[Opensim-dev] HG Versions and Changes

[Diva Canto]

On 12/12/2010 2:26 AM, Ai Austin wrote:
> The "interface" numbers I was referring to was something in a commit a 
> while ago which meant HG1.5 grids that previously could interoperate 
> stopped being able to do so.  kidd peko of "The Hypergates" started 
> referring to HG1.5 i6 and the newer HG1.5 i7 grids to help testers and 
> those interoperating know which sub-set they were in.

OK, thanks for the clarification about where these numbers come from. I 
understand the intention, but this numbering is misleading and, 
essentially, incorrect when it comes to HG. Let me clarify.

We have been using "interface version numbers" to refer to 
communications between simulators and their central services *within* 
grids. We introduced these numbers mainly because of OSGrid, where the 
central services are run by one group of people and the simulators are 
run by others, and therefore the software upgrades are not coordinated.

The HG uses some of the communications that are used within grids, and, 
as such, when these interface numbers change, it usually means that HG 
between grids in different interface numbers may stop working. I say 
"usually" but not "always"; it really depends on what changed, because 
the HG uses only a subset of the grid communications. In the case of the 
bump from interface 6 to 7, it affected the HG, because of the way 
appearance is handled. (appearance handling is done in exactly the same 
way intra- and inter- grids)

However, HG introduces a whole new set of communications that doesn't 
exist within grids. And, so far, there hasn't been any number for 
denoting this new set of comms, other than HG 1.0 vs. HG 1.5. As far as 
I know, no changes within the HG 1.5 series have introduced backwards 
incompatibilities. So if things don't work between grids in interface 
number 7, they are bugs that can be fixed, if the situations are 
properly reported.

HG version numbering doesn't exist yet, just like archive version 
numbers haven't been put to use yet. Now it's about time that we start 
introducing these version numbers. Justin is doing some of that for 
archives, I'll try to do it for HG too.