[TransWarp] Transactionality and enterprise politics (was Re: Tips on using model, storage, config, and naming)
Roché Compaan
roche at upfrontsystems.co.za
Mon Dec 30 08:32:33 EST 2002
* Phillip J. Eby <pje at telecommunity.com> [2002-12-30 17:45]:
> >I was caught by surprise with your comments on MySQL and am now
> >seriously re-evaluating :-) I don't for one minute think MySQL is all
> >there is to databases - I am *very* aware of its limitations. At the
> >moment it provides me with a reasonably stable and affordable database
> >on Linux and Windows whereas Postgres needs to run in a Cygwin
> >environment on Windows and I don't now how this will affect its
> >performance. I also thought that MySQL's lack of referential integrity
> >and transactions is ok as long as their is a layer or middleware above
> >it that takes care of it?
>
> But how much does it cost you to create that middleware? And more to the
> point, what does it gain you? If you chose MySQL for speed, adding a
> middleware layer to do that stuff is just going to slow it down. Why not
> just use a reasonably fast DB in the first place?
>
> As for Cygwin performance, the main issue to watch out for is memory
> consumption of anything that does 'fork()'. Windows doesn't do fork, so
> Cygwin emulates it by copying the entire app's memory contents at fork
> time. The next thing to watch out for would be filesystem performance.
>
> But I do have a question for you... do you need to run a multi-user server
> from a Windows machine?
Multi-user server: yes
>From a Windows machine: not when I have a choice or can influence the
decision. Use of Windows is still policy in some of our corporate
clients and they don't budge easily. We normally try to give a turnkey
solution ie. server + linux + our product. We have one product in use by
a couple of corporates but there is only one table in this product that
gets hit really hard and it doesn't have to handle any simultaneous
edits - it only has to insert batches really fast.
> >Before I started using MySQL, I used
> >Interbase/Firebird but it was really unstable on linux. So, what are my
> >options?
>
> To be honest, it has been at least 5 years since I seriously considered a
> Windows machine a suitable basis for any kind of multi-user application
> server, so the cross platform issue hit a blind spot for me here. My
> emphasis on Windows support in PEAK has been primarily intended for client
> applications, and I didn't even know that MySQL *ran* on Windows.
As I explained it's not always my choice.
> >What implementation of LDAP are you using? I ask because OpenLDAP does not
> >currently support transactions?
>
> We don't perform transactional operations against LDAP; we use it as a
> directory service only, so atomic operations suffice. We do in fact use
> OpenLDAP, although we have a Netscape server as a central repository for
> pushing to OpenLDAP replicas on each machine that needs access to the
> directory.
But an EntityDM wants to join a transaction in __getitem__ so how will
they work with a LDAPConnection?
--
Roché Compaan
Upfront Systems http://www.upfrontsystems.co.za
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