SL project news: week 42 / 3 – server news

There is a lot going-on server-wise at the moment, so best to break it down by heading.

Server Rebalancing

The Lab is currently engaged in a rebalancing exercise in an attempt to put neighbouring regions on the same server and generally do a logical organizing of the grid to help improve various aspects of performance. Speaking at the Server Beta User Group on Thursday 18th October, Oskar Linden explained that there has been a lot of moving around (in terms of regions) within and between the Lab’s co-location facilities, and so the re-balancing is warranted and needed.

This work takes time – a rebalancing operation earlier this year took around 6 weeks to complete. It requires that regions are organized into groups and then generally moved twice: the first time to a temporary sever, the second to the target machine, each move requiring a reboot, so people may notice additional and unexpected restarts to regions they are in as the work progresses. Two moves are required because the server topology is so tight, it often isn’t possible to move regions directly from one server to a target server, so an intermediary is required.

While this work will take time to complete, the result should be improvements in stability and performance with the likes of teleports, etc, and even improved region crossings.

More on the Server Deployments for Week 42

  • Main channel: Oskar provided some more information on the main channel update of Tuesday 16th October, saying, “The main channel got a tweak this week, but it was a really small change, and no sim code got changed. We recognised that we had some inefficient SQL queries where large groups were concerned, so we optimised them, and the effect was quite noticeable. The databases are more responsive [and] this helps at all levels.” He went on to clarify that these changes were not Baker Linden’s Group Services code changes, after some in the meeting appeared to think this might have been the case
  • BlueSteel received the updates which were tested in the network pile-on test in week 42. At the time, I commented that teleporting seemed a lot faster, but that might have been a placebo effect of being on Aditi. It was. Commenting on the test, Oskar said, “There were no simulator changes in that test code. We were just testing backend tweaks.”
  • Magnum received no update per se, as previously reported, but was merged with trunk and then redeployed
  • LeTigre received the biggest update, which included new LSL functions ad updates, and most importantly of all, a new version of Havok (see below). Of the LSL functions, Maestro had a warning about the new OBJECT_PATHFINDING_TYPE parameter in the pathfinding command llGetObjectDetails, “We misspelled a constant, OPT_UNKNOWN, so we plan to fix that.” The fix will probably be next week.

Havok

As mentioned above, Havok on LeTigre was updated to version 2012.1. The update enables Havok’s built-in terrain optimisation and should lead to improved performance as a result of the physics shape of the terrain being simplified. Prior to the deployment, there were concerns that it would lead to issues with mesh vehicles trying to cross between regions running different version fo Havok, as has previously been the case.

As reported in part one of this update, these concerns led to Andrew Linden contacting the deployment team in LL to check whether it would be possible to ensure none of the Blake Sea regions remained on LeTigre while two versions of Havok running on the grid to help alleviate at least some of the pain people would feel when using mesh vehicles there. This apparently happened, whether it was before or after the deployment is unclear, as some people did report issues following the roll-out. There was also a little confusion as to what had been swapped where.

At the Server Beta meeting, Oskar gave the impression that all Blake Sea regions were on LeTigre. However, at the Simulator User Group meeting on Friday 19th October, Andrew Linden indicated that records showed none of the Blake Sea regions are running on LeTigre, although they are spread across the other channels. Given that there were (according to Andrew) around six Blake Sea regions running on LeTigre to start with, it would appear to make sense that they have been rotated off to another channel, rather than attempting to rotate all of Blake Sea on to LeTigre.

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