Learn More





DNN Community Blog

The Community Blog is a personal opinion of community members and by no means the official standpoint of DNN Corp or DNN Platform. This is a place to express personal thoughts about DNNPlatform, the community and its ecosystem. Do you have useful information that you would like to share with the DNN Community in a featured article or blog? If so, please contact .

The use of the Community Blog is covered by our Community Blog Guidelines - please read before commenting or posting.

DotNetNuke Miscellany #1 – PurgeCache Scheduled Task

This article is cross-posted from my personal blog.

Welcome to a new series of short articles on miscellaneous tips, tricks and information for DotNetNuke Users and Developers.

Purge Cache Scheduled Task

Over the last few days I have been trying to solve an issue with the Scheduler in version 4.9.  There are a number of threads that discuss the issue in the DotNetNuke Forums.  One of the threads was concerned that the Purge Cache Scheduled Task wasn’t running properly, as the cache items were not being removed from the cache when this task completed.

While there was a “real” issue with the File Based Caching provider (which has been fixed), the user did not completely understand what the Purge Cache task actually does.

Of course, part of the confusion arises from the name given to the task, which could be read to mean that the task removes all the current items from the cache.  However, this is not what this task is designed to accomplish.

Both the File Based Caching provider and the Broadcast Polling Caching provider use mechanisms that can be used to synchronize the ASP.NET cache between servers in a web-farm. 

In the File Based Caching Provider, for example, file stubs are saved to the Portals/_default/Cache folder which are used to create a file dependency on the cached items.  When the cache expires on one serer, the file is modified which causes the other servers to expire their copy of the cached item. 

Unless the cached item is explicitly removed (rather than scavenged) this file stub is left in the Cache folder.  Over time the number of file stubs will grow, so the Purge Cache task is used to clean up these file stubs.

The Purge Cache task does NOT clear the ASP.NET Cache (there is a button in Host Settings that does that).  Also it is important to note that unless you are using a Web Farm you do not need to use this task at all, as the file stubs are only created in Web Farm scenarios.

I hope this helps.  If you have any ideas for this series of tips, let me know.


Comment Form

Only registered users may post comments.


2sic Daniel Mettler (124)
Aderson Oliveira (15)
Alec Whittington (11)
Alex Shirley (10)
Andrew Nurse (30)
Anthony Glenwright (5)
Antonio Chagoury (28)
Ash Prasad (21)
Ben Schmidt (1)
Benjamin Hermann (25)
Benoit Sarton (9)
Beth Firebaugh (12)
Bill Walker (36)
Bob Kruger (5)
Brian Dukes (2)
Brice Snow (1)
Bruce Chapman (20)
Bryan Andrews (1)
cathal connolly (55)
Charles Nurse (163)
Chris Hammond (203)
Chris Paterra (55)
Clinton Patterson (28)
Cuong Dang (21)
Daniel Bartholomew (2)
Dave Buckner (2)
David Poindexter (3)
David Rodriguez (2)
Doug Howell (11)
Erik van Ballegoij (30)
Ernst Peter Tamminga (74)
Geoff Barlow (6)
Gifford Watkins (3)
Gilles Le Pigocher (3)
Ian Robinson (7)
Israel Martinez (17)
Jan Blomquist (2)
Jan Jonas (3)
Jaspreet Bhatia (1)
Jenni Merrifield (6)
Joe Brinkman (269)
John Mitchell (1)
Jon Henning (14)
Jonathan Sheely (4)
Jordan Coopersmith (1)
Joseph Craig (2)
Kan Ma (1)
Keivan Beigi (3)
Ken Grierson (10)
Kevin Schreiner (6)
Leigh Pointer (31)
Lorraine Young (60)
Malik Khan (1)
Matthias Schlomann (15)
Mauricio Márquez (5)
Michael Doxsey (7)
Michael Tobisch (3)
Michael Washington (202)
Mike Horton (19)
Mitchel Sellers (28)
Nathan Rover (3)
Navin V Nagiah (14)
Néstor Sánchez (31)
Nik Kalyani (14)
Peter Donker (52)
Philip Beadle (135)
Philipp Becker (4)
Richard Dumas (22)
Robert J Collins (5)
Roger Selwyn (8)
Ruben Lopez (1)
Ryan Martinez (1)
Salar Golestanian (4)
Sanjay Mehrotra (9)
Scott McCulloch (1)
Scott S (11)
Scott Wilkinson (3)
Scott Willhite (97)
Sebastian Leupold (80)
Shaun Walker (237)
Shawn Mehaffie (17)
Stefan Cullmann (12)
Stefan Kamphuis (12)
Steve Fabian (31)
Timo Breumelhof (24)
Tony Henrich (3)
Torsten Weggen (2)
Vicenç Masanas (27)
Vincent Nguyen (3)
Vitaly Kozadayev (6)
Will Morgenweck (37)
Will Strohl (163)
William Severance (5)
Try Evoq
For Free
Start Free Trial
a Demo
See Evoq Live
Need More Information?