Re: cluster in lenya 2

Hi Martin,

Am 15.12.10 12:56, schrieb Martin Dominguez:
> We have a cluster with 2 nodes with publication contents in a directory
> shared by NFS.
>
> Users change contents in master node, and here is my problem, if something
> in sitemap (delete a document, publish a document..) changes then I have to
> restart lenya in slave node. If I don't restart lenya service slave node
> shows a famous error: "Latest revision loaded is not true".
>
> It seems that Lenya not recognize changes made by another instance in their
> contents. But, this problem didn't exits in Lenya 1.2...

this is true. In Lenya 1.2, all files including the sitetree file were 
read (or at least their validity was checked) for each response. In 
Lenya 2 we introduced some optimizations regarding memory usage and 
performance. This includes a shared in-memory sitetree and a meta data 
cache. These objects are not reloaded for each request, so basically 
Lenya 2 is not clusterable yet.

The good news is that the European Patent Office has commissioned the 
implementation of the clustering ability, with some restrictions:

* Only the live area will be clusterable.
* The live area has to be read-only (i.e. no user generated content).
* Access control data will not be reloaded (i.e. if you change live area 
policies you have to restart the servlet container).

The EPO will kindly donate the resulting code to the ASF. This will 
probably happen during January or February.

HTH,

-- Andreas


-- 
Andreas Hartmann, CTO
BeCompany GmbH
http://www.becompany.ch
Tel.: +41 (0) 43 818 57 01