concurrency problems

Asked by Ernesto

Hi guys, I have some time observing the status of the project and have some doubts about it.

In first place, I would like to know how to deal the concurrency problems, for example, when many writers access to same file at the same time. This case I can't prove it because I have many problems with the syncronization of files (I only can upload to server, I can't download).
I'm observing the synchronization algorithm and can't see it in nowhere.

At second place and respect to download files to server, some time ago I hadn't this problems although didn't work correctly..

Thank you!

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Syncany Edit question
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Solved by:
Philipp C. Heckel
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Revision history for this message
Philipp C. Heckel (binwiederhier) said :
#1

Hallo Ernesto,

Different instances of Syncany (assuming different computer names!!) never
access the same files on the server. Each instance/computer writes its own
update file. So there are no concurrency issues here.

The only file that is written by multiple clients is the repository-* file.
But since this only happens if new shared folders are added, it is very
unlikely to be overwritten.

The "downloading files" issue only occurs when the computer name of the "new
instance" is the same as the previous one -- because syncany assumes that
you are the same guy.

Did that answer your questions?

Cheers,
Philipp

Revision history for this message
Ernesto (ernesto-cdelgado) said :
#2

Ok, but I don't understand because I can't download from server, my syncany
version is the "lp:syncany", maybe this version isn't the last.
I have saw the newsync version but I haven't found the build file and don't
know compile the Syncany.

Sorry if these questions are absurd.

2011/7/12 Philipp C. Heckel <email address hidden>

> Your question #164516 on Syncany changed:
> https://answers.launchpad.net/syncany/+question/164516
>
> Status: Open => Answered
>
> Philipp C. Heckel proposed the following answer:
> Hallo Ernesto,
>
> Different instances of Syncany (assuming different computer names!!) never
> access the same files on the server. Each instance/computer writes its own
> update file. So there are no concurrency issues here.
>
> The only file that is written by multiple clients is the repository-* file.
> But since this only happens if new shared folders are added, it is very
> unlikely to be overwritten.
>
> The "downloading files" issue only occurs when the computer name of the
> "new
> instance" is the same as the previous one -- because syncany assumes that
> you are the same guy.
>
> Did that answer your questions?
>
> Cheers,
> Philipp
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/syncany/+question/164516/+confirm?answer_id=0
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/syncany/+question/164516
>
> You received this question notification because you asked the question.
>

Revision history for this message
Ernesto (ernesto-cdelgado) said :
#3

Well, after looking at the list be seen that indeed the latest version is
newsync and is built with maven. I just need to know how to compile and run
Syncany this way.
I would appreciate if you can explain briefly.

Thanks!

2011/7/12 Philipp C. Heckel <email address hidden>

> Your question #164516 on Syncany changed:
> https://answers.launchpad.net/syncany/+question/164516
>
> Status: Open => Answered
>
> Philipp C. Heckel proposed the following answer:
> Hallo Ernesto,
>
> Different instances of Syncany (assuming different computer names!!) never
> access the same files on the server. Each instance/computer writes its own
> update file. So there are no concurrency issues here.
>
> The only file that is written by multiple clients is the repository-* file.
> But since this only happens if new shared folders are added, it is very
> unlikely to be overwritten.
>
> The "downloading files" issue only occurs when the computer name of the
> "new
> instance" is the same as the previous one -- because syncany assumes that
> you are the same guy.
>
> Did that answer your questions?
>
> Cheers,
> Philipp
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/syncany/+question/164516/+confirm?answer_id=0
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/syncany/+question/164516
>
> You received this question notification because you asked the question.
>

Revision history for this message
Best Philipp C. Heckel (binwiederhier) said :
#4

Hi Ernesto,

the newsync branch is not yet compilable. It has syntax errors and hence
does not work at all. Once it is, I'll make it the new trunk and update the
development and install instructions.

If you'd like to check it out anyhow:
$ mvn install
$
syncany-assemblies/target/syncany-0.1-SNAPSHOT-assembly/syncany-0.1-SNAPSHOT/bin/syncany.sh

Cheers,
Philipp

Revision history for this message
Ernesto (ernesto-cdelgado) said :
#5

ok, then I'll wait to trunk version because it's true that this version has errors yet.

Thank you for your answers.