Attachment Size Limits
Asked by IT KnowledgeSystemsManagement:

Recently we have had one of our users request a limit increase for attachements in our confluence install. Has anyone experienced any issues with attachments in the 300MB and up range?

Is there an upper limit before DB storage becomes a problem?


Answers:
author: Jim Birch
body: I'd be **careful** about allowing attachments bigger than 10 Mb - it imposes discipline on users. To mitigate this we have we temporarly increase the limit *on request* for valid purposes.

Where have had a few cases of really big files - eg, 200 Mb training videos - we use the tomcat sever rather than Confluence to handle them.

Create a directory under the the Confluence app directory eg **\\confluence-3.4.9-std\\confluence\\bigfiles** Grant access to selected users to put the big files files there.

The files can them be linked via a confluence url, eg, **http://confluence.ourcompany.local/bigfiles/x.txt** or via a link on a Confluence page like **//bigfiles/x.txt** (in square brackets)

If you want to go one stop further you can use a directory outside the Confluence structure, see eg <http://gandhim.wordpress.com/2008/01/31/tomcat-55-virtual-directory/> We didn't bother with this because we add the big files ourselves and we trust ourselves. Content type controls are also possible to prevent server side executables from being added.

Pros

* Fast serve. Files are not triple served, SQL -\> Confluence -\> tomcat
* Fast upload via file system.
* Not stored in SQL Server
* Not indexed
* Can embed like external content

Cons

* Outside the "system"
* Not indexed, or searchable
* Need to move directory on upgrade
* No automatic pickup of files in the editor
* Security risk if you don't trust the content/provider since server side executables could be added.
* Upload complexity. If occasional could be an admin task.
* Difficult to do external upload


author: David at David Simpson Apps
body: I'm sure you've got your reasons, but I can't help thinking that this is just **a bad idea**. If this is a popular download it will have a negative effect on the performance.

Uploading a 300MB+ file through a web browser is unlikely to be fruitful. Admittedly you could try using WebDAV, which will work but that doesn't have the greatest user experience.

comments: author: David at David Simpson Apps
body: Also the default setting is just 10MB -- somewhat meagre in comparison to your requirements.


author: IT KnowledgeSystemsManagement
body: Thanks for the followup David.

Our requirement is from our userbase and seen as a ligit business reason.


author: m@
body: There may be an upper limit imposed by your database but its going to be so big that I doubt its going to be a problem.

Confluence is not going to handle large attachments perfectly, so you may need to tweek settings to disable indexing (for example) for these kinds of files.

To increase the attachments size you go to the general configuration screen in your administration section and edit the "Attachment Maximum Size" property.


author: Colin Goudie
body: By default the attachment data is stored on the filesystem. However indexing and accessing this would of course be affected. I do recall though that Sony were storing Blue Ray images in theirs. Not sure how true that is


Tags: attachment