Central, remote library, multiple clients

eos · 01-27-2011, 09:32 AM

Hi

I would like to server the library to multiple calibre clients. Is this already possible?

If not, how would I best synchronize my multiple calibre libraries, also, do you have any thoughts about maybe implementing this feature sometime?

Thanks in advance.

Manichean · 01-27-2011, 10:35 AM

This is not trivially doable. The problem is that Calibre is no multi-user system- it assumes that only one instance has access to a library at any given time. You'd have to somehow make sure that this is actually the case if you set this up.
Synchronization would also be tricky, unless you'd somehow make sure that everybody read a local copy from the central repository, made their changes and wrote back the changes to the central repository, without anyone making any changes to the repository in the mean time. The problem is that the metadata.db and the folder structure together form the database, and if a user changes the repository after another one has checked it out to make changes, you'd rapidly get inconsistencies between metadata.db and the folder structure, which would have to be resolved (there are tools available in Calibre to repair the database if this happens, but you couldn't guarantee no data loss, I think).

I don't know if multi-client support is on any todo list.

Sweetpea · 01-28-2011, 08:06 AM

Hm, this raises another question for me...

I have the Calibre Server running on a server. But, could I set it to use the same DB as I use on my client? Theoretically, this shouldn't be a problem, considering the server has read-only access, right?

Manichean · 01-28-2011, 08:38 AM

There may be issues when the server is an older version than the client is. However, from what I know the server has readonly access only, so you shouldn't damage your library, it would only potentially break the server... I'm no expert on this, though. Tread with caution if you try it.

Stumbl · 01-28-2011, 09:18 PM

while I would only run one client at a time , I have my library on a desktop, with the calibre library folder shared.

Then navigated to that folder over the network when I switched libraries, while I was working on my laptop

I can edit the library from any machine , and I'm still only working on one library at a time so there are no sync issues

caveate : network speed will affect performance

your mileage may vary
make a mess!

01-27-2011, 09:32 AM	#1
eos Junior Member Posts: 1 Karma: 10 Join Date: Jan 2011 Device: none	Central, remote library, multiple clients Hi I would like to server the library to multiple calibre clients. Is this already possible? If not, how would I best synchronize my multiple calibre libraries, also, do you have any thoughts about maybe implementing this feature sometime? Thanks in advance.

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01-27-2011, 10:35 AM	#2
Manichean Wizard Posts: 3,130 Karma: 91256 Join Date: Feb 2008 Location: Germany Device: Cybook Gen3	This is not trivially doable. The problem is that Calibre is no multi-user system- it assumes that only one instance has access to a library at any given time. You'd have to somehow make sure that this is actually the case if you set this up. Synchronization would also be tricky, unless you'd somehow make sure that everybody read a local copy from the central repository, made their changes and wrote back the changes to the central repository, without anyone making any changes to the repository in the mean time. The problem is that the metadata.db and the folder structure together form the database, and if a user changes the repository after another one has checked it out to make changes, you'd rapidly get inconsistencies between metadata.db and the folder structure, which would have to be resolved (there are tools available in Calibre to repair the database if this happens, but you couldn't guarantee no data loss, I think). I don't know if multi-client support is on any todo list.

01-28-2011, 08:06 AM	#3
Sweetpea Grand Sorcerer Posts: 9,707 Karma: 32763414 Join Date: Dec 2008 Location: Krewerd Device: Pocketbook Inkpad 4 Color; Samsung Galaxy Tab S6	Hm, this raises another question for me... I have the Calibre Server running on a server. But, could I set it to use the same DB as I use on my client? Theoretically, this shouldn't be a problem, considering the server has read-only access, right?

01-28-2011, 08:38 AM	#4
Manichean Wizard Posts: 3,130 Karma: 91256 Join Date: Feb 2008 Location: Germany Device: Cybook Gen3	There may be issues when the server is an older version than the client is. However, from what I know the server has readonly access only, so you shouldn't damage your library, it would only potentially break the server... I'm no expert on this, though. Tread with caution if you try it.

01-28-2011, 09:18 PM	#5
Stumbl Thread Killer Posts: 20 Karma: 10 Join Date: Oct 2010 Location: Myrtle Beach, SC. USA Device: iPad	while I would only run one client at a time , I have my library on a desktop, with the calibre library folder shared. Then navigated to that folder over the network when I switched libraries, while I was working on my laptop I can edit the library from any machine , and I'm still only working on one library at a time so there are no sync issues caveate : network speed will affect performance your mileage may vary make a mess!