Symptom
From time to time HANA DB system is unresponsive for some seconds.
Sometimes, in a HANA System Replication environment, unresponsive symptom will lead to "HANA_CALL timed out" error in HANA traces.
Looking into indexserver trace file, you can find error message about "un-collected versions" and memory shrink information as follows:
-------------------------------------------------------------------------------------------------------------------------------------------------------
[368913]{-1}[-1/-1] 2022-07-02 05:33:04.536238 e KernelSentinel KernelSentinelJob.cpp(01483) : There are too many un-collected versions on table 'SAPABAP.BKPF' (TABLE_OID = BKPF, NUM_VERSIONS = 12098450, MIN_READ_TIMESTAMP = 32248024052).
The transaction possibly blocks the garbage collection:
CONNECTION_ID = 324506, HOST = hostname:30003, VOLUME_ID = 3,
TRANSACTION_ID = "582", TRANSACTION_TYPE = "USER TRANSACTION",
PRIMARY_TRANSACTION_ID = "-1", PRIMARY_TRANSACTION_TYPE = "",
UPDATE_TRANSACTION_ID = "0", MIN_MVCC_SNAPSHOT_TIMESTAMP = 32248024052,
TRANSACTION TOTAL EXECUTED TIME = 0 sec.
The cursor possibly blocks the garbage collection:
CONNECTION_ID = 324506, CONNECTION_STATUS = RUNNING, HOST = hostname : 30003, IDLE_TIME = 216 sec,
STATEMENT_STATUS = SUSPENDED, STATEMENT_LIFE_TIME = 852772 sec, ISOLATION_LEVEL = READ COMMITTED.
...
IPMM short info:
...
Top "M_HEAP_MEMORY" allocators (component, name, size). Ordered descending by exclusive_size_in_use.
1: Row Store Tables: Pool/RowStoreTables/Version 1.50tb (1658229374984b)
2: System: Pool/RowEngine/RowTableManager/MVCCManager/MVCCAllocator 457.38gb (491116833448b)
...
-------------------------------------------------------------------------------------------------------------------------------------------------------
Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.
Read more...
Environment
- SAP HANA, platform edition 1.0
- SAP HANA, platform edition 2.0
Product
Keywords
SAP HANA, Pool/RowStoreTables/Version, garbage collection, versions, version, row store, idle_cursor_lifetime, idle_connection_timeout, write_transaction_lifetime,garbage collection blockage, indexserver.ini, un-collected versions , KBA , HAN-DB , SAP HANA Database , Problem
About this page
This is a preview of a SAP Knowledge Base Article. Click more to access the full version on SAP for Me (Login required).Search for additional results
Visit SAP Support Portal's SAP Notes and KBA Search.