Blocked Process Report: monitorLoop

Michael Swart explains what the “monitorLoop” attribute is on the blocked process report:

You won’t find too much explanation about that field in the official documentation but I believe I know what it means.

The blocked process report is closely tied to deadlock detection and it’s generated by the same process as the deadlock monitor. If you remember, the deadlock monitor runs frequently looking for deadlocks (which are just blocking chains in a circle). It runs every couple seconds when there are no deadlocks, and if it detects any, it runs a bit more frequently. Each time it runs it’s called a monitor loop. The monitorLoop is just a number that starts at zero when the server restarts and increments by one each time the monitor runs.

Read on for more details.

Related Posts

OLTP-Friendly Database Deployments

Michael Swart looks at one of the biggest problems when trying to do a zero-downtime deployment to an OLTP system: There are two main kinds of SQL queries. SELECT/INSERT/UPDATE/DELETE statements are examples of Data Manipulation Language (DML). CREATE/ALTER/DROP statements are examples of Data Definition Language (DDL). With schema changes – DDL – we have the […]

Read More

What Update Locks Do

Guy Glantser explains the process around updating data in SQL Server, particularly the benefit of having update locks: In order to update a row, SQL Server first needs to find that row, and only then it can perform the update. So every UPDATE operation is actually split into two phases – first read, and then […]

Read More

Categories

February 2017
MTWTFSS
« Jan Mar »
 12345
6789101112
13141516171819
20212223242526
2728