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Purpose

This page is to explain the steps on how to perform checks if the SAP HANA instance is not starting. At the end of this guide, there will be frequently asked questions and common problems that are encountered.

Transparent Huge Page:

 2131662 - Transparent Huge Pages (THP) on SAP HANA Servers

1824819 - SAP HANA DB: Recommended OS settings for SLES 11 / SLES for SAP Applications 11 SP2

1954788 - SAP HANA DB: Recommended OS settings for SLES 11 / SLES for SAP Applications 11 SP3

 

 

Power Saving:

 

1890444 - Slow HANA system due to CPU power save mode

 

Extremely High Memory consumption

 

When you run into system hang Situation please do not restart the Database.

Instead please take a look into SAP Note:  1813020 - How to generate a runtime dump on SAP HANA

Generate 3 to 5 dumps on about 30 seconds part.

Take a look into these dumps to find out which allocator is taking up the most memory. 

Look at SAP Note  1999997 - FAQ: SAP HANA Memory under Q13 for a list of allocator list and their purpose.

 

1858357 - HANA DB: Analysis of wait situations

1989031 - Scheduling the shell script "thrloop.sh"

CPU maxed out

ISSUE:   All CPU cores are completely used system wide

 

1. Check to see if it's HANA process that is consuming most of the CPU.

2. If it is, trigger runtime dump from hdbcons, or use OS tool gstack to trigger thread dump.

3. If it is not, consult with customer DB admin to see if that process can be terminated or restarted.

 

 

1999020 - SAP HANA: Troubleshooting when database is no longer reachable

1999670 - Operating system load analysis using "sar"

File System errors

HANA internal thread deadlock

 

It is possible due to programming error, that HANA's internal threads deadlocked (request handlers), which makes the system appear to hanging and not receiving any request.

This is not the deadlock situation caused by transactions locks, which can be resolved automatically by the database.

 

Run Time Dumps needs to be collect for fix identification.

 

1999998 - FAQ: SAP HANA Lock Analysis

 

 

 

 

 

Related Documents

 

 

 

 

Related Videos:

 

 

Related SAP Notes/KBAs

SAP Note 1732157 - Collecting diagnosis information for SAP HANA

SAP Note 2083715 - Analyzing log volume full situations

SAP Note 1788692 - Index Server crash due to missing LogSegment file

1813020 - How to generate a runtime dump on SAP HANA

1858357 - HANA DB: Analysis of wait situations

1989031 - Scheduling the shell script "thrloop.sh"

1999020 - SAP HANA: Troubleshooting when database is no longer reachable

1999670 - Operating system load analysis using "sar"

1999998 - FAQ: SAP HANA Lock Analysis

  

  

 

 

 

 

 

 

 

 

 

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