Forum OpenACS Q&A: Re: OpenACS clusters

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8: Re: OpenACS clusters (response to 1)
Posted by Claudio Pasolini on 03/02/11 05:03 PM
I did some simple tests and the cache flushing mechanism between the application servers works well, as long as the application calls the util_memoize_flush proc.

I'm surprised that changing a package parameter doesn't call the flushing proc: perhaps this is a feature and not a bug, but eventually this could be easily fixed.

I also played loading, retrieving and deleting attachments to my application objects, so hitting the content-repository-content-files folder, apparently without any error.

I want to thank everyone for giving their advice and sharing their experience. Should the clustering fail for any reason, I'm prepared to downgrade to a proven setup, with one DB server and one AS.

Meanwhile, thanks to some tuning on the VMWare side and 1 GB more on every AS, the cluster performance is now comparable to that of the physical development server, but at the same time gives me the perspective to be more scalable.

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9: Re: OpenACS clusters (response to 8)
Posted by Eduardo Santos on 03/02/11 05:27 PM
Hi Claudio,

I'm glad everything is working ok. The problems you can see are going to happen when the first threads die and the system tries to create them again, usually a situation you can see only in production environments.

Keep an eye on possible memory leaks and make sure you use Gustaff's patch for background delivery. This is the feature in OpenACS that makes the best performance improvement so far.

Best regards

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10: Re: OpenACS clusters (response to 9)
Posted by Maurizio Martignano on 03/11/11 12:06 PM
Dear Eduardo,
I like the part where you mention "memory leaks"...
All the mechanism described by Claudio is exactly a way of coping with the memory leaks present in web/application servers and offer anyhow to the end customers highly available systems. This is better described here:
http://www.spazioit.com/pages_en/sol_inf_en/distributed-sand-box-for-application-servers_en/
Ciao,
Maurizio