R3trans Error: Rejected as server is temporarily Overloaded

Problem: When checked "R3trans -d" results in error "Rejected as server is temporarily overloaded"

Envronment : SAP ABAP stack and HANA 2.0 SP03

Reason: This problem generally appears when underlying HANA database rejects any connections from the client . HANA would have reached the maximum limit on Global allocation memory. You can check the status from HANA Studio or any monitoring feature.

Use the following SQL statement to diagnose whats occupying the memory

SELECT top 5 Schema_name,

       table_name,

       memory_size_in_main,

       memory_size_in_delta,

       raw_record_count_in_delta,

       last_merge_time

FROM SYS.M_CS_TABLES

where record_count > 0

order by raw_record_count_in_delta desc;

Mini checks can also be used to identify the overview of largest tables.

Solution: 

As a temporary workaround, the "admission_control" parameter that is enabled by default in HANA 2.0 SP03 has to be disabled so that HANA accepts any requests from clients.

or

Unload "tablename" - from DBACOCKPIT / HANA STUDIO can be used to unload any large table to free up  the memory to perform any further actions.

Once the access is gained onto HANA , identify the growth of the respective table/ perform housekeeping on the DB