In-Memory OLTP Data Free Space Left

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

Monitors the space available in the database and on the media hosting the database in percentage terms. This monitor does not count the available space for FILESTREAM and In-Memory OLTP data filegroups. Note that this monitor is disabled by default. Use overrides to enable it when necessary.

Knowledge Base article:

Summary

This monitor checks the space which is available in the database and on the media that hosts the database. The available space on the media is considered as part of the available database space only if the autogrowth setting is enabled for at least one of the files in the filegroup. With the 'Health Calculation Mode' override parameter, you can instruct the monitor to check the space based on the percentage term, capacity, or using both at the same time.

Note that this monitor does not count the available space for FILESTREAM and Memory-Optimized Data filegroups.

Causes

An unhealthy state is caused by not having enough free space across In-Memory OLTP database files. Low free space can be caused by:

Use the following links to view the performance data: Database Performance Data

This monitor aggregates the space available for each file within a database depending on each file’s configuration:

No Autogrowth

For a file that has no autogrowth, free space would be the difference between the initial size for a file and the used space.

Autogrowth Enabled

For a file with autogrowth, free space would be calculated as the available free disk space that can be used for extension of the database file with respect to the last autogrowth step size. Because the last autogrowth step size can exceed disk capacity, calculations of the free space are performed as a function of autogrowth step values. For example, if autogrowth is set to 20% on the disk, the size of which is 10 GB and the current database size is 9 GB, the free space will be displayed as 0 GB because the last gigabyte cannot be used.

Low free space for database files that have autogrowth could mean that the file is approaching the limits of the hosting logical drive. For files with autogrowth enabled with a max size, low free space could also mean that the file is approaching the max size specified for a file.

The free space calculations also take into account that the file can also fail to grow if the growth amount of the file is greater than the amount left on disk and that the file cannot grow if the difference between the max size and the current file size is less than the growth amount. In these situations, available free space left on disk is not included as part of the free space because we cannot grow any longer.

Resolutions

This issue can be resolved by:

External

Files and Filegroups Architecture

Overridable Parameters

Name

Description

Default Value

Alert Priority

Defines Alert Priority.

High

Alert Severity

Defines Alert Severity.

Match monitor’s health

Azure Maximum File Size (MB)

The maximum size of data file stored in Azure BLOB Storage. The workflow will consider this value as a maximum storage capacity for each file.

1048576

Critical Threshold (%)

The monitor changes its state to 'Critical' if the value drops below this threshold. The monitor reports the 'Warning' state if the health state is between this threshold and 'Warning Threshold (%)'.

10

Critical Threshold (MB)

The monitor changes its state to 'Critical' if the value drops below this threshold. The monitor reports the 'Warning' state if the health state is between this threshold and 'Warning Threshold (MB)'.

5000

Enabled

Enables or disables the workflow.

No

Generates Alerts

Defines whether the workflow generates an Alert.

Yes

Health Calculation Mode

Defines how to track the health state. The following values are possible:

  • "1" - prioritizes health state tracking based on the 'Threshold' parameter expressed as a percentage term (%).

  • "2" - prioritizes health state tracking based on the 'Threshold' parameter expressed as a capacity metric (MB).

  • "3" - prioritizes health state tracking based on both the percentage term (%) and the capacity metric (MB) thresholds, and uses the worst one to report the state.

1

Interval (seconds)

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

900

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

Warning Threshold (%)

The monitor changes its state to 'Warning' if the value drops below this threshold.

20

Warning Threshold (MB)

The monitor changes its state to 'Warning' if the value drops below this threshold.

10000

Element properties:

TargetMicrosoft.SQLServer.Windows.Database
Parent MonitorMicrosoft.SQLServer.Windows.Rollup.Database.DBSpace
CategoryPerformanceHealth
EnabledFalse
Alert GenerateTrue
Alert SeverityMatchMonitorHealth
Alert PriorityHigh
Alert Auto ResolveTrue
Monitor TypeMicrosoft.SQLServer.Windows.MonitorType.Database.DBSize
RemotableTrue
AccessibilityPublic
Alert Message
MSSQL on Windows: Database In-Memory OLTP data is out of space

Database "{2}" on SQL Server instance "{1}", computer "{0}" is running out of space for In-Memory OLTP data. See the "Alert Context" tab for more details.

Space available: {3}MB ({4}\%).
RunAsDefault

Source Code:

<UnitMonitor ID="Microsoft.SQLServer.Windows.Monitor.Database.InMemoryOltpSizePercent" Accessibility="Public" Enabled="false" Target="SqlDiscW!Microsoft.SQLServer.Windows.Database" ParentMonitorID="Microsoft.SQLServer.Windows.Rollup.Database.DBSpace" Remotable="true" Priority="Normal" TypeID="Microsoft.SQLServer.Windows.MonitorType.Database.DBSize" ConfirmDelivery="false">
<Category>PerformanceHealth</Category>
<AlertSettings AlertMessage="Microsoft.SQLServer.Windows.Monitor.Database.InMemoryOltpSizePercent.AlertMessage">
<AlertOnState>Warning</AlertOnState>
<AutoResolve>true</AutoResolve>
<AlertPriority>High</AlertPriority>
<AlertSeverity>MatchMonitorHealth</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>
<AlertParameter4>$Data/Context/Property[@Name='FxFreeSpaceMB']$</AlertParameter4>
<AlertParameter5>$Data/Context/Property[@Name='FxFreeSpacePercent']$</AlertParameter5>
</AlertParameters>
</AlertSettings>
<OperationalStates>
<OperationalState ID="UnderThreshold1" MonitorTypeStateID="UnderThreshold1" HealthState="Error"/>
<OperationalState ID="OverThreshold1UnderThreshold2" MonitorTypeStateID="OverThreshold1UnderThreshold2" HealthState="Warning"/>
<OperationalState ID="OverThreshold2" MonitorTypeStateID="OverThreshold2" HealthState="Success"/>
</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>
<AzureMaxFileSizeMB>1048576</AzureMaxFileSizeMB>
<HealthCalcMode>1</HealthCalcMode>
<ValuePropertyName>FxFreeSpacePercentMon</ValuePropertyName>
<Value2PropertyName>FxFreeSpaceMBMon</Value2PropertyName>
<Threshold1>10</Threshold1>
<Threshold2>20</Threshold2>
<Threshold21>5000</Threshold21>
<Threshold22>10000</Threshold22>
<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>900</IntervalSeconds>
<SyncTime/>
</Configuration>
</UnitMonitor>