1. Banco de Dados – Planejando um ambiente SQL Server de alta performance e missão crítica
Vitor Fava
Data Platform MVP

2. Agenda Introduction The Life Cycle of a Query
Memory (Physical/Virtual)
CPU Architecture
Storage
SQL Server File Layout

3. Vitor Fava MVP Data Platform Pass Chapter Leader do SQLManiacs
Module 0: Introduction
Course ####y
Vitor Fava
MVP Data Platform
Pass Chapter Leader do SQLManiacs
SQL Server Database Consultant na Pythian
CEO da Vita Database Solutions
Welcome students to the course and introduce yourself. Provide a brief overview of your background to establish credibility.
Ask students to introduce themselves and provide their backgrounds, product experience, and expectations of the course.
Record student expectations on a whiteboard or flip chart that you can reference during class.

4. Introduction
Memory, disk, and CPU are the holy trinity of resources in a Computer system, and memory is first because it’s the area you’re most likely to have an issue with;
Memory issues can cause both disk and CPU saturation;
Storage systems have been confounding database administrators and designers since Microsoft first released SQL Server;
Today DBAs are not only required to design and maintain SQL Server, but are also often pressed into service as storage administrators;
For DBAs working in the enterprise, communication with the server, networking, and especially storage teams are always a challenge;

5. The Life Cycle of a Query

6. Physical Memory
When the term physical memory is used, it’s usually in relation to RAM (random access memory), but it actually also includes the system page file;
It is regarded as the fastest type of storage you can use, but it’s volatile, meaning you lose what was stored when you reboot the computer;
RAM modules is measured in gigabytes per second (GB/s) with nanosecond (ns) response times, whereas hard disk throughput is measured in megabytes per second (MB/s) with millisecond (ms) response times;
It’s also expensive and limited in capacity compared to nonvolatile storage such as a hard disk;

7. Maximum Supported Physical Memory
Feature
Enterprise
Standard
Express (Advanced Services)
Express
Database Engine
Windows Maximum
128 GB
1 GB
Analysis Services
Tabular: 16 GB
MOLAP: 64 GB
N/A
Reporting Services
64 GB
4 GB

8. Virtual Memory
If all the processes running on a computer could only use addresses in physical RAM, the system would very quickly experience a bottleneck.
Windows assigns a virtual address space (VAS) to each process.
This provides a layer of abstraction between an application and physical memory so that the operating system can choose the most efficient way to use physical memory across all the processes;
For example, two different processes can both use the memory address 0xFFF because it’s a virtual address and each process has its own VAS with the same address range.
The size of the virtual address space is determined largely by the CPU architecture.

9. Virtual Memory – x86
The virtual address space for a 32-bit system is only 4GB;
Broken down into 2GB for kernel mode and 2GB for user mode;

10. Virtual Memory – x64
A 64-bit CPU running 64-bit software architecture can manipulate values that are up to 64 bits in length;
Value between 0 and 18,446,744,073,709,551,616 to reference a memory address;
44-bit address bus provides a virtual address space on 64-bit systems of 16TB;

11. Virtual Memory Manager

12. Sizing the Page File
Windows will manage the size of your page file recommending a page file size of 1.5 times the size of RAM;
The primary purpose of a page file is to allow Windows to temporarily move data from RAM to disk to help it manage resources effectively;
When a page file is heavily used, it indicates memory pressure; and the solution is to optimize your memory resources or buy more RAM, rather than to optimize your page file;
If you have disk space concerns on your page file drive, then setting the page file to 50% of total available RAM;

13. SMP
Traditional architecture, every processor has access to every memory bank across a shared system bus to a central memory controller on the motherboard (SMP);

14. SMP

15. Non-Uniform Memory Architecture - NUMA
Non-Uniform Memory Architecture (NUMA) is a hardware design that improves server scalability by removing motherboard bottlenecks;

16. Non-Uniform Memory Architecture - NUMA

17. NUMA – SQL Server’s Use of NUMA
SQL Server creates its own internal nodes on startup that map directly on to NUMA nodes;

18. SQL Server NUMA Memory Configuration

19. Non-Uniform Memory Architecture - NUMA

20. Min and Max Server Memory
Min Server Memory (MB) and Max Server Memory (MB) control the allowable size of all SQL Server’s memory usage;
Look at SQL Server’s maximum usage;
MSSQL$<instance>:Memory Manager\Total Server Memory (KB);
Determine the maximum potential for memory requirements outside SQL Server;
2GB for Windows;
xGB for SQL Server worker threads;
512MB, if you use linked servers, extended stored procedure dlls, or objects created using Automation procedures (sp_OA calls);
1–3GB, for other applications that might be running on the system, such as backup programs or anti-virus software;

21. Lock Pages in Memory
Lock Pages in Memory (LPIM) is used as a work-around for a problem than can occur between Windows and SQL Server;
It was especially bad on older versions of SQL Server, which could run on Windows Server 2003 and earlier;
This is known as aggressive working set trimming and had a devastating effect on SQL Server’s memory allocation — and therefore performance
First set Max Server Memory appropriately;
SQL Server’s buffer pool pages are “locked” and non-pageable so Windows can’t take them when trimming;
SQL Server Error Log: Using Locked Pages in the Memory Manager;

22. Optimize for Ad-Hoc Workloads
When this option is enabled, SQL Server will cache only a plan stub the first time a piece of ad-hoc T-SQL is executed, rather than the full plan;
If SQL Server subsequently tries to reuse that plan, it will be generated again but this time cached in full;
This avoids the scenario of thousands of single-use plans taking up valuable space in cache;

23. The Fundamental Characteristics of Storage

24. The Fundamental Characteristics of Storage
Latency;
IOPS;
Bandwidth;
These three measurements are all related, so you can’t just look at one of them in isolation, without knowing the others;
Storage vendors tend to show their best -case numbers in isolation;

25. Storage Technology
Storage array controllers group disks into volumes called a redundant array of inexpensive disks (RAID);
RAID-constructed volumes offer capacity without failure protection;
RAID 0;
RAID 1;
RAID 5;
RAID 1+0;

26. Storage Technology

27. Storage Tiering

28. Storage Performance Counters
Latency
Average Disk sec/Read
Average Disk sec/Write
IOPS
Disk Reads/sec
Disk Writes/sec
Bandwidth
Disk Read Bytes/Sec
Disk Write Bytes/Sec

29. SQL Server – File Layout
10,000 transactions and 10K SAS drives;
About 140 IOPS, therefore, you need 142 of them;
Design tempdb to be about 20 percent of the expected I/O for the main data files, so you expect 2,000 IOPS;
SATA drives perform sequential operations extremely well, so they are a great candidate for dump drives (RAID 6);
You should completely isolate the log onto its own set of RAID 1+0 SAS disk drives;

30. SQL Server – File Layout
Microsoft recommends the use of a 64KB allocation unit size for data, logs, and tempdb;
When using SQL Server FILESTREAM to store unstructured data, ensure that the partition used to host FILESTREAM data is formatted with an appropriate sector size, usually 4KB;
SQL Server Analysis Services (SSAS) will read and write cube data to small XML files and should therefore also utilize a 32KB-sector size;

31. SQL Server – Disk Layout

32. Disk Benchmark Tools CrystalDiskMark (http://bit.ly/1vm5dPe) SQLIO(
DiskSpd (

33. Referências SQL Server Internal 2012 - Internals & Troubleshooting
Microsoft Windows Clustering: Storage Area Networks
StorPort in Windows Server 2003: Improving Manageability and Performance in Hardware RAID and Storage Area Networks
Virtual Device Interface Specification
Windows Server System Storage Home
Microsoft Storage Technologies – Multipath I/O
Storage Top 10 Best Practices