lo-cockpit v1 and v2 update

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LO-Cockpit V1 and V2 update

Sabrina Marcado 484 posts since 26 Mar, 2005LO-Cockpit V1 and V2 update 4 Apr, 2005 6:11 AMHi,

Can anyone tell me what is the difference between V1 and V2 update.

I read Robert Negro's weblog and he has stated

1. The serialized V3 update can guarantee the correct sequence for the extraction data of a document only ifthere were no errors in the V2 update. This is because the V3 update only processes update data for which aV2 update has be carried out successfully.

Why is V3 dependent on V2, what is V2 and V1 update?

Ajay Das 2,397 posts since 7 Dec, 2004Re: LO-Cockpit V1 and V2 update 4 Apr, 2005 10:39 AMHi,

V1 - Synchronous updateV2 - Asynchronous updateV3 - Batch asynchronous update

These are different work processes on the application server that takes the update LUW (which may havevarious DB manipulation SQLs) from the running program and execute it. These are separated to optimizetransaction processing capabilities.

Taking an example -If you create/change a purchase order (me21n/me22n), when you press 'SAVE' and see a success message(PO.... changed..), the update to underlying tables EKKO/EKPO has happened (before you saw the message).This update was executed in the V1 work process.There are some statistics collecting tables in the system which can capture data for reporting. For example, LIStable S012 stores purchasing data (it is the same data as EKKO/EKPO stored redundantly, but in a differentstructure to optimize reporting). Now, these tables are updated with the txn you just posted, in a V2 process.Depending on system load, this may happen a few seconds later (after you saw the success message). Youcan see V1/V2/V3 queues in SM12 or SM13.



V3 is specifically for BW extraction. The update LUW for these is sent to V3 but is not executed immediately.You have to schedule a job (eg in LBWE definitions) to process these. This is again to optimize performance.

V2 and V3 are separated from V1 as these are not as realtime critical (updating statistical data). If all theseupdates were put together in one LUW, system performance (concurrency, locking etc) would be impacted.

Serialized V3 update is called after V2 has happened (this is how the code running these updates is written) soif you have both V2 and V3 updates from a txn, if V2 fails or is waiting, V3 will not happen yet.

BTW, 'serialized' V3 is discontinued now, in later releases of PI you will have only unserialized V3. (This isexplained nicely in the weblog).

hope this helps,

cheers,Ajay

Sabrina Marcado 484 posts since 26 Mar, 2005Re: LO-Cockpit V1 and V2 update 4 Apr, 2005 5:18 PMHi Ajay,

Thankyou very much that was a very good answer, but I have another question

There are following tables

1. Application tables (R/3 tables)2. Statistical tables (for reporting purpose)3. update tables4. BW queue

to Application tables its V1 update, statistical tables its V2 update and is it that the same information is againredundantly stored in update tables?

How are statistical tables different from update tables. I mean i understood what statistical tables are, myquestion is "Is the same information again redundantly stored in update tables for Collective V3 update to pullthe records to BW Queue".

I mean is V3 collective update same as Synchronous V3 update? How does the records get saved in updatetables?

Please let me know......



Thanks again.


Statistical tables are for reporting on R/3 while update tables are for BW extraction. Is data stored redundantlyin these two (three if you include application tables) sets of table?, yes it is.

Difference is the fact that update tables are temporary, V3 jobs continually refresh these tables (as Iunderstand). This is different from statistics tables which continue to add all the data. Update tables can bethought of as a staging place on R/3 from where data is consolidated into packages and sent to the deltaqueue (by the V3 job).

Update tables can be bypassed (if you use 'direct' or 'queued' delta instead of V3) to send the updates (data)directly to the BW queue (delta queue). V3 is however better for performance and so it is an option alongwithothers and it uses update tables.

Statistical table existed since pre BW era (for analytical reporting) and have continued and are in use whencustomers want their reporting on R/3.

The structure of statistical table might be different from the update table/BW queue, so, even though it is basedon same data, these might be different subsets of the same superset.

V3 collective update means that the updates are going to be processed only when the V3 job has run. I am notsure about 'synchronous V3'. Do you mean serialized V3?

At the time of oltp transaction, the update entry is made to the update table. Once you have posted the txn, itis available in the update table and is waiting for the V3 job to run. When V3 job runs, it picks up these entriesfrom update table and pushes into delta queue from where BW extraction job extracts it.

cheers,Ajay

Sabrina Marcado 484 posts since 26 Mar, 2005Re: LO-Cockpit V1 and V2 update 5 Apr, 2005 7:08 AMHi Ajay,

Thankyou very much, sorry i meant serialized V3 not synchronous V3 update.



Are we talking about serialization beween sequence of records in update tables to the sequence in BWQueue?

and

Can you explain little more about the Collective run performance with different languages.

Thanks again.

Sabrina.


The requirement in 'delta' capturing on R/3 side is to be able to capture the delta 'exactly once in order'.

Take an example of the same PO item changing many times in quick succession.

V1 (with enqueue mechanism) ensures that the OLTP tables are updated consistently. Update table gets theseupdate records which may or may not end up in correct sequence (as there is no locking) when it reaches BW.'Serialized V3' was to ensure this correct sequence of update records going from update tables to delta queue(and then to BW).

Since update table records have the timestamp, when the V3 job runs, it can sequence these records correctlyand thus achieve 'serialization'. However, there is a technical problem with this. The timestamp recorded inupdate record is sent by the application server (where user executed the txn) and if there are multiple appservers there might be some inconsistency in their system time which can cause incorrect serialization.

Another problem is in the fundamental design of the V3 process. V3 Job sequences the updates on timestamp,and then processes the update records from update table (to send it to delta queue), but it does so for onelanguage at a time (update record also has user logon language stored). Why this is done is not clear to me,but it is a basic design feature and can not be subverted.

This causes a potential issue if multiple logon languages are used by users. Serialization may not happencorrectly in such a case. Take a case where the first update (based on earliest timestamp) to be processed isin language EN (for same PO item). V3 job is then going to process all the update records of language EN inchronological sequence before going to next language records. If another language update (for same PO item)happened in between two EN language updates, this is going to be processed later after all EN updates areprocessed and thus become out of sequence. The weblog mentions this scenario.



These two constraints remain for 'serialized V3' where 'serialization' couldn't be truly achieved. Hence newerPIs have discarded 'serialized V3' altogether and now you do not have this option (if you are using a newer PI).

If you use 'serialized V3', you have to be clear that the 'serialization' may not always work in the abovetwo scenarios (multi language environment, and multiple app servers or updates to same records in samesecond(as timestamp has granularity upto second level only)).

cheers,Ajay

R Reddy Garudammagari 51 posts since 24 Jun, 2005Re: LO-Cockpit V1 and V2 update 24 Jun, 2005 4:39 PMHI Ajay,

You Explation on V1 V2 AND V3 are Excellent, but I have some questions.In your Discussion, you mentioned that there is some Problems in Fundamental Design of V3 Process.Like

1. If there are multiple app servers in Different time zone, then there might be some inconsistency in theirsystem time which can cause incorrect serialization.

2. V3 Job sequences the updates on timestamp, and then processes the update records from updatetable (to send it to delta queue), but it does so for one language at a time (update record also has user logonlanguage stored). This causes a potential issue if multiple logon languages are used by users.Serialization may not happen correctly in such a case. Take a case where the first update (based on earliesttimestamp) to be processed is in language EN (for same PO item). V3 job is then going to process all theupdate records of language EN in chronological sequence before going to next language records. If anotherlanguage update (for same PO item) happened in between two EN language updates, this is going to beprocessed later after all EN updates are processed and thus become out of sequence.

3. Multiple app servers or updates to same records in same second, then 'serialization' may not Work.Because timestamp has granularity upto second level only.

By seeing this I am afire to use V3, because we deal with Multiple app servers.Can you please tell me from ware you got this Valuable Information. And if you have any documents on thistopic ( Bugs in V3 ) can you please forward those to my mail id ([email protected]) .

ThanksRajesh



Ajay Das 2,397 posts since 7 Dec, 2004Re: LO-Cockpit V1 and V2 update 29 Jun, 2005 11:42 AMHi Rajesh,

The info on limitations of v3 are well documented. I saw it in the SAP's training content on data transfer (it isalso mentioned in Roberto Negro's weblogs here at SDN). I am sorry I do not have this material at hand to mailyou.

You would note that 'serialised V3' is no longer available (in newer PIs) as it was not really serialized intrue sense. As such, you will be using unserialized V3, if at all you are using it. This will have performanceadvantages but as it is unserialized, you need to know whether your data is fine if 'in order' is not followed indata transfer. As long as you know this and are fine with it, V3 is perfectly ok.

cheers,Ajay

Bernd Sieger 66 posts since 18 Jun, 2012Re: LO-Cockpit V1 and V2 update 6 Sep, 2005 9:40 AMPlease feel free to look up OSS note 505700. It explains the reasons why the new update methods of the LOCockpit have been invented and thus the shortcomings of serialized V3 updating.

There is also a .PPT presentation about this topic, but I currently can not provide a link external from SAP.

Hope that helps,Bernd Sieger

Ramz R 288 posts since 3 Aug, 2004Re: LO-Cockpit V1 and V2 update 8 Jun, 2006 10:29 AMHi Ajay, Thank you so much for the useful info. I have learnt new things today. Please always keep posting in such adetailed way.

I would have assigned full points for this info.

Regards,Ramesh



Jason Muzzy 152 posts since 10 Oct, 2005Re: LO-Cockpit V1 and V2 update 12 Jan, 2007 10:16 PMHere's the PPT that explained the issues with serialized V3 update and introducedthe new direct/queued delta methods: https://service.sap.com/form/sapnet?_FRAME=CONTAINER&_OBJECT=011000358700005772172002E

srikanth shetty 28 posts since 27 Jun, 2005Re: LO-Cockpit V1 and V2 update 29 Jun, 2005 11:24 AMHello Ajay

your response on v1 and v2 is very informative. i really appreciate it..Regardssrikanth

Rama B 214 posts since 5 Sep, 2006Re: LO-Cockpit V1 and V2 update 8 Feb, 2007 9:15 PMHi Ajay,

Your explanation is great, I cant resist my temptation to congratulate u, I have been trying to understand thesame for the past 2 months, but i coudnt, now ur answers dymystified my doubts!!! thanks a lot.

by the by My mail id is [email protected]; Can u please give ur mail id, so that i can be very greatful to u.please give ur mail id.

thanks & regards...

Sabrina Marcado 484 posts since 26 Mar, 2005Re: LO-Cockpit V1 and V2 update 5 Apr, 2005 10:25 PMHi Ajay,

Thanks again, I cannot stop asking you questions. I read Robert Negro's article 5-6 times and since I don'tknow anything about R/3 there are few things even after reading several times, things just don't make anysense for me(because i don't know the terminology).

I have more questions on direct and queued delta from Negro's article, if you happen to know the answersplease let me know. I will be posting them in an hour or two.



ThanksSabrina.

sap novice 134 posts since 3 Oct, 2006Re: LO-Cockpit V1 and V2 update 14 Mar, 2007 7:32 PMHi ajay,

I was reading your replies for the above thread.Really appreciate the effort and time you put in to share yourknowledge out here.it really helped me understand the process involved in LO Cockpit.

However i still have some questions and i thought who better person than you to get it confirmed from.

V1 Update-Fills up the Transaction tables when the transaction has been enteredV2 Update-Fills up the statistical tables which are used for reportig in R/3.working in BW we are not concerendabout statistical tables.V3 Update- is the periodic process to get the data into the delta Queue where on Delta is brought into BWsystem.

Where does Update table,Setup table come into picture and how are they filled up?Does the update table andsetup table get filled up simultaneously as the transaction table.

thanks in advance

Ajay Das 2,397 posts since 7 Dec, 2004Re: LO-Cockpit V1 and V2 update 14 Mar, 2007 8:46 PMYour statement on V1, V2 and V3 are correct.

Setup tables are outside of this process. These are used to extract all the historical data from application tableto BW. Before your BW delta extraction is active, you need to bring all the old data to BW first. V3 (or otherdelta mechanism) will bring you what is being posted in R/3 after delta has been init. However, to bring all theold data, you load relevant data from application tables to setup tables (using SAP provided report programs).When you do an init, data is read from these tables and loaded to BW. Then onwards, delta process takesover. You can say setup tables are a one-time use kind of table.

Update tables (VBHDR, VBDATA, VBLOG) are central to SAP update mechanism. Everytime there is anupdate that goes to update task (say from the dialog txn), it writes this LUW (eg think of it as one INSERTwith all the values for the table being updated) to these tables - you can check it in any R/3 system. Updatetasks routinely pick up these records and post the DB update and remove the record from these table. A V1update record is processed by V1 update process which is triggered immediately by the end of the dialog



process. A V2 update record is processed by V2 work process which runs after the V1, and a V3 update recordis processed by the batch run of V3 process job.

Depending on how you inserted the record (you called the update in V1 or V2 or V3 update taks ) the updaterecord will accordingly be in these update table and refreshed once they are processed by respective workprocess. If for example you have setup a V3 process and activated it, and the job hasn't run while you haveposted some txns for this, you will see these V3 records in update table.

This is what I remember - it has been a while that I looked at it. Others may add / correct it.

cheers,

sap novice 134 posts since 3 Oct, 2006Re: LO-Cockpit V1 and V2 update 15 Mar, 2007 4:08 PMHi ajay,

the update tables still confuses me.But i got the confirmation rgad the V1,V2,V3 updates.

thanks

It would be great if you could explaination on update tables as u did for V1,V2 updates in your liesure.Would bevery helpful.

Message was edited by: sap novice

Raghavendra Desai 1 posts since 3 Sep, 2005Re: LO-Cockpit V1 and V2 update 3 Sep, 2005 4:40 PMHi Ajay

The concept described is too good.I have been working on BW for last 6 months.Actually i am SDFunctional.As per youApplication Tables are populated in v1 work process.Statistics tables are populated in V2 work process after some time of V1.what about Update Tables.these are updated in which work process.What i feels is in V2 process.Is it right ?Also in LO cockpit we fill some setup tables.For egUsing Transaction OLI1BW for Inventory Management modulewe fill some set up tables.which are this tables.Are these the update tables.It will of great help if u clear my doubts.waiting for your kind reply.



Thanks and RegardsRaghavendra.

sunny d 69 posts since 19 Dec, 2007Re: LO-Cockpit V1 and V2 update 25 Dec, 2007 2:08 AMHi raghavendra,Did you get answer from Ajay fro the doubts u raised.Please do let me know.Thanks,Sunny.

SH A 30 posts since 14 Jun, 2006Re: LO-Cockpit V1 and V2 update 8 Jun, 2006 12:02 PMHi,

Difference between V1, V2 & V3 ...

Synchronous Updating (V1 Update)-->>The statistics update is made synchronously with the document update.While updating, if problems that result in the termination of the statistics update occur, the original documentsare NOT saved. The cause of the termination should be investigated and the problem solved. Subsequently,the documents can be entered again.

Asynchronous Updating (V2 Update)-->>With this update type, the document update is made separately from the statistics update. A termination of thestatistics update has NO influence on the document update (see V1 Update).

Asynchronous Updating (V3 Update) -->>With this update type, updating is made separately from the document update. The difference between thisupdate type and the V2 Update lies, however, with the time schedule. If the V3 update is active, then theupdate can be executed at a later time.In contrast to V1 and V2 Updates , no single documents are updated. The V3 update is, therefore, alsodescribed as a collective update.

Thanks & Regards,SH



simmi sargam 293 posts since 1 Sep, 2004Re: LO-Cockpit V1 and V2 update 12 Jan, 2007 10:06 PMHello Ajay,Your answers are just mind blowing and excellent. It has cleared too many concepts for me.

Thanks a lotSimmi

Karuna Mashetty 1 posts since 4 Jan, 2007Re: LO-Cockpit V1 and V2 update 27 Jan, 2007 6:36 AMHi Ajay,

Your blog on V1,V2 and V3 updates is really excellent.

Karuna

sateesh bandi 13 posts since 25 May, 2008Re: LO-Cockpit V1 and V2 update 18 Jul, 2008 4:56 AMHai Ajay..

This has been a phenominal explanation by you.Thanks.

please please keep posting on different topics.

sateesh

Pixel Pixel 13 posts since 24 Mar, 2006Re: LO-Cockpit V1 and V2 update 13 Feb, 2007 5:25 AMVery Very useful comments from SAP GURU's

Thanks again

shankar sh 30 posts since 20 Dec, 2007Re: LO-Cockpit V1 and V2 update 26 Dec, 2007 6:45 AMHi Sabrina,



Difference between V1, V2 & V3 ...

SYNCHRONOUS UPDATING (V1 Update):

The statistics update is made synchronously with the document update.While updating, if problems that result in the termination of the statistics update occur, the original documentsare NOT saved. The cause of the termination should be investigated and the problem solved. Subsequently,the documents can be entered again.

ASYNCHRONOUS UPDATING (V2 Update):

With this update type, the document update is made separately from the statistics update. A termination of thestatistics update has NO influence on the document update (see V1 Update).

Asynchronous Updating (V3 Update):

With this update type, updating is made separately from the document update. The difference between thisupdate type and the V2 Update lies, however, with the time schedule. If the V3 update is active, then theupdate can be executed at a later time.In contrast to V1 and V2 Updates , no single documents are updated. The V3 update is, therefore, alsodescribed as a collective update.

hOPE IT HELPS U

RegardsShankar

lo-cockpit v1 and v2 update

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