Collects the Windows "Buffer Cache Hit Ratio" performance counter for each instance of SQL DB Engine on Windows.
Percentage of pages found in the buffer cache without having to read from disk. The ratio is the total number of cache hits divided by the total number of cache lookups over the last few thousand page accesses. After a long period of time, the ratio moves very little. Because reading from the cache is much less expensive than reading from disk, you want this ratio to be high. Generally, you can increase the buffer cache hit ratio by increasing the amount of memory available to SQL Server.
Name | Description | Default Value |
Enabled | Enables or disables the workflow. | Yes |
Interval (seconds) | The recurring interval of time in seconds in which to run the workflow. | 900 |
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 |
Target | Microsoft.SQLServer.Windows.DBEngine |
Category | PerformanceCollection |
Enabled | True |
Alert Generate | False |
Remotable | True |
ID | Module Type | TypeId | RunAs |
---|---|---|---|
DS | DataSource | Microsoft.SQLServer.Windows.DataSource.SqlOsPerformanceReader | Default |
PerfMapper | ConditionDetection | System.Performance.DataGenericMapper | Default |
WriteToDB | WriteAction | Microsoft.SystemCenter.CollectPerformanceData | Default |
WriteToDW | WriteAction | Microsoft.SystemCenter.DataWarehouse.PublishPerformanceData | Default |
<Rule ID="Microsoft.SQLServer.Windows.CollectionRule.DBEngine.BufferCacheHitRatio" Enabled="true" Target="SqlDiscW!Microsoft.SQLServer.Windows.DBEngine">
<Category>PerformanceCollection</Category>
<DataSources>
<DataSource ID="DS" TypeID="Microsoft.SQLServer.Windows.DataSource.SqlOsPerformanceReader">
<MachineName>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/MachineName$</MachineName>
<NetbiosComputerName>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/NetbiosComputerName$</NetbiosComputerName>
<InstanceName>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/InstanceName$</InstanceName>
<ConnectionString>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/ConnectionString$</ConnectionString>
<InstanceVersion>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Version$</InstanceVersion>
<InstanceEdition>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Edition$</InstanceEdition>
<MonitoringType>$Target/Property[Type="SqlDiscW!Microsoft.SQLServer.Windows.DBEngine"]/MonitoringType$</MonitoringType>
<SqlExecTimeoutSeconds>60</SqlExecTimeoutSeconds>
<SqlTimeoutSeconds>15</SqlTimeoutSeconds>
<TimeoutSeconds>300</TimeoutSeconds>
<IntervalSeconds>900</IntervalSeconds>
<ObjectName>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/PerformanceCounterObject$:Buffer Manager</ObjectName>
<PerfInstanceName/>
<PerfParams>
<NameOfHandler>SqlOsPerfCounterReader</NameOfHandler>
<PerformanceCounterObject>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/PerformanceCounterObject$</PerformanceCounterObject>
<CounterConfig>
<CategoryName>Buffer Manager</CategoryName>
<CounterName>Buffer cache hit ratio</CounterName>
<BaseCounterName>Buffer cache hit ratio base</BaseCounterName>
<InstanceSelector>2</InstanceSelector>
<NeedsPrefix>1</NeedsPrefix>
<InstanceIndex>0</InstanceIndex>
</CounterConfig>
</PerfParams>
</DataSource>
</DataSources>
<ConditionDetection ID="PerfMapper" TypeID="SystemPerf!System.Performance.DataGenericMapper">
<ObjectName>SQL DB Engine:Buffer Manager</ObjectName>
<CounterName>Buffer cache hit ratio</CounterName>
<InstanceName/>
<Value>$Data/Property[@Name='CounterValue']$</Value>
</ConditionDetection>
<WriteActions>
<WriteAction ID="WriteToDB" TypeID="SC!Microsoft.SystemCenter.CollectPerformanceData"/>
<WriteAction ID="WriteToDW" TypeID="SCDW!Microsoft.SystemCenter.DataWarehouse.PublishPerformanceData"/>
</WriteActions>
</Rule>