Resource Governor, Monitoring and Tracingsiret.ms.mff.cuni.cz/hoksza/teaching/mff/ndbi039/2011... · 2011. 12. 7. · Using SQL Trace through T-SQL • Create a trace by using sp_trace_create.

Resource Governor, Monitoring and Tracing

On SQL Server

Outline

• Resource Governor

– Why use RG?

– Resource pooling

• Monitoring

– Activity monitor

– Underlying DMVs

• Tracing

– How tracing works

What is Resource Governor?

• New feature in SQL Server 2008

• Helps you to manage SQL Server workload and system resource consumption

• Enables placing limits on CPU or memory usage per incoming application request.

• Only available in Enterprise or Developer editions (incl. all evaluation versions)

What is Resource Governor?

• SQL Server 2008 provides Resource Governor, a feature than you can use to manage SQL Server workload and system resource consumption.

• Resource Governor enables you to specify limits on the amount of CPU and memory that incoming application requests can use.

Reasons Behind Resource Governor

• To place limits on resources:

– Threads

– CPU(s)

– Memory

• To have more control over database server.

• To monitor “run-away” queries.

Workload Groups & Classifier

• Ability to differentiate workloads (login, reports, calculations) with importance labels (low, medium, high).

• Limits on:

– Max memory/CPU and timeouts

– Max DOP, max group requests

• Classifier - user-defined function for implementing classification rules.

Resource Pools

• Resource pool: A virtual subset of physical database engine resources.

• You can think of a pool as a virtual SQL Server instance inside of a SQL Server instance.

• Provides controls to specify – Min/Max Memory %

– Min/Max CPU %

– Max DOP

• Workloads are mapped to resource pools N:1.

Resource Governor Schema

Resource Governor Commands

• Enabling or disabling Resource Governor

• Resource Pool and Workload Group creation

Classifier Function Example

Monitoring Resource Governor

• Metadata CVs:

– sys.resource_governor_resource_pools

– sys.resource_governor_workload_groups

– sys.resource_governor_configuration

• Running value DMVs:

– sys.dm_resource_governor_resource_pools

– sys.dm_resource_governor_workload_groups

Activity Monitor

Activity Monitor

• Overview

• Active User Tasks

– Shows information for active user connections to the instance. You can also run profiler from here for a particular process.

• Resource Waits

• Data File I/O

• Recent Expensive Queries

Activity Monitor

• How to open AM?

– CTRL+ALT+A.

– Right-click the instance name, and then select Activity Monitor.

– On the SQL Server Management Studio standard toolbar, click Activity Monitor.

Activity Monitor Underlying DMV

• sys.dm_os_performance_counters

• sys.dm_exec_sessions

• sys.dm_exec_requests

• sys.dm_os_wait_stats

• sys.dm_os_waiting_tasks

• sp_who2 [spid]

sp_who2

SQL Tracing

• Common usages:

– Workload analysis and replay

– Deadlocked/blocked process analysis

SQL Tracing

• Client-side trace using SQL Profiler

– events are streamed from the server, over the network, to the Profiler

• Server-side trace

– using a number of SQL Trace system stored procedures

SQL Trace Terminology

• The following terms describe the key concepts of SQL Trace. • Event

– The occurrence of an action within an instance of the Microsoft SQL Server Database Engine.

• Data column – An attribute of an event.

• Event class – A type of event that can be traced. The event class contains all of the data

columns that can be reported by an event.

• Event category – A group of related event classes.

• Trace (noun) – A collection of events and data returned by the Database Engine.

• Trace (verb) – To collect and monitor events in an instance of SQL Server.

SQL Trace Terminology

• Trace definition – A collection of event classes, data columns and filters that identify the

types of events to be collected during a trace.

• Filter – Criteria that limit the events that are collected in a trace.

• Trace file – A file created when a trace is saved.

• Template – In SQL Server Profiler, a file that defines the event classes and data

columns to be collected in a trace.

• Trace table – In SQL Server Profiler, a table that is created when a trace is saved to a

table.

SQL Trace Architecture

SQL Server Profiler

Introducing SQL Server Profiler

• Microsoft SQL Server Profiler is a graphical user interface to SQL

• You can monitor a production environment to see which stored procedures are affecting performance by executing too slowly.

• To run SQL Server Profiler, on the Start menu, point to All Programs, Microsoft SQL Server 2008, Performance Tools, and then click SQL Server Profiler.

Using SQL Trace through T-SQL

• Create a trace by using sp_trace_create. • Add events with sp_trace_setevent. • (Optional) Set a filter with sp_trace_setfilter. • Start the trace with sp_trace_setstatus. • Stop the trace with sp_trace_setstatus. • Close the trace with sp_trace_setstatus.