require CPU cycles to
be obtained at a comparable level to the application workload being
generated. <?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" />

We recommend that you assign Manager a dispatching priority equal to or
higher than the dispatching priority of the DB2 system services or database
services address spaces. If your installation has address spaces that use
DB2 and are assigned dispatching priorities higher than DB2, then the
dispatching priority assigned to Xmanager should be equal to or higher than
their dispatching priority.




Phil Grainger
Computer Associates
Product Manager, DB2
Tel: +44 (0)161 928 9334
Fax: +44 (0)161 941 3775
Mobile: +44 (0)7970 125 752
[login to unmask email]

-----Original Message-----
From: Tekin Yavuz (Garanti Teknoloji) [mailto:[login to unmask email]
Sent: 31 December 2002 10:20
To: [login to unmask email]
Subject: Re: [DB2-L] Dispatching Priority of Db2 Monitors



Hi James,
Is it also true for low CPU usage in the system.
For example when we are using Detector with SQL exception collection on
accidentally detector's dispatching priority was lower than dbm1 ,our db2
batch jobs began to have an unknown delay on a mvs nucleus load
module(IGVGPVT) while the system CPU is aroun 40 % or 50 % .And those batch
jobs runs three times slower thna normal running time.

Martin Packer

Re: Dispatching Priority of Db2 Monitors
(in response to Phil Grainger)
Phil, thank goodness you said that! I was going to respond to the original
comment that a monitor at a lower priority than a monitored address space
could miss events. That could happen regardless of the "priority"
hierarchy. Being higher "priority" won't GUARANTEE that doesn't happen.

Priority in quotations because in practice we're usually talking WLM and
for that DP is not really under our control, most of the time.

Regards, Martin

Martin Packer, MBCS Martin Packer/UK/IBM
020-8832-5167 in the UK (+44) (MOBX 273643, Internal 7-325167, Mobile
07802-245584)



"Grainger, Phil"
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Tekin (and everyone)

I had a brief chat with our Detector folks, and their comments follow
(which I think echos what most people consider as "best practice" for
monitors, but does stress the unfortunate events that can happen if you do
NOT run your monitor AT LEAST at the same priority as DB2):


In general, a monitor such as Detector, becomes a factor in the performance
of the address spaces being monitored. Therefore it is imperative that it
be run at a higher (or equal) dispatching priority than the tasks being
monitored, otherwise the monitored task will be waiting for the monitor to
be dispatched. This is especially important when collections are active
for online applications. The following is the text from the Detector User
Guide.

The MVS dispatching priority assigned to the Xmanager address space may be
of concern when Detector collection is active. Selected Detector collection
components executing within the Xmanager address space require CPU cycles
to be obtained at a comparable level to the application workload being
generated. <?xml:namespace prefix = o ns
= "urn:schemas-microsoft-com:office:office" />
We recommend that you assign Manager a dispatching priority equal to or
higher than the dispatching priority of the DB2 system services or database
services address spaces. If your installation has address spaces that use
DB2 and are assigned dispatching priorities higher than DB2, then the
dispatching priority assigned to Xmanager should be equal to or higher than
their dispatching priority.






Phil Grainger
Computer Associates
Product Manager, DB2
Tel: +44 (0)161 928 9334
Fax: +44 (0)161 941 3775
Mobile: +44 (0)7970 125 752
[login to unmask email]


-----Original Message-----
From: Tekin Yavuz (Garanti Teknoloji) [mailto:[login to unmask email]
Sent: 31 December 2002 10:20
To: [login to unmask email]
Subject: Re: [DB2-L] Dispatching Priority of Db2 Monitors



Hi James,
Is it also true for low CPU usage in the system.
For example when we are using Detector with SQL exception collection
on accidentally detector's dispatching priority was lower than dbm1
,our db2 batch jobs began to have an unknown delay on a mvs nucleus
load module(IGVGPVT) while the system CPU is aroun 40 % or 50 % .And
those batch jobs runs three times slower thna normal running time.