HANA News Blog

Intel COD / SNC NUMA feature

Matthias Sander + Jens Gleichmann • 28. September 2023

Possible performance degradation or inconsistencies

--Scroll down for English version

Es gibt ein Intel Feature mit dem Namen SNC bzw. COD. Dabei steht SNC nicht für Secure Network Connection, sondern für Sub-NUMA Clustering. COD steht hier nicht für ein Videospiel, sondern für Cluster-On-Die.

Diese Features werden bei neuerer Hardware eingesetzt und wird ca. seit zwei Jahren teilweise standardmäßig aktiviert (beispielsweise bei HPE).

Die Features dürfen unter keinen Umständen mit HANA verwendet werden. Neben Performanceproblemen können ebenso Inkonsistenzen auftreten!

Es wird ein phys. NUMA Node in zwei NUMA Nodes aufgeteilt. Bei einem unserer HANA Health Checks wird neben der Datenbank auch von Storage über Hypervisor und OS einiges überprüft. Bei einem Kunden, für den wir einen solchen Health Check durchgeführt haben, ist uns aufgefallen, dass der ESXi bei einem phys. 2 Sockelserver plötzlich 4 NUMA Nodes anzeigt.

Auf ESX Ebene kann dies mit dem folgenden Kommando überprüft werden:

echo "CPU Packages";vsish -e dir /hardware/cpu/packageList;echo "NUMA nodes"; vsish -e dir /hardware/cpuTopology/numa/nodes

Das Feature kann im BIOS deaktiviert werden (Beispiel HPE).

####################################################English#########################################################

There is an Intel feature called SNC or COD. SNC does not stand for Secure Network Connection, but for Sub-NUMA Clustering. COD does not stand for a video game, but for Cluster-On-Die.

These features are used in newer hardware and have been partially activated by default for around two years (for example at HPE).

The features may not be used with HANA under any circumstances. In addition to performance problems, inconsistencies can also occur!

A physical NUMA node is divided into two NUMA nodes. During one of our HANA health checks, not only the database but also the storage, hypervisor and OS are checked. We noticed at one customer that the ESXi suddenly shows 4 NUMA nodes on a physical 2 socket server.

At ESX level, this can be checked with the following command:

echo "CPU Packages";vsish -e dir /hardware/cpu/packageList;echo "NUMA nodes"; vsish -e dir /hardware/cpuTopology/numa/nodes

The feature can be deactivated in the BIOS (example HPE).

Source

2470289 - FAQ: SAP HANA Non-Uniform Memory Access (NUMA):

Is it possible to use sub-NUMA clustering for SAP HANA?

On BIOS/UEFI level it is possible to define more than one NUMA node per CPU socket (Intel Cluster-On-Die (COD) / sub-NUMA clustering technology). This scenario isn’t supported and can result in SAP HANA persistence corruptions (SAP Note 2116157).

2116157 - FAQ: SAP HANA Consistency Checks and Corruptions

"Unsupported activation of Intel Cluster-On-Die (COD) / sub-NUMA clustering technology"

Details:

Sub-NUMA Clustering by Frank Denneman

< Älterer Beitrag

Neuerer Beitrag >

E-Mail

SAP HANA News by XLC

Why Databases Need Optimizer Statistics – With a Focus on SAP HANA

SAP HANA data statistics for the optimizer

von Jens Gleichmann • 28. Mai 2025

In the world of modern database management systems, query performance is not just a matter of hardware—it’s about smart execution plans. At the core of generating these plans lies a critical component: optimizer statistics. This article explores why databases need optimizer statistics, with particular emphasis on SAP HANA, while drawing parallels with Oracle, Microsoft SQL Server (MSSQL), and IBM DB2.

HANA OS maintenance

von Jens Gleichmann • 27. Mai 2025

Please notice that when you want to run HANA 2.0 SPS07, you need defined OS levels. As you can see RHEL7 and SLES12 are not certified for SPS07. The SPS07 release of HANA is the basis for the S/4HANA release 2023 which is my recommended go-to release for the next years. Keep in mind that you have to go to SPS07 when you are running SPS06 because it will run out of maintenance end of 2023.

HANA performance degradation after upgrade to SPS07+SPS08

Ongoing HANA HEX performance issues with SPS07+SPS08

von Jens Gleichmann • 27. Mai 2025

With SPS06 and even stronger in SPS07 the HEX engine was pushed to be used more often. This results on the one hand side in easy scenario to perfect results with lower memory and CPU consumption ending up in faster response times. But in scenarios with FAE (for all entries) together with FDA (fast data access), it can result in bad performance. After some customers upgraded their first systems to SPS07 I recommended to wait for Rev. 73/74. But some started early with Rev. 71/72 and we had to troubleshoot many statement. If you have similar performance issues after the upgrade to SPS07 feel free to contact us! Our current recommendation is to use Rev. 74 with some workarounds. The performance degradation is extreme in systems like EWM and BW with high analytical workload.

The HANA Optimizer is one of the core components of the HANA database. It determines how SQL is exec

SAP HANA Optimizer - the heart of the performance

von Jens Gleichmann • 25. Mai 2025

A database optimizer behaves similarly to the navigation system in your car. You use various parameters to determine which route you want to take to reach a particular destination. Potential additional costs for tolls and ferries also play a role, as do other limitations such as the vehicle's height, length, and width. From these input parameters, the navigation system determines the optimal route based on current traffic information (traffic volume, construction sites, congestion, accidents, closures, etc.), weather conditions, and the length of the route. This means that with exactly identical input parameters, different routes, costs, and thus different travel times can arise depending on the given conditions.

Is NSE worth the effort or is the better question: Do you know your cost per GB of RAM?

Is the effort for NSE worth it?

von Jens Gleichmann • 18. April 2025

Most of our presentations on data tiering projects end with these typical questions: How much we will save? How fast can it be implemented? Is the effort worth it over time? My counter question: "Do you know how much 1 GB of memory costs your company per month or year?" => how much memory we have to save to be beneficial?

Buchtipp: SAP HANA Deepdive: Optimierung und Stabilität im Betrieb

von Jens Gleichmann und Matthias Sander • 30. März 2025

Unser erster Buch mit dem Titel "SAP HANA Deepdive: Optimierung und Stabilität im Betrieb" ist erschienen.

More time to switch from BSoH to S/4HANA

SAP ERP Extended Maintenance until 2033 - but with conditions

von Jens Gleichmann • 7. Februar 2025

Recently handelsblatt released an article with a new SAP RISE option called SAP ERP, private edition, transition option. This option includes a extended maintenance until the end 2033. This means 3 years more compared to the original on-prem extended maintenance. This statement was confirmed by SAP on request of handelsblatt, but customers receive more details, such as the price, in the first half of the year. This is a quite unusual move of SAP without any official statement on the news page. Just to raise more doubts? Strategy? However a good move against the critics and the ever shorter timeline. Perhaps it is also a consequence of the growing shortage of experts for operating and migrating the large number of systems.

Smart SAP HANA Optimization: Applying NSE for Better Efficiency

von Matthias Sander • 15. Januar 2025

When it comes to optimizing SAP HANA, the balance between performance and cost efficiency is critical. I am happy to share a success story where we used the Native Storage Extension (NSE) to significantly optimize memory usage while being able to adjust the sizing at the end. The Challenge: Our client was operating on a 4 TB memory SAP HANA system, where increasing data loads were driving up costs and memory usage. They needed a solution to right-size their system without compromising performance or scalability. The client wanted to use less hardware in the future. The Solution: We implemented NSE to offload less frequently accessed data from memory. The activation was customized based on table usage patterns: 6 tables fully transitioned to NSE 1 table partially transitioned (single partition) 1 table transitioned by specific columns

SAP HANA NSE - a technical deepdive with Q&A

HANA NSE - technical details Q&A

von Jens Gleichmann • 6. Januar 2025

SAP NSE was introduced with HANA 2.0 SPS04 and based on a similar approach like data aging. Data aging based on a application level approach which has a side effect if you are using a lot of Z-coding. You have to use special BADI's to access the correct data. This means you have to adapt your coding if you are using it for Z-tables or using not SAP standard functions for accessing the data in your Z-coding. In this blog we will talk about the technical aspects in more detail.

The SAP Enterprise Cloud Services Private Cloud Customer Center (PC3) - a new digital delivery

3 years of RISE with SAP: ECS realignment

von Jens Gleichmann • 5. Januar 2025

The SAP Enterprise Cloud Services Private Cloud Customer Center (PC3) - a new digital delivery engagement model dedicated to manage service delivery for RISE with SAP S/4HANA Cloud, private edition customers.