Re: cluster in lenya 2

Andreas Hartmann <[email protected]> Tue, 21 Dec 2010 16:29:16 +0100
Newsgroups gmane.comp.cms.lenya.user
Message-ID <[email protected]>
Hi Martin,

Am 21.12.10 09:39, schrieb Martin Dominguez:
> one last question... Disabling EHCache will solve this problem? Or there are
> more factors at play?

no, this will not be sufficient. Changes to the Lenya core code will be 
necessary.

-- Andreas


>
> I know that Lenya performance will be much lower...
>
> Thanks again.
>
>
> Andreas Hartmann wrote:
>>
>> 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
>>
>>
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>


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