PRTG Manual: WMI Microsoft SQL Server 2017 Sensor

Performance impact

This sensor has a high performance impact. Stay below 200 WMI sensors per probe. Above this number, consider using multiple remote probes for load balancing.

WoW64

This sensor requires WoW64 (Windows 32-bit on Windows 64-bit) for target systems that run Windows Server 2016.

Credentials

This sensor requires credentials for Windows systems.

Target system

You can only add this sensor to a target system that runs a Microsoft SQL database.

IPv6

This sensor supports IPv6.

Hosted probe

You cannot add this sensor to the hosted probe of a PRTG Hosted Monitor instance. If you want to use this sensor, add it to a remote probe device.

Service

The service that this sensor monitors.

The service name is provided as returned by the SQL server.

Name

The name of the server instance that this sensor monitors.

The display name is provided as returned by the SQL server.

Naming Method

Select whether PRTG automatically selects the name of the WMI class used for monitoring:

• Automatically determine the WMI class name (default): Automatically select WMI class. We recommend this setting.
• Manually enter the WMI class name: Manually enter a WMI class name. Select this option if your server instance returns an error code in automatic mode.

WMI Class

This setting is only visible if you select Manually enter the WMI class name above.

Enter the WMI class name that the sensor uses to monitor the server instance.

Result Handling

Define what PRTG does with the sensor result:

• Discard result (default): Do not store the sensor result.
• Store result: Store the sensor result and the last response in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file names are Result of Sensor [ID].txt and Result of Sensor [ID].Data.txt. This setting is for debugging purposes. PRTG overwrites these files with each scanning interval.

In a cluster, PRTG stores the result in the PRTG data directory of the master node.

Performance Counters

You see a list of different groups of performance counters that the sensor can monitor for the instances that you selected above. Every sensor that PRTG creates for the server instances monitors the performance counters you select here.

• General Statistics (default): Read general performance counters. This shows the number of user connections and the number of logins and logouts per second.
• Access Methods: Read access method counters. This shows the number of full scans, page splits, and table lock escalations (per second).
• Buffer Manager: Read buffer manager counters. This shows the buffer cache hit ratio in percent and the number of database pages and stolen pages.
• Memory Manager: Read memory manager counters. This shows the connection memory, optimizer memory, total server memory, target server memory, and SQL cache memory (in kb).
• Locks: Read locks counters. This shows the number of lock requests and deadlocks (per second), and the average wait time.
• SQL Statistics: Read SQL statistics. This shows the number of batch requests, SQL compilations, and SQL re-compilations (per second).

Depending on your selection, PRTG creates a sensor with the specified channels.

To monitor more than one of the listed groups of performance counters, add the sensor several times for the respective instances.

After sensor creation, this setting shows the performance counter that this sensor monitors.

Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, PRTG displays the last value of the primary channel below the sensor's name. The available options depend on what channels are available for this sensor.

You can set a different primary channel later by clicking below a channel gauge on the sensor's Overview tab.

Graph Type

Define how this sensor shows different channels:

• Show channels independently (default): Show a graph for each channel.
• Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic.
  You cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).

Stack Unit

This setting is only visible if you select Stack channels on top of each other above.

Select a unit from the list. PRTG stacks all channels with this unit on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.

Average Wait Time

The average amount of wait time for each lock request that resulted in a wait

Batch Requests/Sec

The number of Transact-SQL command batches received. This statistic is affected by all constraints (such as input/output, number of users, cache size, or complexity of requests). High batch requests mean good throughput.

Buffer Cache Hit Ratio

The 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 since an instance of SQL Server was started. 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.

Connection Memory (KB)

The total amount of dynamic memory the server is using for maintaining connections

Database Pages

The number of pages in the buffer pool with database content

Number of Deadlocks/Sec

The number of lock requests that resulted in a deadlock

Full Scans/Sec

The number of unrestricted full scans. These can be either base-table or full-index scans.

Lock Requests/Sec

The number of new locks and lock conversions requested from the lock manager

Logins/Sec

The total number of logins started

Logouts/Sec

The total number of logout operations started

Optimizer Memory (KB)

The total amount of dynamic memory the server is using for query optimization

Page Life Expectancy

The number of seconds a page stays in the buffer pool without references

Page Splits/Sec

The number of page splits that occur as the result of overflowing index pages

SQL Cache Memory (KB)

The total amount of dynamic memory the server is using for the dynamic SQL cache

SQL Compilations/Sec

The number of SQL compilations per second. Indicates the number of times the compile code path is entered. Includes compiles because of recompiles. After the SQL Server user activity is stable, this value reaches a steady state.

SQL Recompilations/Sec

The number of SQL recompiles per second. Counts the number of times recompiles are triggered. In general, you want the recompiles to be low.

Stolen Pages

The number of pages used for miscellaneous server purposes (including procedure cache)

Table Lock Escalations/Sec

The number of times that locks on a table were escalated

Target Server Memory (KB)

The total amount of dynamic memory the server can consume

Total Server Memory (KB)

The total amount of dynamic memory that the server is using

User Connections

The number of user connections. Because each user connection consumes some memory, configuring overly high numbers of user connections could affect throughput. Set user connections to the maximum expected number of concurrent users.