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Author's profile photo Juan Reyes

Basic start-up troubleshooting – the logical sequence!

If I had to select one single issue that people report more than anything else in the  Basis discussion forums it has to be problems they have starting an ABAP system.

Over the years I have read hundreds of discussions and for some reason the majority of posts start with a brief explanation of the problem and a “copy” of the dispatcher developer trace. Why?, There’s really not enough information there for anyone without a crystal ball!

If you find yourself in this situation, What do you do?

Basically when you start the system…

Database starts

SAP checks if the database is available and if it is not it starts the database. No dedicated developer trace is created in the work directory as the database has its own logs.  If the database does not start correctly it should be visible within seconds.

Message server kicks in

The message server is the first part of the system to start, it handles the communications between the instances.  Only one message server is available per system, regardless of the amount of dialog instances available. The message server logs are kept on the dev_ms developer trace and if there is an issue with the message server it will be pretty obvious because you will not see a dev_disp trace.

Dispatcher next

Ahhh the Dispatcher!… well, the dispatcher dispatches (ha!), Nah, seriously… The dispatcher job is to receive the requests and direct them to an available suitable work process. During start-up you can see how the work processes are invited to start in the dev_disp developer trace. If something was to go wrong the only thing you will find in dev_disp is that the work processes died. Usually no reason is ever given for the failure to launch in this trace, but one dev_w* developer trace for each dialog process is created and populated in the process.

The dialog processes

This is where you’ll find the root of the problem 99.9% of the time. Why?…  Each dialog process has a dedicated memory area and a dedicated connection to the database layer. If something is going to go wrong it will most likely happen here. Each work process has its own developer trace dev_w* where you will find detailed information on the error.

So the logical troubleshooting sequence, in a nutshell is…

  • Check connection to the database with a quick R3trans –d command, it’s the quickest and simplest way to discard DB availability as the issue.
  • Go to the work directory and check the developer traces. If the dev_w* logs exist it means that the message server and dispatcher started and the issue is in the work process logs..
  • If the dispatcher and work process developer traces are not created then your issue is in the message server developer trace.

The next time you find a start-up issue I’m hoping that these simple steps might mean we can dispense with the crystal ball 😉

Love to hear your comments.

 

Follow-up blog Basic start-up troubleshooting JAVA – the logical sequel!

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      Author's profile photo Former Member
      Former Member

      Knowledgeable document for Freshers in SAP BASIS, escpecially helpful in Operation & maintenance projects.....

        Cheers........... Juan!!!!!!!!!!!!!!!

      Thanks

      Sumit

      Author's profile photo Akshay Gupta
      Akshay Gupta

      Juan,

      What a wonderful troubleshooting tip.

      Usually when something goes wrong in the startup of the system and the development/biz. team is firing you with calls/emails about the system's availability, most of the time is spent in work directory catting the logs and trying to figure out the issue and 1st thing that went wrong.

      Next time on wards, I will follow the trail so that the user's don't have to loose their cool.

      • Go to the work directory and check the developer traces. If the dev_w* logs exist it means that the message server and dispatcher started and the issue is in the work process logs..
      • If the dispatcher and work process developer traces are not created then your issue is in the message server developer trace.

      Regards,

      Akshay.

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Simple, quick, effective... 😀

      Author's profile photo Former Member
      Former Member

      Hi Juan,

      Very nice document.

      Small addition .. In the home directory of SIDADM it writes some files in Unix apart from work directory which gives some more information. Like startDB.log etc.

      I would request you to publish similar document for Java as well as part 2 😉

      Thanks,

      Jagadish.

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Yes, a java one its on the make... thanks for your comment

      Author's profile photo Former Member
      Former Member

      Juan,

      Very good, knowledgeable document.

      Regards,

      Ganesh N

      Author's profile photo Former Member
      Former Member

      Hi Juan,

      Guess I'll be pasting this link in to a few of the questions we get posted over the coming months... 

      Cheers,

      Graham

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Hopefully it will guide a few new comers to read the logs rather than panic 😀

      Author's profile photo Former Member
      Former Member

      usefull

      Author's profile photo Former Member
      Former Member

      Hi,

      Very userful document.

      Regards,

      Sharma TvK

      Author's profile photo shyam kumar
      shyam kumar

      Hi Juan,

      Very useful.. thanks a lot .. 🙂

      Regards,

      Shyam Kumar

      Author's profile photo Farkathulla Cikkanther
      Farkathulla Cikkanther

      Hello Juan,

      Very useful, Thanks...

      Regards,

      Farkath.C

      Author's profile photo JITHIN MOOLIYIL
      JITHIN MOOLIYIL

      Hi Juam,

      Very useful,

      Regards,

      Jithin

      Author's profile photo Former Member
      Former Member

      Very well written to approach SAP System Start up problems.

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Thanks!

      Author's profile photo Former Member
      Former Member

      Hello Juan,

      Excellent, Useful information.

      Appreciated for your efforts with in detailed steps.

      Regards,

      Junead

      Author's profile photo Former Member
      Former Member

      smart tips!....succinctly put ..

      Thanks Juan for this post...keep writing...I look forward to your posts.

      Thanks,

      R

      Author's profile photo Former Member
      Former Member

      Good Resource for All...Many Thanks.

      Best Regards,

      Naresh K.

      Author's profile photo Former Member
      Former Member

      Hi Juan,

      Thanks for sharing this information

      Regards

      Amit

      Author's profile photo Former Member
      Former Member

      Very nice document.. 🙂

      Author's profile photo Yogesh Agarwal
      Yogesh Agarwal

      Hello

      Where do we have to enter R3trans-d?

      Is it in cmd?

      If not, how do I see if db is ON?

      Thanks

      Yogesh.

      Author's profile photo JITHIN MOOLIYIL
      JITHIN MOOLIYIL

      Dear Yogesh,

      Login as <SID>ADM user and open command prompt and run this command

      Regards,

      Jithin

      Author's profile photo Former Member
      Former Member

      Very good Juan, it is very easy and simple.

      SCN users not following these simple steps if they have issues starting SAP and asking the same questions again and again.

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Thanks Sunil

      Author's profile photo Former Member
      Former Member

      Hi Juan,

      Very useful  information.

      Thanks

      Maruthi

      Author's profile photo Former Member
      Former Member

      Excelente esta información

      Gracias Juan

      Saludos

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Gracias!

      Author's profile photo ABHISHEK SINGH
      ABHISHEK SINGH

      Hi Juan ,

      Have you prepared for the java system ???

      i am waiting for the doc for  java System.

      If you have prepared please update the link .

      Regards,

      Abhishek

      Author's profile photo Deeraj Shetty
      Deeraj Shetty

      Hi Juan,

      Very well written!! Thanks for sharing.

      Regards,

      Deeraj Shetty

      Author's profile photo Former Member
      Former Member

      Hi Juan,

      Thanks for sharing. Very nice and useful information!!

      Looking forward for the Java one...

      Thanks,

      Rahul Patki

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Been very busy... I'll do my best to release a basic Java startup troubleshooting guide.

      Regards, Juan

      Author's profile photo Former Member
      Former Member

      Hi ,

      Useful document for freshers regarding issues of system startup.

      Regards,

      sumanth

      Author's profile photo Ashish Kasat
      Ashish Kasat

      Basic but very important steps for troubleshooting ABAP startup issues.

      Thanks,

      Ashish

      Author's profile photo Former Member
      Former Member

      Juan,

      Great article and deeply insight information.

      If you have time, can also extend the troubleshooting scope to cover sapstartsrv process. I have encountered a wired situation that the Windows MMC doesn't display any SAP System to start with. We were all in panic then. Finally we found the culprit is a bad sapstartsrv.exe (the win service failed to start), which was overwritten by wrong kernel binary. Back to the old day I didn't know the link between windows service and MMC.

      this is my 2c

      Author's profile photo Former Member
      Former Member

      usefull information

      Author's profile photo Lucas Santos
      Lucas Santos

      Thanks Reyes, for this so much useful post!

      Author's profile photo Claas Seider
      Claas Seider

      sorry guys,

      but how do I find the so called "dev_w*" files?

      please tell my the directory path I can use to find the files in my dolphin-browser.

      If I try the search function there are no results.

       

      Thanks.

      claas

       

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      /usr/sap/<SID>/<Instance>/work directory

       

      Regards, JP

      Author's profile photo Suraj Brijwani
      Suraj Brijwani

      As simple and erudite as it can get. Thanks to the author Juan.

      Author's profile photo Juan Reyes
      Juan Reyes
      Blog Post Author

      Thanks Suraj, after all this years this small blog is still as relevant as when I wrote it.