Skip to Content
avatar image
Former Member

Performance issue with a PI System

Hello

I am currently doing my Master Thesis, which is about a Software Experiment comparing performance between two "architectures" in SAP.

However, I am getting some unexplained pauses in the PI system, which I don't understand. I am not sure, whether this is a problem with the settings or a problem with the PI system itself (there might be a reason for the pauses), but the pauses are skewing the results and therefore the survey.

The scenario is this:

A number of XML files is placed on one system, and we want to extrapolate data from these files and insert the data in a database on another system.

The servers are all 3 GHz servers (4 cores), with 16 GB ram. The "file system" and the "database system" are both running SAP 6.0, while the PI system is running 7.0.

Architecture 1 - Two servers:

We use an ABAP program and a XSLT transformation to extrapolate and transfer data from the system with the files to the system with database. An experiment with 10.000 files took 191,879 seconds.

Architecture 2: - Three servers:

The same servers are used as in Architecture 1, however a PI System is used to extrapolate and transfer the data from the system with the files to the system with database. I am using a File Adapter. An experiment with 10.000 files took 728,53 seconds.

This is quite a bit longer and the reason for this can be found in the timestamps used to calculate the time. Each piece of data gets a timestamp from each server, an a example can be seen below:

...

...42.4440000

...42.4440000

...45.8040000

...45.8190000

...

As you can see there is about a 3 sec pause, and this pause occurs once every 20-30 files. Can you point at any obvious reasons for this small pause?

As I am learning PI is a complex system, so I am pretty sure you need more information about how the system was set up, unless the answer is simple. I am of course, more than willing to supply more information, so that I might get a correct evaluation of the performance of the PI system, however I am not sure what kind information you want. Because of the complexity of the system, a full description of the set up and the settings would transform this post into a novel.

Best Regards and thank you in advance!

Andreas

Add comment
10|10000 characters needed characters exceeded

  • Get RSS Feed

2 Answers

  • Best Answer
    avatar image
    Former Member
    Nov 12, 2009 at 04:55 PM

    Hi,

    Architecture 1 - Two servers:

    We use an ABAP program and a XSLT transformation to extrapolate and transfer data from the system with the files to the system with database. An experiment with 10.000 files took 191,879 seconds.

    Point-to-Point communication is always faster, but when we talk about complex IT architecture, then the idea is to streamline the flow of communication through a central hub. So, performance will definitely won't be the same.

    Architecture 2: - Three servers:

    The same servers are used as in Architecture 1, however a PI System is used to extrapolate and transfer the data from the system with the files to the system with database. I am using a File Adapter. An experiment with 10.000 files took 728,53 seconds.

    What is the polling interval of File Adapter? What is the size of each files? What is the PI hardware configuration? What mapping you are using? All these issues can affect / slower down the performance.

    Hope this helps.

    Regards,

    Neetesh

    Add comment
    10|10000 characters needed characters exceeded

    • Former Member

      Dear Neetesh

      Thank you for your answer!

      Point-to-Point communication is always faster, but when we talk about complex IT architecture, then the idea is to streamline the flow of communication through a central hub. So, performance will definitely won't be the same.

      This is true, I did not expect the PI system to perform nearly as good as the Point-to-Point system, I am more worried that the results is not representative, because of all the pauses.

      What is the polling interval of File Adapter? What is the size of each files? What is the PI hardware configuration? What mapping you are using? All these issues can affect / slower down the performance.

      What is the polling interval of File Adapter?

      When you say Polling Interval of the File Adapter, do you mean how often it checks for Files? Because that is the only option I can find:

      "Number of seconds that the adapter is to wait if no files are found for processing" (from SAP Guide)

      If so, this is set to 0. In order to start the test, I deactivate the File Adapter, copy the files and activate it again. It starts almost immediately with getting the files.

      What is the size of each files?

      The size of the files varies between 2KB and 128KB, depending of the amount of data. The processing time does go up, but not as much as you would expect. For example 10.000 files with the size of 2KB takes around 12 min and 10.000 files with the size of 128KB takes around 15 min. The problem is that in both cases, there is these 3 sec pauses.

      What is the PI hardware configuration?

      I am not sure what you mean. The server is a 3 GHz server (4 cores), with 16 GB ram.

      What mapping you are using?

      All data elements from the XML files are mapped directly to the IDOC. There is no processing (or call to any functions) or any changes made to the data, so the mapping is direct. Except I have made a custom function, which simply calls a timestamp function, in order to get the timing.

      On Tuesday (two days time from now), I get more servertime, I will try to see if I can find an actual Polling Interval of the File Adapter, if this is what you meant.

      Best,

      Andreas

  • Nov 13, 2009 at 07:27 AM

    Hi

    Along with reason mentioned in above post below mentioned reason can also affect performance.

    When you are processing multiple messages in XI then those messages will be passed in Queues.

    So unless first message get processed in the queue next message will not get processed. This may affect the performance.

    Add comment
    10|10000 characters needed characters exceeded

    • Former Member Former Member

      Dear S. Gökhan

      Thanks again for your help.

      You can the SOAP header below. It is perhaps not the best example, as the first queue does not show any particular delay, however the second one does.

      Sorry for the link, however I could not get this forum to show the data in human readable format.

      http://dl.dropbox.com/u/322194/soap_retursvar.xml

      I am sure it is not a hardware problem. I tried using the PI system as the file system in the point to point scenario, and there was no problem (no pauses) in this and the system functions well in all other aspects.

      However I was told today that time was running out (because sudden and external factors affecting the company at which I am doing my Thesis) and it is possible that I will not be able to get more server time, so I would hate for you to spend to much time on this, without knowing that I might not be able to try out any new solutions. Of course, if you can find any wrong settings in the trace, I would be extremely grateful, as it would either be part of my report, or if I can "sneak back in", be tested.

      Based on the previous we discussed, I have dedicated a section of my Thesis, that explains alternative strategies (Advanced Adapter and MSG packing), but that part will, for now, remain untested.

      Best,

      Andreas