Gentoo Archives: gentoo-dev

From: Eric Sammer <eric@××××××××××××.com>
To: Patrick Kursawe <phosphan@g.o>
Cc: gentoo-dev@g.o
Subject: Re: [gentoo-dev] Directory services (was Re: [gentoo-dev] maybe it is time to put portage queries into a database.)
Date: Fri, 27 Jun 2003 15:39:35
In Reply to: Re: [gentoo-dev] Directory services (was Re: [gentoo-dev] maybe it is time to put portage queries into a database.) by Patrick Kursawe
1 Patrick Kursawe wrote:
2 > I wonder how LDAP should have a better performance than rsync?
3 > Are there implementations that support compression while transmitting
4 > only the delta between entries?
6 Directory services work very differently than rsync. I do believe that
7 compression is supported (specifically in openldap) between servers
8 during replication. The way ldap works (quick and dirty) is that when a
9 change is made to the master, the change is written to a log file.
10 Another daemon (again, specific implementation of openldap) is
11 constantly reading the transaction log and sends the updates down the
12 line to slaves. In theory, it is similar to the way DNS works
13 (propagation and referals). If you decide that replication is
14 undesirable, referrals allow you to tell your *local* ldap server to
15 resend the request to a designated parent (which then can resend and
16 resend and so on) - this is much like DNS. What's cool is that a stream
17 of single transactions would be consistently flowing through the
18 (hypotetical) network of Gentoo master ldap servers which could be
19 accessed by region by users using portage. The performance would
20 probably be better because (AFAIK) less overall traffic should be
21 required and ldap has provisions for defering load (replication and
22 referrals).
24 > I have next to no experience with directory services, so could you
25 > please outline a bit further why you think this is better than rsync
26 > or a database?
28 Further reading might describe it better than I can. Check out
29 for the details.
31 > Yours sceptically,
33 Hehhehe... if everyone just jumped at it, things would get messy fast. ;)
35 --
36 Eric Sammer
37 eric@××××××××××××.com
41 --
42 gentoo-dev@g.o mailing list