Auto Update Statistics Async Configuration

Microsoft.SQLServer.Windows.Monitor.Database.AutoUpdateStatAsyncConfiguration (UnitMonitor)

Monitors the Auto Update Statistics Asynchronously setting for the database. Note that this monitor is disabled by default. Use overrides to enable it when necessary.

Knowledge Base article:

Summary

This monitor checks the Auto Update Statistics Asynchronous database setting. Since this monitor is part of the overall standard requirements, an alert would be generated if the setting does not meet the specified standard.

Configuration

When the Auto Update Statistics Asynchronous setting is ON, statistics updates for the AUTO_UPDATE_STATISTICS option are asynchronous. The query optimizer does not wait for statistics updates to complete before it compiles queries. Setting this option to ON has no effect unless AUTO_UPDATE_STATISTICS is set to ON.

AUTO_UPDATE_STATISTICS_ASYNC {ON | OFF}

Causes

A warning alert will be raised if the option does not match the required setting. Out of the box, the monitor is configured to alert when this setting is set to 'ON'.

The reason this database option is OFF by default is for backwards compatibility with existing applications. Since queries do not wait or block for statistics updates, there is a chance for temporary changes in performance if a query compiles and runs with old statistics. After the statistics are done updating, the same query would recompile against the updated statistics before the next run. But while the stats are updating, the query might have momentary performance problems since it was compiled against old statistics.

ASYNC update is probably the best choice for most applications since it minimizes blocking and waiting overall. Consider turning it ON, and if it works for your application, then disable this unit monitor.

Resolutions

This issue may be resolved by:

Alternatively, if this monitor is not of concern for this database:

External

See the detailed information about this setting: ALTER DATABASE SET Options (Transact-SQL)

See also Using Statistics to Improve Query Performance

Overridable Parameters

Name

Description

Default Value

Alert Priority

Defines Alert Priority.

Normal

Alert Severity

Defines Alert Severity.

Warning

Enabled

Enables or disables the workflow.

No

Expected Value

Expected value of database configuration setting. To view the set of applicable values please refer to "Configuration" section of the knowledge base article of this monitor.

OFF

Generates Alerts

Defines whether the workflow generates an Alert.

Yes

Interval (seconds)

The recurring interval of time in seconds in which to run the workflow.

43200

Synchronization Time

The synchronization time specified by using a 24-hour format. May be omitted.

 

Timeout (seconds)

Specifies the time the workflow is allowed to run before being closed and marked as failed.

300

Timeout for query execution (seconds)

The workflow will fail and register an event, if the query execution takes longer than the specified period.

60

Timeout for database connection (seconds)

The workflow will fail and register an event, if it cannot access the database during the specified period.

15

Element properties:

TargetMicrosoft.SQLServer.Windows.Database
Parent MonitorMicrosoft.SQLServer.Windows.Rollup.Database.AutomaticConfiguration
CategoryConfigurationHealth
EnabledFalse
Alert GenerateTrue
Alert SeverityWarning
Alert PriorityNormal
Alert Auto ResolveTrue
Monitor TypeMicrosoft.SQLServer.Windows.MonitorType.Database.DBConfigurationStatus
RemotableTrue
AccessibilityPublic
Alert Message
MSSQL on Windows: Auto Update Statistics Async Configuration Error
The Auto Update Statistics Asynchronously setting for database "{2}" on SQL Server instance "{1}", computer "{0}" is not set according to the best practices.
RunAsDefault

Source Code:

<UnitMonitor ID="Microsoft.SQLServer.Windows.Monitor.Database.AutoUpdateStatAsyncConfiguration" Accessibility="Public" Enabled="false" Target="SqlDiscW!Microsoft.SQLServer.Windows.Database" ParentMonitorID="Microsoft.SQLServer.Windows.Rollup.Database.AutomaticConfiguration" Remotable="true" Priority="Normal" TypeID="Microsoft.SQLServer.Windows.MonitorType.Database.DBConfigurationStatus" ConfirmDelivery="false">
<Category>ConfigurationHealth</Category>
<AlertSettings AlertMessage="Microsoft.SQLServer.Windows.Monitor.Database.AutoUpdateStatAsyncConfiguration.AlertMessage">
<AlertOnState>Warning</AlertOnState>
<AutoResolve>true</AutoResolve>
<AlertPriority>Normal</AlertPriority>
<AlertSeverity>Warning</AlertSeverity>
<AlertParameters>
<AlertParameter1>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/MachineName$</AlertParameter1>
<AlertParameter2>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/InstanceName$</AlertParameter2>
<AlertParameter3>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.Database"]/DatabaseName$</AlertParameter3>
</AlertParameters>
</AlertSettings>
<OperationalStates>
<OperationalState ID="ConfigurationValueOK" MonitorTypeStateID="ConfigurationValueOK" HealthState="Success"/>
<OperationalState ID="ConfigurationValueNotOK" MonitorTypeStateID="ConfigurationValueNotOK" HealthState="Warning"/>
</OperationalStates>
<Configuration>
<MachineName>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/MachineName$</MachineName>
<NetbiosComputerName>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/NetbiosComputerName$</NetbiosComputerName>
<InstanceName>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/InstanceName$</InstanceName>
<DatabaseName>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.Database"]/DatabaseName$</DatabaseName>
<ConfigName>AutoUpdateStatAsync</ConfigName>
<ExpectedValue>OFF</ExpectedValue>
<ConnectionString>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/ConnectionString$</ConnectionString>
<InstanceVersion>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Version$</InstanceVersion>
<InstanceEdition>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Edition$</InstanceEdition>
<MonitoringType>$Target/Host/Property[Type="SqlDiscW!Microsoft.SQLServer.Windows.DBEngine"]/MonitoringType$</MonitoringType>
<SqlExecTimeoutSeconds>60</SqlExecTimeoutSeconds>
<SqlTimeoutSeconds>15</SqlTimeoutSeconds>
<TimeoutSeconds>300</TimeoutSeconds>
<IntervalSeconds>43200</IntervalSeconds>
<SyncTime/>
</Configuration>
</UnitMonitor>