Managing multi-user access

Small museums, historical societies and small businesses (galleries, art dealers, etc.) can use Recollector to manage collection databases. But in these environments you often find that more than one person needs to access and update the collection, each from their own computer. It is important that changes to the collection made by multiple users do not conflict, because when one user saves a changed collection, they could possibly overwrite the changes recently made by a different user. To avoid these problems, Recollector provides a managed-access protocol that coordinates the updates among multiple users. This page describes the managed-access protocol and how you and your organization can use it.

The first step needed to use the managed-access protocol is to have your collection file reside in a place that can be accessed by the computers of all of your users. In some cases, this might be on a shared network disk drive. In other cases it will be on a shared cloud-based file server, such as Dropbox or Google Drive. In all cases, you have to be sure that all users who should be permitted to update the collection have access to this shared location and permission to create or modify files there.

Once all your users have Recollector installed on their computer and have access to the collection (which you can test out in each case by having each user open the collection in Recollector), you are ready to set up the managed-access protocol. It is best to have only one user running Recollector when you are setting up the managed-access protocol. That user should open up the collection in Recollector and then choose Managed Access from the File menu. This will bring up the following dialog:

Manage Acess Dialog

Choose an access password for the collection, and enter it and confirm it. Access passwords must be at least six characters long, and cannot include space characters. The access password should be shared with all users that should be able to modify the collection. If you want other users to be able to look at the collection, but not modify it, simply do not give them the managed access password.

You also specify a timeout interval. When the managed-access protocol is in place, only one user at a time can modify the collection. If this user (the one who currently has write-access to the collection), should suddenly be interrupted, and step away from the computer for an extended period of time, other users would be prevented from getting permission to make modifications. Specifying a timeout interval causes Recollector to automatically release the write-access privilege after Recollector has not been used for the specified period of time. The period of inactivity specified by the timeout interval can be set to 15 minutes, 30 minutes, 1 hour, 2 hours, 3 hours or 8 hours. In addition, "No timeout" can be chosen, in which case Recollector will never terminate a user's access privilege due to inactivity.

Specifying the access password and timeout interval is a one-time operation. Once it is done, the collection will be operating under the managed-access protocol. Under the managed-access protocol, each time Recollector opens up the collection for a user, the collection will be opened in read-only/locked mode. In this mode the collection can be viewed, but it cannot be modified. Recollector disables various buttons and menu items that would otherwise let the collection be modified.

When a user wants to make changes to the collection, the user selects Managed Access from the File menu. This brings up the following dialog:

Request Write Access Dialog

The user needs to enter the access password for the collection. In addition, the user should enter their name, so that the system can know who currently has write-access to the collection. (This name is not an official login name; members in a cooperative group should just specify some name that will enable others to know who is currently modifying the collection.) If the password entered does not match the collection's access password, the user will not be given write-access to the collection.

If the user requests write-access, but somebody else currently has write-access, the user will be notified, and the collection will remain open in read-only mode:

Denied Access Notification

If you choose to be notified, an alert will pop up when the collection is no longer being updated by a different user. This popup will only appear if you keep the collection window open. If you close the window, or exit from Recollector, no notification will appear. The popup looks like this:

Denied Access Notification

If, when the user initially requests write-access, no other user has write-access, the requesting user will be granted the access. The collection window will be closed and re-opened in read-write/unlocked mode, and all of Recollector's facilities (including those used to modify the collection), will be available.

When finished making changes, the user should close the collection, either by choosing Close from the File menu or exiting from Recollector. The user can also release their write-access lock by again selecting Managed Access from the File menu. Also, if the user leaves the computer inactive for the timeout interval, Recollector will automatically close the collection and release the write-access lock.

Notes on security

Recollector's managed-access protocol is not aimed at preventing malicious changes to your collection. Unlike elaborate database systems, Recollector does not attempt to prevent illegitimate access to your collection. Rather, it attempts to coordinate access by multiple users of a friendly, cooperative group, so that one user's changes don't inadvertently clobber another user's changes.

Dealing with problems

Recollector's managed-access protocol uses two special files to coordinate multi-user access to the collection. These two files reside in the same folder as the collection file itself, and have the same base-name as the collection file, but different filename extensions. The collection file has a .xml extension. The other two files have extensions of .mgd and .lck.

Notes on product versions

When using the managed-access protocol, you should be sure that all the computers that are using Recollector to access the collection are running versions of the software that incorporate this managed-access facility. Should even one user be running an older version of Recollector (one that pre-dates the addition of this managed-access capability to the product), your collection data is susceptible to corruption, since the older version of the software does not follow the access restrictions imposed by the managed-access protocol.