Second Life Grid: Quality Metrics

The Second Life Grid Quality Metrics are designed to show the level of stability and performance in an open and transparent way to the community. As we roll out each new metric, we will also tell you what we are doing to improve it.

Second Life Service Outage Graph

Second Life Service Outage Graph

The Second Life Service Outage Graph (above) shows both the planned and unplanned usage loss. Usage Loss (Y-axis) is the percentage of estimated online resident hours lost due to large-scale problems with the Second Life Service. Essentially, this is a measure for how much time people would have spent logged in, but were unable or unwilling to because of some sort of failure. These includes blocked logins, large numbers of Region failures, database failures, and other problems which keep people from using Second Life. We are not including localized failures such as Region crashes; these are the subject of a different set of statistics.

These numbers may look fairly small, but one percent of a month's usage is over seven hours of the service being unavailable and hundreds of thousands of logged-in Resident hours. We need to improve. You can read Ian's Blog post about the sources of these service outages and the work being done to reduce them.

  • Planned Outages are necessary to perform maintenance such as upgrading the software and hardware as well as administration of the system. Planned outages are occasionally performed on Wednesday mornings PST. We have had 3 - 4 planned outages per month since March 2007 except for August when we only had 2 and our long-term goal is to have one per month. The Second Life Planned Outages Calendar shows our next planned maintenance. Occasionally, we delay a week if we are not ready and we typically look no more than one month out. Once we have finalized our planned maintenance day we post it on blog.secondlife.com and also announce it on the Second Life login page. A good rule of thumb is to either avoid scheduling large events inworld on Wednesday or first check the Second Life Planned Outages Calendar.
  • Unplanned Outages results in loss of service to some or all of the Residents at an unscheduled time. You can also visit the Second Life Service Status page if you suspect Second Life is currently experiencing problems.

Second Life Percentage of Viewer Sessions Crashed Graph

Second Life Percentage of Viewer Sessions Sessions Graph

The Second Life Percentage of Viewer Sessions Crashed Graph (above) shows the percentage of Resident sessions that ended abnormally from viewer and Region crashes.

  • Viewer Crashes is the percentage of sessions where the user did not explicitly logout. This graph includes viewer crashes running on unsupported PC hardware and running older graphics card drivers. Upgrading to the latest graphics card driver may reduce your viewer's crashes. For more information we also have a knowledge-based article on upgrading your graphics drivers.
  • Region Sessions Terminated is the percentage of sessions where users were kicked off a Region. For example, if you received the error message “you have been disconnected from the simulator”. This can occur because the Region went down from a: rolling restart, planned or unplanned grid outage, simulator crash or a communication problem between your viewer and the Region you are currently in.

Second Life Viewer Frame Rates Graph

Second Life Average Viewer Frame Rates Graph

The Second Life Average Viewer Frame Rates Graph (above) shows the average Frames Per Second (FPS) for the viewer. Viewer FPS is the most direct measurement of the end-user's experience of responsiveness of the system. Lower FPS systems appear laggy to the end-users as they control their avatar. It's common for two users in the same Region to each have drastically different viewer FPS due to PC hardware, network and configuration settings differences. The PC's graphics card is the most influential factor in determing the Viewer's frame rate.

For Residents with slower or older graphics cards and/or hardware, please take the time to turn down your draw distance so that you can experience less lag. For help on how to adjust your Second Life graphics settings to improve your viewer performance you can visit our knowledge-based article on Preferences Window Guide. After logging into the support portal, then scroll down to the Graphics and Graphics Detail Tabs. Upgrading to the latest graphics card driver is highly recommended and may improve your FPS. Upgrading to a faster or recommended graphics cards and system will often result in the biggest improvement to your viewer frame rate. For more information we also have a knowledge-based article on graphics cards.

For the graph above, we record the average FPS for all viewer sessions and bucket them into statistical “quartiles” as described below:

  • 75th Percentile Viewer FPS is the FPS for the 75th percentile of Residents where the green bar represents the portion from the 51st to the 75th percentile.
  • Median Viewer FPS is the FPS for the 50th percentile of Residents where the yellow bar represents the portion from the 26th to the 50th percentile.
  • 25th Percentile Viewer FPS is the FPS for the 25th percentile of Residents where the red bar represents the portion from the 0th to the 25th percentile.

Second Life % Time Below Region FPS Thresholds Graph

Second Life Service Monthly % Time Below Region FPS Thresholds Graph

The Second Life Monthly % Time Below Region FPS Thresholds Graph (above) shows the average percentage of time that the Region's performance was suboptimal. For example, in September 2007, only 4% of the time the Regions were slow and of that, a little less than 1% of the time, the Regions were very slow. The most common cause of slow Regions is when there are a large number of Residents in that Region. Other reasons that can slow down a Region include extensive use of moving physical objects, large textures and active scripts. For help on tuning your Region visit our Region Performance Improvement Guide

  • % of Time with Region < 35 FPS shows the percentage of time where Regions with lower frame rates may become noticeable.
  • % of Time with Region > 20 FPS shows the percentage of time where Regions with low frame rates are very slow and laggy.

Service Quality Metrics Statistics

Download the service quality metrics statistics on this page in the following formats:

Stay tuned for blog posts with more information.