Sessions

This resource displays the current number of sessions.

Sessions include both connections and internal background processes like ghost cleanup , checkpoint, and so on. There is a close correlation between connections and sessions, but they are not necessarily the same.

The icons of the listed performance counters in the Statistic Name column changes color to reflect the listed counter's current state. Clicking any performance counter in the Statistic Name column takes you to the Performance Counter Details page for that counter.

If the value of a listed performance counter approaches or crosses the Warning threshold, a yellow band will appear for the listed counter allowing plotted values that cross the threshold to easily be visualized against the yellow band. If the value of a listed performance counter approaches or crosses the Critical threshold, a red band will appear for the listed counter allowing plotted values that cross the threshold to easily be visualized against the red band. Hovering over any time period within the chart will display detailed information about that time period in the tooltip. Hovering over a counter will give you detailed information about that performance counter.

Counter Expert Knowledge

Active Sessions

 

A current connection that is actively processing.

To find information about an active session, use Sp_Who2 Active or Sys.Dm_Exec_Sessions. This is available in SQL 2005 or later.

Potential Issue: Blocking session.

Resolution: Wait until blocking clears or kill the session. If killed, the process would roll back changes. If there are many changes, it could take a while to roll-back.

Inactive Sessions

 

A current connection that is not currently processing.

To find information about an inactive sessions, use Sp_Who2.

Potential Issue: Blocking session.

Resolution: Kill the session if blocking a process needs to finish. If killed, the process would roll back changes. If there are many changes, it could take a while to roll-back.

System Sessions

 

A System initiated connection.

Normally these numbers are less than 50.

Potential Issue: Blocking session.

Resolution: Do not kill system sessions.

User Sessions

 

A user initiated connection.

Normally these numbers are greater than 50.

Potential Issue: Blocking session.

Resolution: Kill the session if blocking a process needs to finish. If killed, the process rolls back changes. If there are many changes, it could take a while to roll-back.

Zooming

You can have the chart show a predetermined time period of data by clicking on any one of the three Zoom buttons in the head of the Zoom column. Alternatively, you can have the chart show a specific date range by dragging the mouse over an area of the chart. The time and date displayed at the top of the resource shows the amount of data currently loaded into the chart. This can be changed by clicking Edit from within the resource.

The Value from Last Poll column shows the most recent data available for the listed statistic.