[Zope] more info about BTree

[Toby Dickenson]

On Mon, 28 Jan 2002 07:48:49 -0500, Jens Vagelpohl <jens@zope.com>
wrote:

>a configuration with windoze, mySQL and zope on 64 MB of ram is, in my=20
>opinion, ridiculously underpowered for any application, let alone a=20
>server-style application such as zope.

Have you tried zope on such a machine? I assume not.

Im not familar with mySQL, but the Zope bits should run just fine on
such a machine as long as you do not want to serve many users. A
"Desktop Zope" is quite reasonable on a 32MB windows 9x machine.

One tip: you may want to change zope's startup command line to include
a "-t 1" or "-t 2". The default, if you dont specify it, is equivalent
to "-t 4" and that uses four times the memory than "-t 1". The
disadvantage is reduced concurrency, which is probably not problem on
your machine.

>> I just downloaded BTree and tried working with it as I was told btree
>> could handle large no. of objects of similar structure with ease. I
>> filled in 15,000 dtml methods and the zope almost stopped =
responding...
>> May be my test server ( a pc running win 98, my-sql and zope on 64mb
>> ram ) was not good enough. I want to know more about BTree.

I assume you mean BTreeFolder. If you are using raw BTrees then there
is more scope for a programming error.

My guess is that you are adding all of these objects in one
transaction. (that is, in one http request). This is a problem because
Zope only removes objects from memory between transactions. I suggest
adding 1, 10 or 100 objects per transaction.

I hope this helps.

Toby Dickenson
tdickenson@geminidataloggers.com