[Date Prev][Date Next]
Re: OpenLDAP 2.5
> We should also walk thru the Software Enhancement requests and
> decide which to accept and which to reject. Currently there are 37
Here's a few things we talked about on IRC:
* Re-design and re-implemenation of the C LDAP (and LBER) API.
** No global state; everything in app or connection handles. No
exceptions, no mercy!
** Use function pointers to allow override of
*** Memory allocation
*** Non-reentrant functions
*** Have sane internal defaults as well as defaults for nspr, apr,
** Better defaults! (v3 etc)
** Simple function alternatives for simple apps
** Use structures instead of many arguments.
* Overhaul Debug():
** Clean up multi-arg issues
** Revise (create) log formatting guidelines
** Better macros to normalize function trace enter/leave
** Support adding an optional high-res timestamp
* Revised memory allocation:
** Common memory allocator interface with explicit scoping/extent tags
** Consider built-in substitutes for malloc with better performance
** Possible interactions/conflicts/advantages of back-mdb integration
* Back-MDB concerns:
** Schema info in non-mmap ram pointed to from an mmap()d database?
(no, and you mentioned this, but we'll need to re-arrange things,
as discussed on IRC) Per DB schemas?
* Ensure fork() can based safely in more places - Essential for a
fully operational slapo-(shell, perl, lua, python, etc)
* With API cleanups here and there, start supporting more languages
* liblforth for dynamic syntax extensions and other features.
(back-forth just sounds like an apr1 proposal...)
* Entry cache overhaul
** The right fix for this is MDB instead, but...
** Would be very nice to specify limits in terms of memory size rather
than object count. Yes, this is hard. - Allocation of entry blocks
into usage pools with generational mark/sweep collections?
> > 2. If support for slapd.conf is completely dropped would it also
> > be possible to implement a more client-friendly back-config schema
> > which does not have to be backward compatible to slapd.conf?
> Describe what would be more client-friendly.
* Make database suffixes be the RDN for database configuration -
Use unique RDNs with inherently ordered characteristics where-ever
possible Obviously not for ACLs, but many other things are fixable
* Similarly, Drop the concept of backend ordering entirely and move
slapo-glue into more generic VFS-like support of the DIT
* Databases should only store one suffix. No, I'm not sure how that
should integrate with people putting "" in a database yet. Need to
figure that out.
* slapmodify - too useful to not implement now that we have a
configdb. Bonus points if it (and slapadd) can be made safe to use
with a running directory in all cases. (Perhaps a cache-
invalidation-hint unix domain socket?)
* Full two-phase commit support at all layers, including
read-transaction support. Back-MDB should make this feasible, and
it offers lots of nice data reliability guaranties.
** Use multiple dbroots in MDB to track read/write transactions as
** Commited data in MDB is effectively read-only. Read transactions
just hold their relevant generational root open.
** Write transactions hold open a parent-generation and maintain a log
of updates as well as a local difference-tree holding just modified
branch/leaf nodes. On prepare, this is reconciled with the new
master-commited root and entered into the mmap zone. (or rejected)
On commit, that new root is promoted to master-commited root.
** Roots disappear when no one is watching them anymore. If all roots
and temp-roots are known, we can easily remove internal nodes and
leaves at the same time, so this is much simpler than full garbage
** Root cleanup can be done asynchronously with respect to the
triggering reads or writes, potentially in another thread.
** This method is equivalent to, and replaces a journal file.
Commited MDB tree pages could be mprotect()ed if desirable.