My very *personal* impression is that Slide could need improvements for clustering. However, a redundancy solution might look like having two Slide instances both accessing the same RDBMS (clustering will not work with the default file store). This RDBMS might be a clusterd one as well, what ever you want.

As there is (currently) no notification mechanism (this might be implemented with the event stuff Daniel added) between Slide instances and global caching might return outdated values I added this caching mode that only caches inside of transactions.

Oliver

James Mason wrote:

Oliver,
Can you elaborate on this a bit? It's something I'm *very* interested
in. I'm slowly integrating Slide into a Portal/CMS solution that
failover/redundancy at every level and Slide is sticking out a bit like
a sore thumb :).

-James


[EMAIL PROTECTED] 7/8/2004 6:25:08 AM >>>

Hi Jamie!

In the upcoming 2.1 release it will be possible to switch off caching
by
configuration. It will also be possible to use a mode that allows for
intra-transaction caching which is much faster, but enables
clustering.

Oliver

Mortimore, Jamie [IT] wrote:

Slightly off topic but... I'm going to try using cjdbc

(http://forge.objectweb.org/projects/c-jdbc) to connect a JDBCStore to two databases in order to create a fault tolerant webdav service. There will also be two slide servers:

--------      --------
| slide  |    | slide  |
| server |    | server |
| 1      |    | 2      |
--------      --------
   |             |
--------      --------
| CJDBC  |----| CJDBC  |
--------\    /--------
   |     \  /    |
   |      \/     |
--------  /\  --------
| DB1    |/  \| DB2    |
--------      --------

If one slide server or one database becomes unavailable the system

will still be operational. In order for this to work neither slide server should cache (if 1 updates the db and 2 has a cached version, 2 will not see the update).

I had a quick look at the src for slide 2.0 and it looks like caching

is not configurable (cacheResults returns true in org/apache/slide/common/AbstractServiceBase.java). So, just to confirm, in order to switch caching off I will have to extend JDBCStore and overide cacheResults to return false?

In addition I would be interested if anyone has any feedback on the

above architecture (eg will it work?). It does not have to be super responsive but must be fault tolerant because, if all goes well, many other business critical systems will be relying on the system availability.

Regards,

Jamie.

-----Original Message-----
From: Andreas Probst [mailto:[EMAIL PROTECTED] Sent: 08 July 2004 06:35
To: Slide Developers Mailing List
Subject: Re: StandardStore, AbstractStore, caching



Hi Oliver,

thank you for the quick response. Sorry, but I copied it from cvs head. It's not fixed there. Below are the ID tags.



/home/cvspublic/jakarta-slide/src/share/org/apache/slide/store/AbstractStore.java,v 1.42 2004/06/23 09:13:42 ozeigermann Exp $

/home/cvspublic/jakarta-slide/src/share/org/apache/slide/store/StandardStore.java,v
1.22 2004/02/11 11:30:18 ozeigermann Exp $

Regards,

Andreas

On 7 Jul 2004 at 23:54, Oliver Zeigermann wrote:



Andreas Probst wrote:


for the project I'm working in I need to change the caching behaviour of Slide. Looking at StandardStore, which does the caching, I wonder:

If caching is disabled, read calls are forwarded to super (AbstractStore), which then calls the actual Store implementation.

If caching is enabled but the object to read is not in the cache, the calls are not forwarded to super but to the actual Store implementation, e.g. DescriptorsStore.

Why is it done this way? Is it just style?
When super is called, the Stores are listed in a transaction...

I guess you are referring to 2.0, right? I have done this stuff and

as


far as I remember, it was just non sense and I fixed it in the

current


CVS head.

Oliver





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