Database Administrators Stack Exchange
Database Administrators Stack Exchange

Questions tagged [numa]

NUMA refers to "Non-Uniform Memory Access", and is a technology for providing RAM that can be accessed faster by the local core or CPU than it can be by other cores present in the computer.

Under NUMA, a processor can access its own local memory faster than non-local memory (memory local to another processor or memory shared between processors). The benefits of NUMA are limited to particular workloads, notably on servers where the data are often associated strongly with certain tasks or users.

See the Wikipedia page on NUMA for more details.

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Does CPU utilization affect the cost of foreign NUMA access?

Scenario Let's assume I have a SQL Server with 4 sockets with each 1 NUMA node. Each socket has 4 physical cores. There is 512 GB of memory total so each NUMA node has 128 GB of RAM. A key table is loaded into the first NUMA node. Question Let's…
xav
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Anyone use SUMA, trace flag 8048, or trace flag 8015?

Recently included SQL Server startup Trace Flag 8048 to resolve a serious spinlock contention issue in a SQL Server 2008 R2 system. Interested to hear from others who have found usage cases where performance value was delivered by trace flag 8048…
sql_handle
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Why is SQL Server setup recommending MAXDOP 8 here?

I'm running SQL Server 2022 RC1 setup on an AWS i3.16xlarge with 2 sockets, 2 NUMA nodes, 32 logical processors per node, 64 logical processors altogether. Setup is recommending MAXDOP 8: But if you click on that link for configuring MAXDOP, the…
Brent Ozar
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Configure RAM for SQL Server and NUMA

Accidental DB admin here. Question: Would you still manually limit max RAM for SQL Server even though the sole purpose of that server is to serve SQL Server database engine only? I have Microsoft Windows 2012 R2 Server, SQL Server 2012 Std, with…
volantis
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Low PLE on NUMA node 000, high on 001

I'm looking at PLE (Page Life Expectancy) across NUMA nodes on our SQL Servers, and came across a rather weird distribution. NUMA node 000 has a very low PLE compared to 001. I'm unsure why this is. I've checked on multiple other SQL Servers in our…
Kasper Brandenburg
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SQL Server detected 2 sockets with 4 cores per socket but only one NUMA node

We have a SQL Server 2012 SP 2 CU 8 instance in a VMWare host. The operating system is Windows Server 2012 R2. Windows Task Manager says that we have two sockets and 8 virtual cores. This number corresponds with the actual hardware beneath the…
Hans Vader
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Why does dm_os_memory_clerks have MEMORYCLERK_SQLCLR values on one NUMA node?

We are using a SQLCLR stored procedure for service broker activation, and I want to monitor the memory used by the CLR code. Looking at sys.dm_os_memory_clerks, I see that only NUMA node 1 has any pages associated with the MEMORYCLERK_SQLCLR type.…
msgisme
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Does RSS Profile have an effect on SQL Server with NUMA setup?

I'm curious whether the RSS Profile which is default NUMAStatic on Windows 2012 R2 could/should be changed for SQL Server with a NUMA setup. Has anyone done performance benchmarks on high load SQL Servers with NUMA or Conservative settings?
Jens D.
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automatic soft NUMA results in odd number of cores

I ran sp_blitz on one of our SQL Server 2016 production servers and one of the findings was that there were CPUs with an odd number of cores. The detailed message indicated this is a really bad NUMA configuration. SQL Server 2016 will use automatic…
John Fowler
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SQLServer 2016 continually increasing stolen memory

We are experiencing a slow growth of Stolen Memory on our database servers over the space of several days. It appears to plateau around 130-140GB, at which point we start having larger problems such as out-of-memory errors, multi-second freezes & AG…
geofftnz
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How big of an impact does NUMA really have?

I was reading up on Non-Uniform Memory Access (NUMA) and I was wondering how much of a difference it can really make? Another way to word that, what level of throughput is required before this becomes beneficial? Also, what type of server do you…
Richard
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4 CPUs of 20 (NUMA node 0) Pegged at 100%

The previous Senior DBA left the company and I was made aware of a server which suffers from multiple problems, largely slowness (all the way from SSMS taking a long time to open, long running queries, and failing SSIS jobs (Data Warehouse), to…
SQL_Deadwood
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NUMA Nodes - MAXDOP - PLE

We have a server with 8 CPUS across 2 NUMAs with hyperthreading enabled. Currently Maxdop is set to 8, but actually should be set to 4 as per the Maxdop section of this article: https://support.microsoft.com/en-us/kb/322385 So we need to change it…
hpk89
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NUMA config - sp_blitz output

I'm trying to learn more about how SQL Server works with NUMA nodes as I noticed something in the output of sp_Blitz that I didn't understand: Node: 0 State: ONLINE Online schedulers: 8 Offline schedulers: 0 Processor Group: 0 Memory node: 0 Memory…
FrugalShaun
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SQL Server not using all NUMA memory with 20 core limit and affinity mask

I have a physical SQL Server 2016 SP1 machine with this spec: CPU Sockets: 2 Cores per socket: 44 Multithreading: Yes Number of cores: 88 RAM: 256 GB SQL Server Max Memory: 240 GB NUMA: CPU1 128 GB CPU2 128 GB We are running…
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