Overview - Blocking

Blocking – Overview

The color-coded stacked lines of the Events Count histogram display the top three (3) blocking events by Instance that fall within the specified range of time. The selected date range is displayed in the header of the Events Count card.
To examine individual blocking events, the visual display can be changed to further identify which blocks are occurring the most, as follows:

• Use the calendar widget to change the date range (default is last seven (7) days). The selected range is displayed on the card tool bar.
• Use the time widget to change the time interval displayed (Auto is one (1) hour).
• Use the slide toggles to filter the display by hiding or showing top Instance(s).
• Use the Environment, Instance, Database, Login Name, Program, Wait Type, Weekday, and Time of Day drop-down

Filters to change the visualization. Depending on the filter(s) selected, the histogram will display the top three instances for that criteria.

To view any Anomalies:
Hover the cursor over the Anomalies button in the card tool bar. If anomalies exist, the button will be enabled and display the number of anomalies occurring within the specified date range. Click the button to view the Count Anomalies pop-up.

• This pop-up displays when the anomaly Started and Ended, the Instance and Database where it occurred, the Actual and Typical counts and a description of the deviation from the expected value.
• To view an anomaly in the dashboard display, click the 3-Dot icon for that row and click View Anomaly. The histogram will now display the instance with the anomaly highlighted for further investigation.

The data displayed in the Events Count and Unique Blocking Chains cards can also be further focused using Slicers.

Slicers

To filter the data in the dashboard displays, click the Slicer icon [ ///] to the right of the Events Count card. Selections made in the Slicer is reflected in the Filters drop-downs at the top of the screen. The Slicer panel includes filters for:
Top Instances
Where the overview displays only the top three (3) instances, this slicer displays a sortable list of all Instances by Counts.
Top Databases
Displays
Top Object Names
Displays
1.2.3.1.2 Events Count
The histogram in this card displays the top three (3) blocking events by Instance that fall within the specified range of time. To highlight data points, hover the cursor over the stacked, color-coded lines:

• Displays the average number of blocks over the time range below the slide toggles for each top Instance.
• The marker pop-up will display the number of blocking events by date for the selected Instance(s). These values are also displayed below the slide toggles along with totals and averages based on percentage contribution.
• To concentrate the display on a specific time range, using the left button, select the block of time by dragging the cursor over the section of the display. The histogram will display only that time range refinement.
  The data displayed can be further filtered using Time and Day overlays.
  Time and Day Overlays
  To focus the display by the day of the week or by time of day by clicking the checkbox for the desired day or time. To hide the Day and Time cards, click Collapse Overlays below the histogram. Only one overlay can be applied at a time.
  Blocking by Day of Week
• Sunday – Saturday
• Click the checkbox to reset Events Count card to display only that day of week.
  Blocking by Time of Day
• 00:40 – 20:00-24:00
• Click the checkbox to reset Events Count card to display only that time of day.
  1.2.3.1.3 Unique Blocking Chains
  This card displays blocking chain data that can be used to further examine blocking events. To return the SQL Statements in the blocking chain, data is collected from Dynamic Management Views (DMVs) and system tables.
  NOTE: Rather than just looking at individual events, the distinct blocking chains (“strains” within SQL Statements) that occurred the most during the specified interval are aggregated and identified as Unique Statements. Depending on the collection method from the system tables, some SQL Statements may not be available at a server level at the time of collection and will appear at the database level as an orphaned SQL Statements.
  Result-sets are grouped in a searchable table format with sortable columns, as follows:
• The Blocker ID column displays
• The Instance column displays
• The Database column displays
• The Object column displays
• The SQL Statement column displays
• The Events column displays
• The Blocked Statement column displays

Note: Hover the cursor over the column headings to sort the list in ascending or descending order.

Click 3-DOT icon at the right in any row to view additional blocking chain details. See the View Details section for more information.

Blocking chain data can be further focused by using the Group By drop-down menu, as follows.
By Blocker ID:
Displays a sortable list by Blocker ID, Events, and Blocked Statements.

• Click the arrow [>] to the left of the row to display Blocker information further by Instance, Database, Object, SQL Statement, Events, and Blocked Statement.
  By Instance:
  Displays a sortable list by Instance, Events, and Blocked Statements.
• Click the arrow [>] to the left of the row to display Blocker information further by Blocker ID, Database, Object, SQL Statement, Events, and Blocked Statement.
  By Database:
  Displays a sortable list by Database, Events, and Blocked Statements.
• Click the arrow [>] to the left of the row to display Blocker information further by Instance, Object, SQL Statement, Events, and Blocked Statement.
  By Object:
  Displays a sortable list by Database, Events, and Blocked Statements.
• Click the arrow [>] to the left of the row to display Blocker information further by Blocker ID, Instance, Database, Statement, Events, and Blocked Statement.
  By SQL Statement:
  Displays a sortable list by SQL Statement, Events, and Blocked Statements.
• Click the arrow [>] to the left of the row to display Blocker information further by Blocker ID, Instance, Database, Object, Events, and Blocked Statement.

To View Blocking Details:
Click the 3-DOT icon at the end of a row to view blocking details. See the Blocking – Details section for more information.