cancel
Showing results for 
Search instead for 
Did you mean: 

HANA Nameserver Memory Usage is High than IndexServer

Mithran
Participant
0 Kudos

Dear Guru's,

Thanks in advance.

We are running an SEM System in HANA 2.0 SPS 05 release.

We are facing a strange issue in Development System where Nameserver alone using more memory than Index server.
SYSTEMDB backup size larger than Tenant DB.
Out of 503 GB. We have set a allocation limit to 430. In which 250 + GB is being used by Nameserver

When we try to execute any commands os level also connection is getting time-out.

We also got alerts for Nameserver stating " Memory is not available"

Kindly do the needful.

Thanks & Regards,

Mithran.

Accepted Solutions (0)

Answers (2)

Answers (2)

svkarthikeyantce
Explorer
0 Kudos

Hi Mithran,

Check the Nameserver trace file for active objects and MVCC, garbage collection etc., which increases the usage of nameserver.

Thanks.

Mithran
Participant
0 Kudos

Hi Karthikeyan SalaiVijayan,

Yes I checked and could see backup recovery allocator has consumed about 90+GB.

Thanks & Regards,

Mithran

Amin_Omidy
Active Participant
0 Kudos

Hi Mithran,

As you now Name Server resides in System DB and when it faces issues it impact System DB.

Do you remember any changes happened in OS or HANA recently ?

Do you have any active HANA Replication you can disable to see it will help?

Here is some other possibilities:

Overloading of the Nameserver: This could be due to an increase in the number of open sessions or an increase in the size of data being processed.

Memory Leaks: A memory leak is a type of software bug where the program fails to release memory after it is no longer needed. This can cause the memory usage of the Nameserver to grow over time and eventually lead to high memory usage.

Monitor the Nameserver: You can monitor the Nameserver to see what is causing the high memory usage. You can use tools like SAP HANA Studio or SQL commands to monitor memory usage and identify which processes are using the most memory. Please check to see do you have any OOM logs in HANA you can review

Consider upgrading to new OS kernel: Sometime by updating to the latest OS kernel the issue related to name server can be resolved

Restart the Nameserver: Restarting the Nameserver can help resolve any memory leaks or performance bottlenecks.

Upgrade to a newer release of HANA: If you are running an older version of HANA, upgrading to a newer release may resolve the issue

Hope this helps,

Thanks,

Mithran
Participant

Hi Amin Ondy,

Thank you for the inputs.

We do no have System Replication setup in the affected system.
No changes were done recently and also issue is only with one system which is Development system. QAS / PRD Systems are running with same version and over there we are not facing any issue.

Is there any option to restart Nameserver alone? Only Entire DB restart right ?

Thanks & Regards,

Mithran

Amin_Omidy
Active Participant
0 Kudos

Hi Mithran,

Since other tiers is not facing the same issue I would suggest to cross check the problematic system with other to see is there any difference in version (DB or OS ) and applications using the HANA DB.

A HANA nameserver can be restarted on its own without affecting the system database, as long as the nameserver service is running on a separate host from the system database. However, if the nameserver and the system database are running on the same host, restarting the nameserver could impact the availability of the system database. In such cases, it is usually recommended to restart the entire system, including both the nameserver and the system database.

If you need to restart the nameserver, you can do so using the SAP HANA Cockpit, the SAP HANA Studio, or the command line. The exact steps will depend on the method you choose, but in general, you will need to stop the nameserver service, wait for it to shut down, and then restart it. After restarting the nameserver, you should monitor the system to ensure that it is functioning properly and that clients are able to connect as expected.

If the nameserver is consistently using a large amount of memory for back recovery, it could indicate a problem with the system. For example, it could be a result of a high frequency of system failures, or it could indicate that the system is not properly configured. You can stop or remove system backup and if the high memory utilization the nameserver stops then reconfigure the backup from scratch. There might be issue in disk read/write or other issue in OS side impacting the backup process.

Thanks,