Exploiting Hardware Compression on the zEDC

[Ed_Arnold]

Before you do anything else, read and heed the following Technote:

APAR PI41677 zEDC support as updated by PI49323

http://www-01.ibm.com/support/docview.wss?uid=swg27046215


Now, how can you tell whether you have the hardware set up properly?

1. use the d iqp operator command to see if the feature is enabled:

D IQP                                       
IQP066I 09.59.54 DISPLAY IQP 613           
zEDC Information                           
 MAXSEGMENTS:                 4  (64M)     
 Previous MAXSEGMENTS:      N/A             
 Allocated segments:          4  (64M)     
 Used segments:               0  (0M)       
 DEFMINREQSIZE:               4K           
 INFMINREQSIZE:              16K           
 Feature Enablement:    Enabled


2. To see what state the zEDC is in, a D PCIE operator command displays the devices.  The zEDC is one of the 'Hardware Accelerator' entries

D PCIE                                                                   
IQP022I 10.10.58 DISPLAY PCIE 615                                       
PCIE     0011 ACTIVE                                                     
PFID      DEVICE TYPE NAME         STATUS  ASID  JOBNAME  CHID  VFN     
000000F6  Hardware Accelerator     ALLC    0012  FPGHWAM  0150  0006

3. The D PCIE,PFID=xx will display the details telling you the type of accelerator:

D PCIE,PFID=F6                                                           
IQP024I 10.12.38 DISPLAY PCIE 617                                       
PCIE     0011 ACTIVE                                                     
PFID      DEVICE TYPE NAME         STATUS  ASID  JOBNAME  CHID  VFN     
000000F6  Hardware Accelerator     ALLC    0012  FPGHWAM  0150  0006     
 CLIENT ASIDS: NONE                                                     
 Application Description: zEDC Express                                   
 Device State: Ready                                                     
 Adapter Info - Relid: 00000B  Arch Level: 03                           
                Build Date: 02/13/2014  Build Count: 03                 
 Application Info - Relid: 000000  Arch Level: 02

Note: 

Device State: Ready  is good
Device State: Intervention required is not good
any other state is transient, reissue the command


Of particular importance in the Technote is:

Two new compression types have been added to Content Manager OnDemand, named OD77HW and OD77LiteHW. In order to leverage hardware-based compression, you must define the document and resource compression types to one of these values.

Ed

[Justin Derrick]

I understand a similar device is also available for AIX.  Given that we don't pay for MIPS on AIX, it seems less enticing.

Do you have any 'before' and 'after' benchmarks?

[Ed_Arnold]

Do you have any 'before' and 'after' benchmarks?

Sadly, I don't have access to a zEDC processor at the moment.

However, I asked someone who does to run a small benchmark for me using the Unix Systems Services time command:

time runs the command given as its argument and produces a breakdown of 
total time to run (real),
total time spent in the user program (user), and
total time spent in system processor overhead (sys).                      

Here's the JCL for the benchmark:

//TMP1  EXEC  PGM=IKJEFT01,                                         
//            DYNAMNBR=200,REGION=0M                               
//SYSPROC  DD  DSN=SYS1.SBPXEXEC,DISP=SHR                           
//*                                                                 
//SYSTSPRT DD  SYSOUT=*                                             
//*                                                                 
//SYSTSIN  DD  *                                                   
 oshell time /usr/lpp/ars/V9R5M0/bin/arsadmin compress -c 'H' -s + 
    /usr/lpp/ars/V9R5M04/locale/icudt53e.dat -o /dev/null           
 oshell time /usr/lpp/ars/V9R5M0/bin/arsadmin compress -c 'O' -s + 
    /usr/lpp/ars/V9R5M04/locale/icudt53e.dat -o /dev/null           
/*                                                                 


-c H for hardware compression

-c O for OD77

Note:  we used file icudt53e.dat just because it's big.   

The output:


  oshell time /usr/lpp/ars/V9R5M04/bin/arsadmin compress -c 'H' -s /usr/lpp/ars/V9R5M04/locale/icudt53e.dat -o /dev/null
 READY
  oshell time /usr/lpp/ars/V9R5M04/bin/arsadmin compress -c 'O' -s /usr/lpp/ars/V9R5M04/locale/icudt53e.dat -o /dev/null
 READY
 END

 real   0m 2.64s
 user   0m 0.04s
 sys    0m 0.01s

 real   0m 5.21s
 user   0m 1.01s
 sys    0m 0.33s

As always, what you get out of compression highly depends on what you put in.

Ed

       

[Justin Derrick]

I can really only see this being a big advantage at the very largest of CMOD shops.

I'll check into this and see if it's possible to get access to a demo unit to play with.

[Ed_Arnold]

http://www.ibm.com/support/knowledgecenter/SSLTBW_2.2.0/com.ibm.zos.v2r2.ieag200/smf30-zedc.htm?lang=en

Ed

[Justin Derrick]

Your link didn't work for me -- it appears the 'pipe' character in front of it is breaking it somehow.  Can you edit to fix?  Thx.

[Ed_Arnold]

Your link didn't work for me -- it appears the 'pipe' character in front of it is breaking it somehow.  Can you edit to fix?  Thx.

Done!  I've learned something new.

Ed

[Ed_Arnold]

At last, published numbers:

From:

https://www.youtube.com/watch?v=edDx2L71yR0

At the 34:42 mark, IBM Content Manager OnDemand V9.5[0.3]

"MIPs reduction up to 75% compared to existing software based compression."

If you use APA - Application Performance Analyzer or STROBE you can measure the time in compression/decompression.

Ed