Error
Error Code:
601
SAP S/4HANA Error 601: Too Many Session Variables
Description
Error 601, ERR_API_TOO_MANY_SESSION_VARIABLES, indicates that an application or process interacting with SAP S/4HANA has attempted to set more session-specific variables than the system allows. This typically occurs during complex API calls or when an application's session management exceeds configured limits, leading to resource exhaustion.
Error Message
ERR_API_TOO_MANY_SESSION_VARIABLES
Known Causes
4 known causesComplex API Integration
An application or integration is making API calls that require an excessive number of session variables to be maintained simultaneously.
Misconfigured Session Management
The application or system interacting with SAP S/4HANA is not correctly managing or releasing session variables, leading to an accumulation.
Inefficient Application Logic
Faulty or inefficient application logic, such as unchecked loops or recursive functions, can rapidly consume session variable limits.
Outdated API Client/Library
Using an older or incompatible API client or library might lead to inefficient session variable handling or unsupported practices.
Solutions
3 solutions available1. Identify and Close Stale User Sessions medium
Terminate inactive or problematic user sessions that are consuming excessive session variables.
1
Log in to the SAP S/4HANA system with an administrator role (e.g., SAP_ALL, SAP_NEW).
2
Access the SM04 transaction (User List).
3
Review the list of logged-in users. Look for users with an unusually high number of sessions or sessions that have been idle for an extended period.
4
For suspected problematic sessions, right-click on the user and select 'End Session'. Confirm the action when prompted.
5
Alternatively, use the SM12 transaction (Close Lock Entries) to identify and delete session-related entries if SM04 is insufficient or if you suspect underlying lock issues.
6
Monitor the system to see if the error 601 is resolved after closing sessions.
2. Analyze and Optimize Custom ABAP Programs advanced
Investigate custom ABAP code for inefficient session variable usage or memory leaks.
1
Identify recent custom ABAP developments or changes that might coincide with the occurrence of error 601.
2
Use the ABAP runtime analysis tool (SE30 or SAT) to profile the execution of suspect programs. Pay close attention to memory consumption and the number of internal session variables created.
3
Review ABAP code for the proper closing of internal sessions (e.g., using `CALL TRANSACTION ... USING ...`) and the release of memory resources. Ensure that global variables and internal tables are cleared when no longer needed.
REPORT Z_SESSION_CLEANUP.
DATA: lv_t_data TYPE STANDARD TABLE OF some_type.
START-OF-SELECTION.
...
" Process data and populate lv_t_data
...
" Explicitly clear if no longer needed
CLEAR lv_t_data.
REFRESH lv_t_data.
" If using CALL TRANSACTION, ensure it's properly managed
" DATA: ls_bdcdata TYPE bdcdata.
" CALL TRANSACTION 'SMEN' USING ls_bdcdata.
" IF sy-subrc = 0.
" " Transaction successful, no explicit session variable cleanup needed for CALL TRANSACTION itself.
" ELSE.
" " Handle errors
" ENDIF.
4
Consult with ABAP developers to implement best practices for session management and memory allocation within their code.
5
Test optimized code thoroughly in a development or quality assurance environment before deploying to production.
3. Tune SAP Gateway Parameters medium
Adjust SAP Gateway parameters to control the maximum number of session variables allowed per gateway instance.
1
Access the SAP Gateway configuration using transaction SMGW.
2
Navigate to 'Goto' -> 'Expert Functions' -> 'Work Processes' -> 'Gateway'.
3
Look for profile parameters related to session management. The most relevant parameter is `gw/max_reg_ex` (maximum number of registered EXEs, which can indirectly impact session variable limits).
gw/max_reg_ex = 100004
If the current value is too low, consider increasing `gw/max_reg_ex`. The optimal value depends on your system's workload and architecture. Start with a moderate increase (e.g., 20-30%) and monitor.
5
Apply the changes. You might need to restart the Gateway or the entire SAP instance for the changes to take effect, depending on the parameter.
6
Monitor system performance and error logs after parameter tuning.