CPU Heavily Consumed on HANA 2.0 Rev 61 fixed !!!

[rajeshazmeera]

CPU Heavily Consumed on HANA 2.0 Rev 61 fixed.. This short blog can be handy for you.

 

HANA Database CPU went into very high. Database was up and running able to login from studio.

But users started complaining that system was very slow and taking abnormal time for completion and subsequently login failures occurring. Trace files shows FDA related split jobs are running.

 

CPU behavior during issue.

 

This was causing as HANA DB 2.0 Rev 61 was behaving abnormally due to a particular query related to FDA causing CPU slowness.

This particular hint in sql query was causing issue

 

OPTIMIZER_PHYSICAL_ENUMERATION

CS_ITAB_IN_SUBQUERY

Prefers the column engine ITAB in the subquery.

 

If you see this issue temporary work around  is

prefer_cs_itab_in_subquery_for_param_itab  to set  true and unset this parameter after updating >=62.

Permanent fix is to upgrade HANA Database >=62.

Reference SAP NOTES:-

3149562 - Possible Performance Degradation for FDA Write after Upgrade to SAP HANA 2.0 SPS06

3150702 - SAP HANA 2 SPS06 Revision 062.00