Gate Way(G)

SAP BASIS FAQ'S

  

                                                  Gate way (G)

A.    It is used to communication between the sap system to non sap system

B.     There will be only 1 gate way for each instance.

C.     In sap level gateway monitoring is - SMGW

D.    In O.S level gate way monitoring is – DEV_RD

Path is – usr\sap\<Sid><instance (number)>\work\dev_rd

E.     We can check also DEV_DISP, i.s dispatcher for log files

F.      usr\sap\<Sid>\instance<number>\work ----> work directory stores log of the work process information in the format of DEV_W*

 

 

Message server (M)

SAP BASIS FAQ'S

 

 

                                    Message server (M)

A.    Message servers handle by the load balancing. It distributes the dispatcher where the load balance is less.

B.     Message server log files are stored in O.S level DEV_MS

Path is – usr\sap\<Sid><instance (number)>\work\dev_ms

C.     In O.S level message server monitoring is – msmon ->cmd

D.    Message server port number is – 36<instance number>

E.     Internal port number is – 39<instance number>

F.      NOTE: sap server has only one message server and enqueue server.

G.    NOTE: application server or dialog instance are same. And central instance is different

Update work process (V)

BASIS FAQ'S

                                              Update work process (V)

 

 A.    It is used to update the database by reading from the temporary tables. It can’t    communicate     with user directly
B.    There are 2 types of update work process. They are v1 and v2
        V1 update is used for critical jobs and V2 update is used for non critical jobs
C.    We need at least one update work process per sap system and we have more than per dispatcher
D.    The update profile parameter name is rdisp\wp_no_vb, rdisp\wp_no_vb2
E.    Update monitoring is – SM13
        Here we can check critical and non critical updates. We can specify date and time
F.    Update program administration – SM14
        This transaction code is used for active to deactivate & deactivates to activate update request and you configure the update servers, update groups and display & monitoring update parameters.
G.    Update temporary table is VB*
1)    Vbmod – update function module
2)    Vbdata – update data
3)    Vberror – update error information
4)    Vbhdr – update header
5)    Vbwrk – work list for mass processing at a time have update
H.    Update status are
1)    Init – the status will be initial.
2)    Run – update is started in main database.
3)    Error – update is thrown into error.
4)    Auto – update is thrown into error due to problem in database space.
I.    Update tables are stored in TBLOD
J.    SAPMV45A: which update work process is going on?

K.    Update types are 3: they are
1)    Local update: Dialog work processes update the directly in Database that is called local update.
2)    Synchronous: Dialog work processes update goes to the temporary table that is called 

        synchronous.                   .
3)    Asynchronous: temporary table goes to database that is called asynchronous
L.    Update statistics are 4:  they are
        Read, Write, Execute and Delete
M.    Update parameters
1)    rdisp\vb_stop_acive: Set to “0” so that update can be deactivated. If the value is set to be “1” update can be activated.
2)    rdisp\vbdelete: This parameter is used to delete the old update requests based on the no. of days. It will delete default 50 days.
3)    rdisp\vbmail: It is used to send an email. It update thrown an error which can be viewed in “SBWP” (“sap business workplace”) based on your user (set to “0” or “1”).
4)    rdisp\vbname : Name of the server running where update are processed
5)    rdisp\vbreorg: It is used to delete the incomplete update request.
        1=delete, 0=no, we can also schedule a background job “RSM13002” but it will delete the update request which are in completed it will be deleted after restarting.
6)    rdisp\vb_delete_after_execution: It is used to delete the update request soon after the execute of the update. Set it to”1” to delete the record (or) “2” to the record will not be deleted. If it is set to “1” the background job “RSM13002” is not required. If not schedule periodically daily during off peak hours.

Dailog Work Process(D)

BASIS FAQ'S

 

                                Dailog Work Process(d)

A.    Dialog work process is used to handle by the user request only

B.    Dialog work process parameter name is – rdisp\wp_no_dia=2
C.    Dialog work processes are minimum 2
       One is user request running another one is distributing the work process
D.    Each request occupies 75mb to 150mb
E.    Dial work process is multiplexive
       Multiplexive means at a time one (or) more use request is running
F.    The user request handle by the dialog work process maximum up to 1800 seconds
G.    If the user request 600 seconds default in that time data is not completed   then user request is  
        session is terminated                     
H.    No of Dialog work process >= No of non Dialog work process
I.    Dialog work process time out parameter is
       rdisp\max_wp_run_timeout=600 to 1800
J.    One dialog work process maximum up to 32 users are we can create
K.    One application server maximum up to 100 work process are we can create
L.       Work process statuses are
          1)    Waiting
          2)    Running
          3)    Error
          4)    Stopped
          5)    Private mode: Dedicated to the particular user
          6)    Sleep: Work process is running but not responding

        Why: Waiting for resources
M.    In sap level work process overview – SM50
N.     In sap level global work process overview – SM66
O.     In O.S level work process overview – dpmon
         Dpmon: when the user could not login to the sap system
P.      In sap level display a list of application server – SM51
Q.     In sm51 transaction to identify the Relesenote, the R/3 kernel, D/B kernel, O.S. Kernel and          support packages information
R.    In sap level version statuses are – system ---> status
S.    In O.S level version we can see – disp+work
T.    How to user request flow?
       User request ---> dispatcher ---> work process ---> dialog work process ---> update the            tables

Enqueue server (E)

SAP BASIS FAQ'S

 Enqueue server (E)

 

A.   Enqueue server handles by the locking and unlocking mechanism
B.   The Enqueue server parameter name is – rdisp\wp_no_enq
C.   Enqueue server table size is minimum of 4MB
D.  We can increase the maximum of size is 100MB
E.   Enqueue table size is enq\table_size=4mb to 100mb
F.   Enqueue server log files will be stored in O.S level Usr\sap\<Sid>instance<number>\log
G.  The Enqueue server work process administrators a lock table in the shared memory area
H.  Enqueue server 4 types they are

1) Shared locks: one user can read the tables and another one user can write the tables
2) Exclusive locks: only a particular user can read it, nobody else can access it
3) Cumulative locks: The same user with different transaction accessing the same table then the lock will be shared with user transactions
4) Optimistic locks: One user lock the table and another user doesn’t have read & access the table permission
I.   Select lock entries – SM12
You can check (or) released the locked entries using transaction is sm12.
If there is a sudden power failure. Some of the users update entry might still be locked. If possible asked the user to logoff first, before deleting the lock entries
J.  Transaction codes: locks and unlocks – SM01
K. Enqueue server lock tables are stored in TLOCK