Documentation forSQL Sentry

Performance Overview


The Performance Overview provides a summary of performance data for all watched instances within a group or site. Open the Performance Overview by right-clicking any Group or Site node in the Navigator pane, and selecting Open Performance Overview.

Navigator select instance and Open Performance Overview from the context menu

Note:  You can also open the Performance Overview by selecting the View Performance Stats for All Servers button on the Start page.

View Performance Stats For All Servers

Note:  Selecting the All Targets node opens an overview showing all of the instances that are being watched. Selecting a custom made group node only displays the instances within that group.

Select the Show Avg Over drop-down list box to change the interval for the summarized data.

Performance Overview Show Avg Over drop-down menu

Note:  Select from the following time intervals:

Last Sample Two minutes 10 minutes
30 minutes Two hours Four hours
One day Two days Three days

Select the Show drop-down list box to view either Windows, SQL Servers, or Analysis Services.

Performance Overview Show drop-down list

Double-click on any target or instance to open View Selector. Select Performance Analysis, and then select OK to open Performance Analysis for that target or instance.

Performance Overview View Selector

Select a performance metric in Performance Overview to view a historical graph of that metric.

Performance Overview select an instance in Grid view to see the corresponding graph

Note:  Historical graphs are not available for all metrics. For a detailed description of the various performance metrics, see the Performance Metrics topic.  
Note:  The default setting for the Performance Analysis Overview skin is black, but can be set to standard in the User Preferences window (Tools > User Preferences > Performance Analysis).

User Preferences Performance Analysis Overview Skin setting

Expand targets or instances to see additional information by selecting the Expansion arrow by the desired target or instance.

Additional Toolbar buttons

Performance Overview Toolbar button Description
Expand All button Expands All of the columns in the Performance Overview.
Collapse All button Collapses All of the expanded columns in the Performance Overview.
Expand Warnings button Expands columns that contain metrics that fall outside of the Warning and Critical thresholds.

Failover Simulation

The Failover simulator allows administrators in large or complex environments to see what would happen in the event of several failovers to a single host. This can be especially useful when it comes to capacity management in your environment. When simulating a failover, the simulator displays an aggregation of all the database metrics at the point in time the simulation started. Counters display in red if a failover simulation overwhelms a host. 

Note:  The Failover simulator is only available for monitored instances that contain AlwaysOn availability groups.

Simulate a Failover in the Performance Overview by completing the following steps: 

  1. Select an instance and expand its nodes until you reach the Availability Groups level. 
  2. Right-click on the desired Availability Group, then select Simulate Failover to and the desired target from the context menu.

Performance Overview Simulate Failover to

Note:  An Availability group that's currently the primary produces a context menu that allows you to select the secondary replica that you want to simulate a failover to. You can also simulate failover values from a secondary by right-clicking the secondary replica and selecting Simulate Failover from the context menu.
Note:  You can stop a running simulation at any point. Right click the Availability group running the failover simulation, then select Reset Simulation to stop the simulation. 

Performance Overview Reset Failover

Important:  Once the failover simulation has completed, simulated values display in italics.

Performance Overview Simulated Failover example

3. Select a simulated value to display a historical graph of actual values and a graph of the simulated values. Use these charts to compare your simulated value to the actual value.

Performance Overview Simulated Values graph


In the top right corner of each filter column header is a filter button. Select the filter button Performance Analysis Overview Filter button to open the Custom AutoFilter dialog box.

Performance Overview Filter button

Once selected, choose the operator and value to filter the data. Select Ok to save the custom auto filter.

Performance Overview Custom AutoFilter

Once a filter is set, it appears along the bottom panel of the window. Edits to the filter can be made by selecting Edit Filter and changing the criteria. It can also be disabled by clearing the checkbox or closed completely by using the on the left side of the window.

Performance Overview close filter

Color Indicators

Instance names appear in different colors depending on the status of the instance.

Color Status
Gray (Black in Standard view) Normal
Orange A metric crossed the Warning threshold at or below this level.
Red A metric crossed the Critical threshold at or below this level.
Black (Gray in the Standard view) Instance offline.

Performance Analysis Overview Thresholds

Target Level Normal Warning Critical
Network Outbound Queue
>= Three >= Three for 20 second duration
Network Inbound Errors

> Zero
Network Outbound Errors

> Zero
Memory Free (MB)

CPU Context Switches <5000 times # of cores >=5000 times # of cores >=7500 times # of cores
CPU Processing Time Percent
85-89 >=90
CPU Queue Length

>Two times the number of cores
Target and SQL Server Level

Disk Reads ms/IO <20 20-29 >=30
Disk Writes ms/IO <20 20-34 >=35
SQL Server Level

SQL Server Activity Blocks

> Zero
SQL Server Activity Deadlocks

> Zero
Average Wait Time (ms) CPU Percent

SQL Server Memory Grants Pending

> Two
SQL Server Memory PLE

Disk IO Lazy Writes

SSAS Level

SSAS Formula Engine Queued Jobs
> Zero
SSAS Storage Engine Queued Jobs
> Zero
SSAS Memory Cache Evictions
> Zero
SSAS Storage Temp File (KB)

> Zero
SSAS Memory (KB) Shrunk
> Zero