[protege-discussion] Enable Journaling in Project Options

[Tania Tudorache]

Jonathan,

Sorry I did not read this message before answering your more recent post.

I see what the problem is. Indeed the annotation ontology becomes very 
large even with a moderate number of changes. I am not sure whether you 
saw the new feature of the Changes Tab, that allows you to delete all 
change instances from a menu [1].

I think the solution would be to store the changes ontology in a 
database, which I did not have time to implement yet, although I have 
promised this a longer time ago :) I was testing some code that would 
allow you to store the annotation ontology in a database. I still want 
to test, whether this fix will have an impact on performance. If 
everything goes fine, the fix will be available in the next beta build. 
I can also send you before that a jar that you can test.

The journal is a very detailed log file that is not very easy to 
analyze, because it is at very low level. Some operations that a user 
sees as atomic, might be recorded as several smaller changes. The size 
of the journal file grows pretty quickly. Users may experience a slow 
down at write operations, although this may not be noticeable for normal 
UI operation.

Tania

[1]: http://protegewiki.stanford.edu/index.php/Changes_Tab


Jonathan Carter wrote:
>
> Hi everyone,
>
> I've been trying to understand more about what the 'Enable Journaling' 
> option in Project Configuration can do for me. I have found some 
> documentation of PromptTab that says that Prompt can use the 
> Journaling to show who has done what in a Project during a diff.
>
> As some background to why I am looking at this - maybe it won't help 
> me - I am trying to find a way of controlling the amount of change 
> information that is being created in my Project.
>
> Currently, I am using 'Track Changes' and Collaborative Protege 
> running on a server with a handful (around 3) concurrent users. The 
> project is using a MySQL database as the framestore and this is 
> working well. However, the annotations file for my project (that is 
> tracking all the detailed change history) is just that - a file. The 
> problem I am having is that I am getting a very large number changes 
> in my project and so in periods of high useage (the team using the 
> project all day making changes to the model, for example) my 
> annotations_ file can reach 4-5MB in a matter of a couple of days. 
> Because this is a file, it must be periodically saved and the contents 
> held in memory, so everything slows down as the file gets big. If I 
> let it get too big, I can get out of memory exceptions on the server, 
> which can really cause problems.
>
> I may be seeing a slightly 'amplified' number of changes going into 
> the model because I am making extensive use of a slot widget that I 
> wrote that automatically names String slots based on patterns that 
> include the Browser text of other slots in an instance but the problem 
> would bite me at some point either way. Currently, I am regularly 
> archiving off the annotations project, purging the timestamps and 
> change instances and then continuing with a "purged" change history.
>
> Ideally, if the annotations file could be stored in the database 
> instead of a file then the problem is more easily managed (and becomes 
> purely about storage).
>
> So, I'm wondering whether enabling journaling either on project would 
> give me the change log (so I can see who's made what change) or on the 
> annotations file would improve the way that that is persisted.
>
> Any information about what the purpose of the 'Enable Journaling' 
> option is and how it affects project storage would be gratefully 
> received. As would any suggestions/experience of managing the 
> annotations file when using the very useful Collaborative Protege plugin.
>
> Thanks very much for your help
>
> Jonathan
>
> __________________________________________
> Jonathan Carter - Head of Technical Architecture
> Enterprise Architecture Solutions Ltd
>
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