[Freeipa-devel] "Commit comments log" functionality in IPA

[Rich Megginson]

John Dennis wrote:
> LDAP is not the right tool/technology for storing change log 
> information. Directories are optimized for particular uses, this is 
> not one of them. There is a reason why directories coexist with 
> databases, they solve different problems.
The directory is already used for storing "change log" information.  It 
can be configured to record every single operation, along with a 
globally unique identifier for that operation, the timestamp, and the 
identity who made that change.  Replication in essence just replays this 
"change log".  Maybe I am misunderstanding what you mean by "change log" 
- could you define what you mean by that term?
> Changelog entries of the type you envision are not bound to a single 
> object in the directory, rather they are a logical unit of work which 
> may affect multiple directory entries. Which entries in the directory 
> are you going to tag with the comment?
That is a big problem for DS.  We have no way to create a transaction 
that spans several operations/entries.  There is an internet draft for 
LDAP transactions, and the IBM Tivoli DS supports them.

I'm not sure how the DS could know which operations to group - the user 
would necessarily have to provide a "transaction ID" for the change set 
either explicity (as a separate attribute) or implicitly (if we 
supported transactions).
>
> This is really a problem which needs to be solved at a different level 
> and a different place. It is closely related to an audit problem. The 
> change needs to be given a transaction id which encapsulates the 
> various component changes and binds it with a comment and other meta 
> data (e.g. user id, timestamp, etc.). This is then logged somewhere 
> (but not in the directory). Audit analysis should be able to correlate 
> the changelog transaction with other auditable events (e.g. directory 
> audit logs).
The directory server already logs the raw data - we just need some way 
to collect it and group it.
>
> For now I would suggest the log destination be a file and to 
> accommodate structured information it should be written in XML.
The changelog db is easily convertible to LDIF - the DS audit log is in 
LDIF - LDIF is convertible to XML (we already have ldif2dsml tools).
> This might be a reasonable feature for v2, anything beyond that should 
> be postponed. Just this limited functionality (write the changelog in 
> xml) would meet a lot of needs, get current v2 users used to providing 
> changelog information, provides a reasonable way to view the 
> changelog, and we get all this for not a lot of work (a heck of a lot 
> less work than the other ideas).
>