Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

Hi!

 I have set NUMTCB=1 to limit the SPs to run "one at a time" due to DD card dependancies and I have vague memories of JAVA SPs that swallowed memory like it was going out of fashion, so I would guess it was those JAVA babies "back in the day" - Apart from limiting parallel running I can see no reason.

Hope that helps!

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

Hi!

 I have set NUMTCB=1 to limit the SPs to run "one at a time" due to DD card dependancies and I have vague memories of JAVA SPs that swallowed memory like it was going out of fashion, so I would guess it was those JAVA babies "back in the day" - Apart from limiting parallel running I can see no reason.

Hope that helps!

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

I have always had NUMTCB=30 for our WLM address spaces that run Cobol and C, haven't experienced any problems.

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

Vague memories of DB2 V6 with 2GB address spaces.   When were the SPs that use the environments created?

Perhaps no longer relevant.

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

Good morning James, 

they were created on 2011, long ago :-)

I have found others with the MNSPAS parameter, that according to IBM:

"If the environment is one in which the cost of starting new address spaces is very high, set the MNSPAS subsystem parameter to specify the minimum number of address spaces that are to be started and maintained."

This MNSPAS was also added on 2011, and its remark refers the apar PM27097, I don't know if still starting a new address spaces is that costly.

Thank you very much!

Vague memories of DB2 V6 with 2GB address spaces.   When were the SPs that use the environments created?

Perhaps no longer relevant.

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------

The cost of starting a new address space isn't really about the system resources it takes. It's really more about can the application(s) calling the SPs afford to wait for a new address space to start. 

With WLM cycling every 10 seconds, before it decides to start another WLM SP task, that 10 seconds could be costly to you.

I've experienced slowdowns in applications and I could not afford to wait for WLM to react, so I use NUMTCB for certain address spaces to avoid this cost.

Good morning James, 

they were created on 2011, long ago :-)

I have found others with the MNSPAS parameter, that according to IBM:

"If the environment is one in which the cost of starting new address spaces is very high, set the MNSPAS subsystem parameter to specify the minimum number of address spaces that are to be started and maintained."

This MNSPAS was also added on 2011, and its remark refers the apar PM27097, I don't know if still starting a new address spaces is that costly.

Thank you very much!

Vague memories of DB2 V6 with 2GB address spaces.   When were the SPs that use the environments created?

Perhaps no longer relevant.

Good day, 

while reviewing the WLM environments at one system, I found one that is running with NUMTCB=5, it has an old remark saying that the WLM is for High Storage SP.

I checked the SP assigned to it, and all of them have some LOB column, but there are others with LOB columns running at WLM environments with higher NUMTCB.

At IBM site I can see that the recommended range is from 10 to 40 NUMTCB for SP written in  Cobol and C, and one of the ways to increase the perfomance of the Stored Procedures is increasing the NUMTCB,

So, does make any sense to have a WLM with NUMTCB=5? Can this be an old configuration? Is there anybody who had to set the NUMTCB to something lower than 10 due to storage or any other problem?

Thank you!

#Db2, #Db2 for z/OS 

------------------------------
Soledad Martinez
Db2 z/OS System Programmer
Volkswagen Group Services
Salinas - Asturias
------------------------------