[ The below article is an updated version of one I wrote for the most recent issue of the in-world newspaper, the OSGrid Gazet. ]
In your travels around the grid you have likely encountered a region which was in the grid map but not actually accessible. Sometimes this unavailability is normal, such as when a sim crashes. But these days the map contains many regions which no longer exist. Until several months ago regions which were down for 24 hours were purged from the grid database, and therefore the map, but that mechanism broke when OpenSim changed and began storing coordinates in the grid database in meters and, well, we never got around to fixing it. But we’re fixing it. We have already begun regular region checks, and will begin purging regions which remain inaccessible. We’ll start by purging regions which remain down for one week, though we may shorten that time period down the road.
So what does “purge regions” mean? It simply means removing an inaccessible region from the grid. What it does *not* mean is removing data from any regions. If, for example, you are a region operator, your sim crashes and is inaccessible, and you go on vacation for two weeks your region would be purged from the grid region list. The data on your region would remain untouched. To return a purged region to the grid, just restart it. You may or may not have to change your region’s coordinates, as we currently have no way for a down region to reserve spaces in the grid, but otherwise you can bring your region back up exactly as it was before.
Why are we doing this? Teleporting to a region only to find it no longer exists isn’t fun. And because of the way OpenSim region-to-region communication works, it wastes resources trying to communicate with neighbors which no longer exist. Purging these dead regions will lead to a better experience for grid users and region operators.
We’ll begin purging dead regions on or after 00:01 UTC on Friday, June 25 (that’s Thursday 5pm US/Pacific). A number of people have posted instructions in http://osgrid.org/forums on how to automatically restart sims when they crash, if that’s of interest to any region operators.
We’re expecting approximately 4,000 of the currently registered regions to no longer be in operation and disappear from the map when the purging resumes. This isn’t a bad thing; many of these dead regions were simply test regions or remnants of first-time region operators learning about OpenSim. In fact, we know 500 of these dead regions were from one test by one person. But the grid is still healthy and growing.
So when the region count on the osgrid.org home page drops, don’t be alarmed. We’re just doing a little spring cleaning.
[ You can find the comment thread for this post over in the forums. ]