- Sap Parameter Id
- Sap Extended Memory (em) Parameter
- Sap Extended Memory Parameter
- Sap User Parameters
- Sap Extended Memory Parameters
Parameter em/initialsizeMB. Short text Extended Memory Size. Parameter description Note the operating system dependency for Microsoft Windows. The value specifies the initial size of the memory area that SAP MemoryManagement manages as extended memory. The memory requirements forinteractive users' programs are met from this area. Extended Memory + Free Space in VAS in the SAP work process Note that committed shared memory blocks and the extended memory block (EM) are shared between all virtual address spaces of all SAP work processes. Increasing SAP shared memory blocks by modifying the SAP memory parameters, or reducing the user.
Skip to end of metadataGo to start of metadataPurpose
Explain the SAP parameters involved in the EG shared memory area.
Overview
EG are shared segments shared globally among all work processes.
This is a Memory area that belongs to the Extended Memory (EM). The goal of this Wiki is to explain what are the memory parameter that determine the total size of EG memory.
This is a Memory area that belongs to the Extended Memory (EM). The goal of this Wiki is to explain what are the memory parameter that determine the total size of EG memory.
Extend Global Memory area
The size of the EG is obtained from the total of the parameter values:
- As from 74.X Kernel
em/global_area_MB + abap/shared_objects_size_MB + zcsa/table_buffer_area + zcsa/db_max_buftab
Sap Parameter Id
- Before 74.X Kernel
em/global_area_MB + abap/shared_objects_size_MB
It is required that the address space for EG can be provided by the EM and also by the Operating System.
In order to monitor the EG area it is possible to use different tools:
In order to monitor the EG area it is possible to use different tools:
- SE38 -> RSMEMORY -> EG Overview or
- SE38 → RSMEMORY → EG Consumer (to displays the different consumers using EG memory) as from Netweaver 7.4
- transaction SHMM displays the content of the abap/shared_objects area
- ST02 --> Detail analyis menu --> SAP Memory --> Mode list', in the colunm 'I-Mode Gl' and with the user-id via SM50 you could identify the work process using the EG memory at that time
Different applications use this memory area:
- ITS services that can be monitorized via SITSPMON transaction
- RTM (Runtime monitor) : the memory specified along with profile parameter 'abap/rtm_high_water' is being allocated out of the overall extended global memory area
- Coverage Analizer (transaction SCOV)
- Batch jobs generating spool outputs. If these processes don't issue a commit for sometime there could occupied EG memory
Related Documents
Related SAP Notes/KBAs
Sap Extended Memory (em) Parameter
2148571 - Explanation for higher Extended Memory (EM) and Extended Global Memory (EG) consumption after upgrade to SAP Kernel 7.4x
Sap Extended Memory Parameter
Skip to end of metadataGo to start of metadataAs discussed in Query Performance and Memory Consumption, a BW query uses extended and heap memory. SAP extended memory is the core of the SAP memory management system. Each SAP work process has a part reserved in its virtual address space for extended memory. The parameter ztta/roll_extension specifies how much extended memory can be allocated from the pool to one user context. If the pool is used up, heap memory is allocated. The work process switches to the PRIV mode and is reserved exclusively for the current user context. Hence the most important parameters regarding query execution are abap/heap_area_diaand ztta/roll_extension(or ztta/roll_extension_dia - see note 715277).
You can check how much memory a single query can allocate(maximum) in transaction ST02 → button 'Detail Analysis Menu' → button SAP 'Memory'
So, in total a query on this system cannot allocate more than about 6GB Memory.
If you want to check the memory parameters on your system, you can run the transaction ST02 and then click on the button 'Current Parameters'. In this context the most important paramters are:
- em/initial_size_MB: the total size specified here for the EM should be large enough to contain the total of all user contexts
- ztta/roll_extension: You can restrict the maximum usage of an individual user with this parameter. This prevents one single user from using up the entire extended memory. If the maximum allowed EM memory for a dialog user is used up, heap memory is allocated.
- abap/heap_area_dia: This value specifies how much PRIV memory can be allocated for a user context by a single dialog work process. In this way you can ensure that a single user cannot use the entire available PRIV memory ( abap/heap_area_total).
In case a certain query exceeds these limits, you need to check whether it is possible to increase these paramters(if not, then the query has to be restricted, see Query Performance and Memory Consumption). Please ask your basis adminstrator for help. Check also the online documenation(link below) for further details.
Sap User Parameters
SAP Online Documentation
SAP Notes
Sap Extended Memory Parameters
- 2085980 New features in memory management as of Kernel Release 7.40
- 715277 New instance profile parameters
- 2180736 TSV_TNEW_PAGE_ALLOC_FAILED