A Little DBA Note on Too Many Trace Files

7/25/2019 A Little DBA Note on Too Many Trace Files

1/6

Generated by Jive on 2016-05-15+02:00

1

SAP HANA and In-Memory Computing: Alittle SAP HANA DBA note on too many tracefiles...

Posted by Lars BreddemannMay 5, 2013

+++ update 7.10.2015 - SPS 10

Since this blog was originally published some time and many SAP HANA revisions passed and there is

meanwhile a supported easy way to do housekeeping around trace files.

There is the ALTER SYSTEM CLEAR TRACES - SAP HANA SQL and System Views Reference - SAP

Librarycommand, that allows the clearing/deletion of trace files from the SQL command.

In addition to that, SAP HANA Studio allows to get rid of old traces via the UI:

And there is more: SAP HANA now automatically compresses and archives old trace files and you can also

trigger that manually (mark the trace files you want to archive, right-click, select 'compress').
http://scn.sap.com/servlet/JiveServlet/showImage/38-84373-804484/2015-10-07_15-30-56.pnghttp://help.sap.com/saphelp_hanaplatform/helpdata/en/20/d12816751910149640d1e144741069/content.htmhttp://help.sap.com/saphelp_hanaplatform/helpdata/en/20/d12816751910149640d1e144741069/content.htmhttp://scn.sap.com/people/lars.breddemann


2/6

SAP HANA and In-Memory Computing: A little SAP HANA DBA note on too many trace files...


2

This means you probably won't be in need of the technique presented in this blog.

Anyhow, for reference it'll stay up here.

+++ update 7.10.2015 - SPS 10

If you have been running SAP HANA for a year or so, spanning multiple revisions, eventually overcoming bugsyou faced in the past, you will invariably end up with an alert similar to this:

"There are currently 1033 diagnosis files.

This might indicate an issue with tracefile rotation, a high number of crashes or another issue. Please check

the diagnosis files."

As a matter of fact, SAP HANA is currently not particularly great at managing all the trace files it creates.

(And don't get me started on the actual contents of those files...).

If things go really bad you may even end up finding error messages like the following in the indexserver trace

files:

[...]

[89705]{0}[0] 2013-04-23 11:48:39.425976 e Basis TraceSegment.cpp(00255) :

Exception while trace file compression:

exception 1: no.2120027 (Basis/Diagnose/impl/TraceSegment.cpp:238)

Trace file compression finished with error: 18446744073709551613

exception throw location:

1: 0x00007fe11c8f5d80 in Diagnose::TraceSegmentCompressorThread::run(void*&)+0x13f0 at

exception.hpp:313 (libhdbbasis.so)

2: 0x00007fe11c951e92 in Execution::Thread::staticMainImp(void**)+0x6b0 at Thread.cpp:457

(libhdbbasis.so)

3: 0x00007fe11c95208d in Execution::Thread::staticMain(void*)+0x39 at Thread.cpp:528 (libhdbbasis.so)

[...]

All too bad, I know, but a quick and easy workaround for this is this:

1. Create another folder, say "old_traces"

2. Move all files older than, say 10 days (or whenever you last upgraded to the most recent revision), to this"old_traces" folder.

3.

Sounds good? Great, then all you got to do is to follow these steps:


3/6



3

1. Logon to the SAP HANA server as SID.

Be aware that in a scale out scenario, you will have to logon to each and every host and perform the following

steps there.

2. Navigate to the trace file folder

For that, just use the predefined shell command alias 'cdtrace'

hansrv123:/usr/sap/HAN/HDB00> cdtrace

hansrv123:/usr/sap/HAN/HDB00/hansrv123/trace>

3. Create the "old_traces" folder

Note that in this example I simply create the "old_traces" folder as a sub-folder of the actual trace folder.You might and probably should create it at a different location, to release the storage space in the trace file

folder.

hansrv123:/usr/sap/HAN/HDB00/hansrv123/trace> mkdir old_traces

4. Move old trace files into the new folder:

This can take some time...

hansrv123:/usr/sap/HAN/HDB00/hansrv123/trace>find . -type f -mtime +10 -print | xargs -I {} mv {} old_traces/

If you find that you don't actually need the trace files any more, you may just go on and delete this folder later

on.

In general, it usually doesn't make sense to keep the trace files generated by older revisions.

Exceptions to this general approach could be, that you faced bugs that you still wait to see fixed or to compare

messages from normal/baseline system operations (think of time required for restart, message output during

restart/shutdown/backup...).

There you have it - now you know!

Cheers,

Lars

6179 Views Tags: sap, support, hana, in-memory, database, sql, in_memory_business_data_management,sap_hana, hde, csa
http://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=csahttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=hdehttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=sap_hanahttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=in_memory_business_data_managementhttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=sqlhttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=databasehttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=in-memoryhttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=hanahttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=supporthttp://scn.sap.com/community/hana-in-memory/blog/tags#/?tags=sap


4/6



4

Muhammed Shaheer MP

May 14, 2016 5:38 PM

Hi Lars Breddemann

Thanks for sharing the note. It makes sense to keep only necessary files under cdtrace

I saw another fact that we need to have old traces still in original directory for few historical informational

queries. Any better thought here?

Thanks,

Shaheer

Sohail Ahmed

Apr 25, 2016 5:22 PM

Thanks Lars...

Sanket Dias

Feb 17, 2016 3:46 AM

Hi Lars,

Very helpful post.. Thanks..

Regards,

Sanket

Shanaka Chandrasekera

Feb 9, 2015 6:43 AM

Hi Lars,

Thank you very much for sharing this.

Regards,

Shanaka.

Fabio Pagotiin response to John Applebyon page 4

Sep 10, 20143:44 PM

Well... I came here thanks to Google.

John Applebyin response to Lars Breddemannon page 4

Sep 10, 2014 3:08 PM

I've noticed comments on a bunch of old blogs too. It's a mystery!

Lars Breddemannin response to John Applebyon page 5

Sep 10, 2014 1:32 PM
http://scn.sap.com/people/fabioluiz.esperatipagotihttp://scn.sap.com/people/sahme26http://scn.sap.com/people/lars.breddemannhttp://scn.sap.com/people/lars.breddemannhttp://scn.sap.com/people/applebyjhttp://scn.sap.com/people/applebyjhttp://scn.sap.com/people/fabioluiz.esperatipagotihttp://scn.sap.com/people/fabioluiz.esperatipagotihttp://scn.sap.com/people/shanaka.chandrasekerahttp://scn.sap.com/people/shanaka.chandrasekerahttp://scn.sap.com/people/sanket.diashttp://scn.sap.com/people/sanket.diashttp://scn.sap.com/people/sahme26http://scn.sap.com/people/sahme26http://scn.sap.com/people/lars.breddemannhttp://scn.sap.com/people/shaheerdbahttp://scn.sap.com/people/shaheerdba


5/6



5

Absolutely - sometimes error messages really indicate problems... .

Funny, lately there is increased activity around old and ancient blog posts again. Did something change with

SCN again???

John ApplebySep 10, 2014 5:22 AM

Tell it how it is Lars! This is a useful tip.

One thing to note is that the too many traces error can be symptomatic of a sick HANA system. I had one

revisit which crashed 1000 times in a row. It had a sick delta log and that crashed the index server on startup.

Though honestly these days such problems are rare.

ABHISHEK SINGH

Sep 9, 2014 7:26 AM

Hi Lars ,

Nice Document !!!

Regards,

Abhishek

Fabio Pagoti

Sep 9, 2014 6:41 AM

Hey! I also happened to realize how many trace files are generated on the system.

I found an option on the Administration view on Hana Studio which can delete trace files. Inside administration

for a particular system, go to "Diagnosis Files" tab. On the top right of the tab, there is a button called "Delete

Trace Files".

Thanks for the blog!

Kulwinder Singh

May 6, 2013 9:36 AM

Hi Lars,

Good one....

Kulwinder

Andy Silvey

May 6, 2013 9:22 AM

Hi Lars,
http://scn.sap.com/people/kulwinder.singhhttp://scn.sap.com/people/fabioluiz.esperatipagotihttp://scn.sap.com/people/singh.abhishek278http://scn.sap.com/people/petr.solberghttp://scn.sap.com/people/petr.solberghttp://scn.sap.com/people/kulwinder.singhhttp://scn.sap.com/people/kulwinder.singhhttp://scn.sap.com/people/fabioluiz.esperatipagotihttp://scn.sap.com/people/fabioluiz.esperatipagotihttp://scn.sap.com/people/singh.abhishek278http://scn.sap.com/people/singh.abhishek278http://scn.sap.com/people/applebyjhttp://scn.sap.com/people/applebyj


6/6



6

that's a nice tip, thanks for blogging.

Andy.

A Little DBA Note on Too Many Trace Files

Documents

Transcript of A Little DBA Note on Too Many Trace Files