maximum attachments (number and size)

Question

Hi, we are going to use confluence as a storage for many of our files. But before we will outsource our storage servers to confluence I want to know if you have any experience of possible limitations for this.

Will a large number of attachments slow confluence down? (50000+) Is there any limitation in the number of attachments?

Size of attachment storage? We want to bind an external storage server to the attachment storage of confluence (~5TB), will confluence handle this?

James Tran3 · Answer

Riccardo, I've been looking online for a way to mount a NAS as attachment storage.  Would you mind providing some details or links on how I can get this setup? thanks.

Riccardo Salzer1 · Answer

Hi John,

We did it now :) .
We have already changed the maximum file size to 50MB for now and we mounted a storage server as attachment storage with 6,4TB. After a restart confluence seems to run quietly fast and all attachments were loaded quickly. I am shy to run a reindex of all attachments but as this is not neccessary for no, it runs good :) .
thanks for your information,

Riccardo

JohnA_xb3t2l · Answer

Hi Riccardo,

By default the maximum attachment size Confluence can handle is 10MB, although you can increase this by following the instructions in this document: https://confluence.atlassian.com/display/DOC/Configuring+Attachment+Size

Currently the maximum file size that Confluence can handle is 2GB, and from the look of this bug report that is currently a hardcoded limit: https://jira.atlassian.com/browse/CONF-20912

However, the biggest problems I would expect you to experience is that if the connection to the storage isn't lightning quick then you may experience significant performance issues as a result, (not just in accessing attachments but also indexing them etc).

The other problem, and one could potentially cause even more problems than the storage location, is that the application will need to index every attachment and this could put immense strain on the instance, (even if it's only indexing the file names and not the contents), because the indexing of large attachments requires that the attachment be loaded into memory. In the case of large attachments, this can cause a temporary strain on the systems resources, and may result in indexing failing because the attachment could not be fully loaded into memory.

It is possible to set a limit for the size of attachments to be indexed, which I would strongly recommend, but I'm not sure how well Confluence will handle that many attachments in general so I would suggest testing it first to ensure that it works as expected before pushing it into production.

All the best,
 John