Hana Database Not Starting due to Index Rebuilding

By | 01/11/2018

Issue: Hana Database Not Starting due to Index Rebuilding

HANA DB Version : 96
Symptoms:
We are facing issues in DB ,SAP HANA database not starting & System is currently down.
Then DBA Finding’s :

We can find trace at OS level at path:

/hana/shared/<SID>/HDB<number>/hanaprd/trace

Trace files are available in the SAP HANA Studio in the Diagnosis Files tab page of the administration screen.

At OS level we can see

hspadm@HANAPRD:/hana/shared/HSP/HDB02/hanaprd/trace> ls -ltr indexserver_hanaprd.30203.executed_statements.008.trc

-rw-r—– 1 hspadm sapsys 11006650 Jul 31 2017 indexserver_hanaprd.30203.executed_statements.008.trc

hspadm@HANAPRD:/hana/shared/HSP/HDB02/hanaprd/trace>

In SAP HANA Studio we can see:

 

Below Finding from Index Server Trace file:
If  Indexserver Having OOM & it’s showing  top allocators IndexRebuildAllocator  in the time of DB restart or not allowing to Start DB due to IndexRebuildAllocator  .Then follow as below.
Top allocators (ordered descending by exclusive_size_in_use).
1: Pool/IndexRebuildAllocator          79991234848b (74.49gb)
Whenever we perform database restart,  HANA triggers index rebuilding procedure of all the indexes at the same time. The rebuilding of each index requires a certain amount of memory which leads to OOM issue.

Solution / Workaround to Hana Database Not Starting due to Index Rebuilding:

We have added the following parameter which stops index rebuild in SAP Hana Database at the time of startup.

indexserver.ini
section:[row_engine]

parameter name: use_jobex_index_rebuild
parameter value: false
Expected Fix:
Once the database is upgraded to version 97, we need to remove the above parameter.


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