This monitor checks Hash Index Empty Buckets Count and Average Length of the Row Chains in the SQL Database.
This monitor checks the Average length of the row chains in the hash buckets for tables in this database. Since this monitor is a part of an overall standards requirement, an alert would be generated if the setting does not meet the specified standard.
The indexes are used for efficient accessing the data in SQL Server tables. Specifying the right indexes can dramatically improve query performance. The monitor raises a warning alert if empty_bucket_percent is greater than Empty Bucket Percent Threshold, and avg_chain_length is greater than Average Chain Length Threshold, there are too many duplicates, and usage of NONCLUSTERED index would be more appropriate.
See the detailed information:
Indexes for Memory-Optimized Tables
Name | Description | Default Value |
Alert Priority | Defines Alert Priority. | Normal |
Alert Severity | Defines Alert Severity. | Warning |
Average Chain Length Threshold | Threshold for Average Chain Length that indicates the average length of the row chains in the hash buckets. | 100 |
Display index count | The display count of not configured indexes according to the best practice. | 5 |
Empty Bucket Percent Threshold | Threshold for Empty Bucket Percent that indicates the number of empty buckets in the hash index. | 10 |
Enabled | Enables or disables the workflow. | Yes |
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 database connection (seconds) | The workflow will fail and register an event, if it cannot access the database during the specified period. | 15 |
Target | Microsoft.SQLServer.Windows.DBFilegroupFx | ||
Parent Monitor | System.Health.ConfigurationState | ||
Category | ConfigurationHealth | ||
Enabled | True | ||
Alert Generate | True | ||
Alert Severity | Warning | ||
Alert Priority | Normal | ||
Alert Auto Resolve | True | ||
Monitor Type | Microsoft.SQLServer.Windows.MonitorType.DBFilegroupFx.HashIndexAvgChainLength | ||
Remotable | True | ||
Accessibility | Public | ||
Alert Message |
| ||
RunAs | Default |
<UnitMonitor ID="Microsoft.SQLServer.Windows.Monitor.DBFilegroupFx.HashIndexAvgChainLength" Accessibility="Public" Enabled="true" Target="SqlDiscW!Microsoft.SQLServer.Windows.DBFilegroupFx" ParentMonitorID="Health!System.Health.ConfigurationState" Remotable="true" Priority="Normal" TypeID="Microsoft.SQLServer.Windows.MonitorType.DBFilegroupFx.HashIndexAvgChainLength" ConfirmDelivery="false">
<Category>ConfigurationHealth</Category>
<AlertSettings AlertMessage="Microsoft.SQLServer.Windows.Monitor.DBFilegroupFx.HashIndexAvgChainLength.AlertMessage">
<AlertOnState>Warning</AlertOnState>
<AutoResolve>true</AutoResolve>
<AlertPriority>Normal</AlertPriority>
<AlertSeverity>Warning</AlertSeverity>
<AlertParameters>
<AlertParameter1>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.Database"]/DatabaseName$</AlertParameter1>
<AlertParameter2>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/InstanceName$</AlertParameter2>
<AlertParameter3>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/MachineName$</AlertParameter3>
<AlertParameter4>$Data/Context/Property[@Name='Status']$</AlertParameter4>
</AlertParameters>
</AlertSettings>
<OperationalStates>
<OperationalState ID="Success" MonitorTypeStateID="Health" HealthState="Success"/>
<OperationalState ID="Warning" MonitorTypeStateID="Warning" HealthState="Warning"/>
</OperationalStates>
<Configuration>
<MachineName>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/MachineName$</MachineName>
<NetbiosComputerName>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/NetbiosComputerName$</NetbiosComputerName>
<InstanceName>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/InstanceName$</InstanceName>
<ConnectionString>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/ConnectionString$</ConnectionString>
<InstanceVersion>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Version$</InstanceVersion>
<InstanceEdition>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Edition$</InstanceEdition>
<MonitoringType>$Target/Host/Host/Property[Type="SqlDiscW!Microsoft.SQLServer.Windows.DBEngine"]/MonitoringType$</MonitoringType>
<DatabaseName>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.Database"]/DatabaseName$</DatabaseName>
<IntervalSeconds>43200</IntervalSeconds>
<SyncTime/>
<SqlTimeoutSeconds>15</SqlTimeoutSeconds>
<TimeoutSeconds>300</TimeoutSeconds>
<EmptyBucketPercentThreshold>10</EmptyBucketPercentThreshold>
<AvgChainLengthThreshold>100</AvgChainLengthThreshold>
<ErrorTopLines>5</ErrorTopLines>
</Configuration>
</UnitMonitor>