DB Disk Write Latency

Microsoft.SQLServer.Linux.Monitor.Database.DBDiskWriteLatency (UnitMonitor)

Monitors the disk Write latency (ms) from all logical disks which host database files. The monitor is disabled by default. Use overrides to enable it when necessary.

Knowledge Base article:

Summary

Monitors the disk write latency (ms) from all logical disks which host database files.

Causes

The problem may be caused by a disk bottleneck or disk contention.

Resolutions

This issue may be resolved by either:

Overridable Parameters

Name

Description

Default Value

Alert Priority

Defines Alert Priority.

High

Alert Severity

Defines Alert Severity.

Match monitor’s health

Critical Threshold

The monitor will change its state to Critical if the value exceeds this threshold.

25

Enabled

Enables or disables the workflow.

No

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.

900

Number of samples

Indicates how many times a measured value should breach a threshold before the state is changed.

6

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.Linux.Database
Parent MonitorSystem.Health.PerformanceState
CategoryPerformanceHealth
EnabledFalse
Alert GenerateTrue
Alert SeverityMatchMonitorHealth
Alert PriorityHigh
Alert Auto ResolveTrue
Monitor TypeMicrosoft.SQLServer.Linux.MonitorType.Database.DBDiskWriteLatency
RemotableTrue
AccessibilityPublic
Alert Message
MSSQL on Linux: DB Disk Write Latency is over Low Threshold
The database "{2}" on SQL Server instance "{1}", computer "{0}" has disk write latency over the threshold. See the "Alert Context" tab for more details.
RunAsDefault

Source Code:

<UnitMonitor ID="Microsoft.SQLServer.Linux.Monitor.Database.DBDiskWriteLatency" Accessibility="Public" Enabled="false" Target="SqlDiscL!Microsoft.SQLServer.Linux.Database" ParentMonitorID="Health!System.Health.PerformanceState" Remotable="true" Priority="Normal" TypeID="Microsoft.SQLServer.Linux.MonitorType.Database.DBDiskWriteLatency" ConfirmDelivery="false">
<Category>PerformanceHealth</Category>
<AlertSettings AlertMessage="Microsoft.SQLServer.Linux.Monitor.Database.DBDiskWriteLatency.AlertMessage">
<AlertOnState>Error</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>
</AlertParameters>
</AlertSettings>
<OperationalStates>
<OperationalState ID="OverThreshold" MonitorTypeStateID="OverThreshold" HealthState="Error"/>
<OperationalState ID="UnderThreshold" MonitorTypeStateID="UnderThreshold" 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>
<ObjectName>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/PerformanceCounterObject$:TransactionLog</ObjectName>
<CounterName>DB Disk Write Latency (ms)</CounterName>
<PerfInstanceName/>
<ValuePropertyName>WriteLatency</ValuePropertyName>
<Threshold>25</Threshold>
<NumSamples>6</NumSamples>
<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>
<SqlExecTimeoutSeconds>60</SqlExecTimeoutSeconds>
<SqlTimeoutSeconds>15</SqlTimeoutSeconds>
<TimeoutSeconds>300</TimeoutSeconds>
<IntervalSeconds>900</IntervalSeconds>
<SyncTime/>
</Configuration>
</UnitMonitor>