What is SUDO in Unix/Linux

What is SUDO

1.    SUDO : Substitute & Do

2.    SUDO is a program in Unix/Linux which allows you to run the commands with the other users’ privileges according to a pre configuration in sudoers file .

3.    By default sudo substitutes root (Super user) and executes the commands followed by it.

4.    It refers /etc/sudoers file (Explained below) for sudo command execution to enforce the security.

SUDO setup

1.    /etc/sudoers file is the configuration file which sudo program reffers each time when it’s called.

2.    In order to have the sudo commands working the same should have been updated in the sudoers file correctly.

3.    For making our SAP files working there were few entries made in the sudoers file.

4.    This entry was made by the Linux/Unix team based on our inputs. 

How to delete an index in SAP

To delete an index.

1> Goto SE14 tcode
2> Enter table name choose tables
3> Select 'Edit'
4> In tools bar select Indexes (F5)
5> Select the indexes one by one
6> Select delete index

Note: You can not delete Primary index from database because it is related with primary key and foreign key concept of RDBMS

ABAP DUMPS (ST22) ANALYSIS IN SAP

NAME OF RUNTIME ERROR	ANALYSIS	SOLUTION
DBIF_RSQL_SQL_ERROR	1.An SQL error occurred when accessing a table.Might be the database system detected a deadlock and avoided it by rolling back your transaction. If possible (and necessary), repeat the last database transaction in the hope that locking the object will not result in another deadlock.	DATA volume is high and the number of sessions triggered were more which led to Deadlock User has schedule the jobs in a smaller data volume with a time period in later schedule and got completed successfully. Release the lock (Need DB02 for analysis not available for offshore.)
TIME_OUT	Time limit exceeded.Some ABAP program has exceeded the maxim permitted runtime.	This error can be avoided by educating the user to schedule the job in background instead of Foreground.(Since it is a business decision to limit the Dialog time limit to 1800 sec). Offshore basis team send mails peridocally to educate end users to schedule the job in background We can send the mails to the functional team to analyze why the reports are run in Dialog mode
SYSTEM_CANCELED	The current program has been terminated by another mode, e.g. with transaction SM50 ,The program "SAPLSCD0 " was terminated manually and no error elimination is necessary..	terminated by user
POSTING_ILLEGAL_STATEMENT	Statement "COMMIT" is not allowed in this form.This is due toError in ABAP application program. .	This happened only one day in the last week. User scheduled program which does not permit the commit in the specified form.SAPOP4 should to work with ABAP technical team. More analysis about the failed jobs could be broken in to functional areas and sent to functional support team and scheduler for further action.     - Need clarification if it is required RnR from basis team as the dump is available for all.
SAPSQL_INVALID_FIELDNAME	One of the field names in the SELECT clause was not recognized.This also due to Error in ABAP application program. .,	It is Program error ABAP team has to resolve. More analysis about the failed jobs could be broken in to funcational areas and sent to functional support team and scheduler for further action. - Need clarification if it is required RnR from basis team as the dump is available for technical team
DYNPRO_SEND_IN_BACKGROUND	Screen output without connection to user.	It is Program error ABAP team has to resolve. Basis team can provide the job details to ABAP team to resolve the issue - Need clarification if it is required RnR from basis team as the dump is available for technical team
SYSTEM_CORE_DUMPED	An SAP System process was terminated by an operating system signal. Possible reasons for this are: 1. Internal SAP System error. 2. Process was terminated externally (by the system administrator). -	Terminated by user
MESSAGE_TYPE_X	An error occurred when the system tried to process the commands from the Automation Queue on the presentation server. There are several possible reasons for this: - The installation of the SAP GUI on the presentation server is faulty or obsolete. - There is an error in the application program - There is an error in the SAPGUI or an integrated control	We have suggest the user to re-Install the SAP GUI upon receipt of trouble ticket
CONVT_NO_NUMBER	Unable to interpret "*0 " as a number.	It is Program error, ABAP team has to handle the exceptions better. Basis team can provide the job details to ABAP team to resolve the issue - Need clarification if it is required RnR from basis team as the dump is available for technical team
COMPUTE_BCD_OVERFLOW	An overflow has been determined in the current arithmetical operation containing operands of type P. Possible causes include: 1. The results field of type P is to small and the result does not fit into it. places. 2. The result or partial result has more than 31 decimal places.	User has to send the correct variant. Basis team can provide the job details to end users - Need clarification if it is required RnR from basis team as the dump is available for user

What is RFC and how to create RFC in SAP SM59

• For business applications, it is essential to communicate and exchange information with other systems. SAP has provided a well defined mechanism called RFC (Remote Function Call) to enable this communication.
• RFC Connections in SAP system are used to establish connection with another SAP system or non-SAP system.
• SM59 transaction code is used to create RFC (Remote Function Call) connection.
• There are different types of RFC connections available in SM59 transaction code.

We mainly used to create 2 types of connections in SM59.

1. ABAP Connections (Type 3)
2. TCP/IP connections (Type T) 

STEPS TO CREATE RFC CONNECTION

1. Select 'Create' icon
2. Provide RFC connection details

• RFC Destination: RFC connection name
• Connection Type: For example 3 or T
• Description: Any short description, purpose of the connection

3. Save the RFC connection

NOTE:

Once the RFC connection is saved, it will take us to the tab 'Technical Settings'.

Technical Settings

• Load balancing

Select Yes, if load balancing is configured in system, else

Select No

• Target host: Either Hostname or IP address of the target system
• System Number: System number of the target SAP system

There are 5 tabs available, in which it is required to fill few of the target system details.

1. Administration:

No input is allowed. It just provides the information on who created/modified the RFC and also the corresponding Date/time.

2. Technical Settings: As explained above

3. Logon and Security:

• Language: Target system language, most of the time it's EN
• Client: Target system client number 
• User ID and Password: User details of Target system

NOTE: 

• In general, RFC users can be of any user type
• For security reasons, it is recommended to use only system users for RFC communications, to avoid access to dialog processes.

• Security options:

• Default setting for 'Trusted System' is 'No'.
• If we need the Trusted RFC connection, select 'Trusted System' as 'Yes'.
• This means, the trusted system doesn't need a password to connect with trusting system
• Trusted system = calling system = Source system
• Trusting system = called system = Target system

Some of the features of this option:

• It provides Cross-system SSO (Single-Sign-On) capability
• Password does not need to be sent across the network
• User-specific logon details of the calling system is checked
• Time-out mechanism for the logon data prevents mishandling of logon data

4. MDMP & Unicode:

• On a Non-Unicode system, the settings under this tab are disabled and no changes are allowed.
• This setting is valid only on an UNICODE system, we have to specify the Unicode settings.

NOTE:

If the SAP system is upgraded from Non-Unicode to Unicode, we need to change the communication type to 'Unicode' on all the applicable RFC connections.

5. Special Options:

This option is very rarely used.  For example

• We can activate options for a trace and slow RFC connections.
• To define qRFC

TESTING THE RFC CONNECTION

• Once all the necessary settings are made and the RFC connection is saved, final step is to make sure the connection is established successfully.
• There are 3 types of connection tests are available.

1. Connection test:    

This is the most important. This test is just to check if the calling system is able to reach the remote system. This authenticates the information provided in the RFC connection for target system.

• If the connection is successful, it displays the table with response times. Else
• An error will be displayed with the reason, and troubleshoot is required to fix the issue.

2. Authorization Test:

This test validates the Client, User ID and Password (provided under 'logon and security' tab for the target system).

• If the Authorization test is successful, it displays the table with response times. Else
• An error will be displayed with the reason, and troubleshoot is required to fix the issue (check the logon details and authorizations)

3. Unicode Test:

• This checks if the Target system is an Unicode system or not

RELATED LINKS:

[1] How to change the TMS RFC in SM59

[2] Important RFC tables and reports like RFCDES

[3] RFC Communication types in SAP

[4] Different types of RFC connections

[5] SAP user types

RFC COMMUNICATION TYPES IN SAP

There are 4 types of RFC communication in SAP

1.      Synchronous RFC

2.      Asynchronous RFC

3.      Transactional RFC

4.      Queued RFC

Synchronous RFC (sRFC) :   
In this type of RFC communication, the calling program waits until the requested processing step on the remote system has ended and then continues to work locally.

In other words, both the systems involved must be available at the time the call is made.

Used for

• communication between systems
• communication between SAP Web Application Server to SAP GUI

Asynchronous RFC (aRFC) : 
In this type of RFC communication, the calling program gives the request to the remote system and immediately continues to work locally. 
The requested processing step is executed on the remote system in isolation.

If the remote system cannot be reached at the time of the call, the asynchronous calls of the RFC client are lost.

Used for

• communication between systems
• For parallel processing

Transactional RFC (tRFC) :  
This type of RFC communication is similar to asynchronous RFC but by allocating a transaction id(TID)  it guarantees  that if a request is sent several times because of network problems  it is processed only once. 
Unlike asynchronous RFC,  in Transactional RFC the remote system does not have to be available at the moment the RFC client program start the call. 
The data is held in the source system until the target system is available.

The report program RSARFCSE is called in the background at regular intervals and tries to place the unsuccessful requests, identified by their transaction id again.

Used for

• Extension of Asynchronous RFC
• For secure communication between systems

Queued RFC (qRFC) :  
This RFC communication is an extension to the transactional RFC. 
In this method, all the requests are queued up(inbound queue and outbound queue) and are processed in a sequence only if it is certain that all preceding calls are processed correctly. 
This method guarantees that all the requests are processed in the sequence in which they are received.

This type of RFCs will be used in SCM (APO) systems for CIF queues etc where requests have to be processed in an order.

Used for

• Extension of the Transactional RFC (tRFC)
• For a defined processing sequence
• Implementation of qRFC is recommended if you want to guarantee that several transactions are processed in a predefined order.

RELATED LINKS:
[1] What is RFC and how to create RFC in SAP
[2] Important RFC tables andreports like RFCDES
[3] RFC Communication types in SAP
[4] Different types of RFCconnections
[5] SAP user types