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Posted to slide-user@jakarta.apache.org by Darren Hartford <dh...@ghsinc.com> on 2006/07/20 16:28:57 UTC
Domain.xml - what is 'sequential-mode'?
In domain.xml, configuration node, what is this configuration option
used/useful for?
<!-- Can be "off", "fine-grain", "write" and "full" -->
<parameter name="sequential-mode">fine-grain</parameter>
Specifically in regards to optimizing for search/read performance while
still maintaining write-integrity.
Thanks,
-D
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Re: Questions on Sequential-modes and the next release?
Posted by Oliver Zeigermann <ol...@gmail.com>.
2006/7/22, Oliver Zeigermann <ol...@gmail.com>:
> > Does fine-grained work better?
>
> Fine grain locking only locks those folders that are actually
> concerned by an action. This may lead to some form of - very hard to
> explain - distributed deadlock, though. Depending on your database and
> then again isolation level.
One addition: Theoretically, fine grain locking should work fine when
all locking is done in the application, i.e. Slide. This can either be
achieved by using an optimistic, non-blocking isolation strategy (like
serializable with Oracle) or a very low one (read uncommitted). I
haven't tried this practically, though, but might be worth an
experiment.
Cheers
Oliver
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Re: Questions on Sequential-modes and the next release?
Posted by Oliver Zeigermann <ol...@gmail.com>.
Hey, Eirikur
2006/7/21, Eirikur Hrafnsson <ei...@idega.is>:
> what problems could I run into if I use sequential-mode = OFF ?
This completely disables Slide's internal locking. It might cause some
weired concurrency errors as Slide's internal cache only supports an
isolation level similar to read committed. If you set your databases
isolation level to read committed as well this should be more
consistent. However, this isolation level might not be appropritate to
what you do.
Another secure solution would be to switch off caching and set
database isolation to serializable. The performance penalty is
disastrous, though.
> We're running webapplications on Slide with various databases and today we
> are using "WRITE" mode but I find it bothersome that a whole folder is
> locked for read access when a long write is happening to one of its files.
>
> Does fine-grained work better?
Fine grain locking only locks those folders that are actually
concerned by an action. This may lead to some form of - very hard to
explain - distributed deadlock, though. Depending on your database and
then again isolation level.
An alternative is the option to retry upon conflict. This comes at a
general performance penalty, but may be a good option.
More details at
http://wiki.apache.org/jakarta-slide/ConcurrencyIssues
> For example a webapp we created automatically gets RSS feeds and stores them
> in Slide every 20 minutes. The frontpage of the webapp then tries to read
> these files via an Ajax RSS reader and has to wait until the writes are
> finished. I would much rather (if versions are enabled) that while the PUT
> is going on the GET would get the last version available but otherwise wait
> until the PUT is done and only that resource gets locked up for the moment.
> Is that possible today?
Might work if you upload to a diffrent file name and later move it to
the desired one. Move generally should be be faster than put.
> And the last question...when will the next stable version of Slide be
> released?
Don't ask me. I have no idea.
Cheers
Oliver
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Questions on Sequential-modes and the next release?
Posted by Eirikur Hrafnsson <ei...@idega.is>.
Hey Oliver,
what problems could I run into if I use sequential-mode = OFF ?
We're running webapplications on Slide with various databases and
today we are using "WRITE" mode but I find it bothersome that a whole
folder is locked for read access when a long write is happening to
one of its files.
Does fine-grained work better?
For example a webapp we created automatically gets RSS feeds and
stores them in Slide every 20 minutes. The frontpage of the webapp
then tries to read these files via an Ajax RSS reader and has to wait
until the writes are finished. I would much rather (if versions are
enabled) that while the PUT is going on the GET would get the last
version available but otherwise wait until the PUT is done and only
that resource gets locked up for the moment. Is that possible today?
And the last question...when will the next stable version of Slide be
released?
best regards
Eiki, idega.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Eirikur S. Hrafnsson
Chief Software Engineer
eiki@idega.is
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Idega hf. ı Engjavegi 6 ı 104 Reykjavík ı Iceland
Tel. +354 554 7557 ı Fax +354 885 7557
http://www.idega.com ı idega@idega.com
On 20.7.2006, at 20:35, Oliver Zeigermann wrote:
> This should be explained here:
>
> http://wiki.apache.org/jakarta-slide/ConcurrencyIssues
>
> Oliver
>
> 2006/7/20, Darren Hartford <dh...@ghsinc.com>:
>> In domain.xml, configuration node, what is this configuration option
>> used/useful for?
>>
>> <!-- Can be "off", "fine-grain", "write" and "full" -->
>> <parameter name="sequential-mode">fine-grain</parameter>
>>
>> Specifically in regards to optimizing for search/read performance
>> while
>> still maintaining write-integrity.
>>
>> Thanks,
>> -D
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: slide-user-unsubscribe@jakarta.apache.org
>> For additional commands, e-mail: slide-user-help@jakarta.apache.org
>>
>>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: slide-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: slide-user-help@jakarta.apache.org
>
Re: Domain.xml - what is 'sequential-mode'?
Posted by Oliver Zeigermann <ol...@gmail.com>.
This should be explained here:
http://wiki.apache.org/jakarta-slide/ConcurrencyIssues
Oliver
2006/7/20, Darren Hartford <dh...@ghsinc.com>:
> In domain.xml, configuration node, what is this configuration option
> used/useful for?
>
> <!-- Can be "off", "fine-grain", "write" and "full" -->
> <parameter name="sequential-mode">fine-grain</parameter>
>
> Specifically in regards to optimizing for search/read performance while
> still maintaining write-integrity.
>
> Thanks,
> -D
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: slide-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: slide-user-help@jakarta.apache.org
>
>
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