topic Re: storage engine and checksum of content in Alfresco Archive

storage engine and checksum of content

fluca1978 — Thu, 07 Apr 2011 16:11:15 GMT

Hi all,I'm just curious if Alfresco has already a way to guarantee that what you put into the repository is the same thing you can get out, even in the presence of disk corruption. I mean, is there an hashing/checksum on the content placed into the repository?Thanks.

Re: storage engine and checksum of content

llemtt — Tue, 12 Jul 2011 14:43:41 GMT

Good question

I am wondering that too!

Actually I am planning a script to calculate crc and store into metadata, later on I can use it to check content integrity again.

Re: storage engine and checksum of content

mrogers — Tue, 12 Jul 2011 14:54:29 GMT

The content size is already there, could you use size instead?

Re: storage engine and checksum of content

fluca1978 — Mon, 25 Jul 2011 10:48:10 GMT

It is not clear what you mean, but using the size attribute to do a consistency check sounds silly to me.

Re: storage engine and checksum of content

andy — Wed, 27 Jul 2011 09:30:11 GMT

Hi

There is no way to do this.
It sounds like a handy enhencement to me.
I suggest you raise an enhancement.

Andy

Re: storage engine and checksum of content

cpaul — Tue, 22 Nov 2011 02:06:58 GMT

Hi all,

I just wrote a blog post that walks through adding a custom aspect to generate checksums for Alfresco content here:

http://www.productivist.com/2011/11/21/generate-checksums-for-alfresco-content/

Feel free to check it out and let me know if you have thoughts or questions.

Chris

Re: storage engine and checksum of content

cszamudio — Wed, 20 Jun 2012 16:38:43 GMT

Thanks for this thread and the reference to the blog entry.

I plan to use this approach to test whether a user is uploading a duplicate of content already on a Site.

To me, a content checksum seems like a pretty fundamental requirement for a Content Management System. The Aspects solution is a good workaround.

Carlos

Re: storage engine and checksum of content

everbehere — Thu, 20 Feb 2014 19:35:21 GMT

I want to use the facility of checksums and reject the documents which have the same content. But I am not able to go to the right path. It will be quite helpful if you or someone can provide me the solution.

Re: storage engine and checksum of content

docderivative — Fri, 07 Mar 2014 12:55:34 GMT

We actually have a similar but different requirement. We have many cases where the same document is uploaded many times (really an artifact of a poor document object model in the business process) and we only store the same document once and use associations to link the content with the meta data. The duplicate detection is based on a MD5 hint and then a byte by byte comparison to be sure.

Would be quite nice to have a storage layer that only stored the same content once and used reference counting but obviously this has a hit to complexity and performance.

Re: storage engine and checksum of content

ozgeayaz — Fri, 21 Mar 2014 15:01:49 GMT

Hi All,

I use Alfresco-4.2.e.I wonder how to alfresco keep permission document.Does a json, a document or database included ?

Re: storage engine and checksum of content

midoscofield — Fri, 08 May 2015 10:18:42 GMT

the link is updated:
http://blog.productivist.com/generate-checksums-for-alfresco-content/