Conflict Handling

An editing conflict occurs when two people try to edit the same page at the same time. Different Wiki engines handle these conflicts in different ways.

Some engines simply ignore the fact, which means the person who saves the page last overwrites all changes made by the first person. Not desirable but with the use of the page revisions the lost content can be recovered and re-added manually if anyone discovers the problem.

A brute-force solution is to make sure only one person can edit a page at one time by using page locks and thus avoid conflicts. Because of the statelessness of the HTTP protocol locking pages is not efficient or indeed wise in any way. Locking must be timed or else manual system administrator intervention will be needed to release locks (since a user may start editing and simply close the window without releasing the lock, either on purpose or by accident).

A third method is to use a conflict resolution technique which tries to solve conflict automatically. For example the two users may have edited different parts of the same page. A conflict resolution would simply merge both changes into the new page revision. However, there may be conflicts during a merge. The engine goes a step further and notifies the second user of the possible conflict and sometimes even shows parts colliding (using Revision diffs). The user then can choose to abort his save or merge manually (similar to the CVS mechanism).