Show stats

From OpenSimulator

Revision as of 13:37, 19 November 2013 by Justincc (Talk | contribs)

Jump to: navigation, search

Contents

Introduction

"show stats" is a new statistics gathering mechanism is slowly being added to OpenSimulator to integrate previously separate and ad-hoc mechanisms. For this system, you can see a short statistics summary with the command "show stats" and a much longer list of statistics with the "show stats all" command (which unfortunately doesn't yet include those in the summary!).

Use the "help show stats" command on the console for more information.

See Monitoring for information on other statistics gathering mechanisms for OpenSimulator.

Statistics

This information is highly subject to change as suitable data gathering is an evolving area. Need to keep adding stats.

clientstack

These are stats for the LLUDP clientstack that sends and receives UDP messages for viewers connected with the Second Life protocol. Each stats with clientstack.<region-name>.

Stat name Units Description
InboxPacketsCount messages The number of messages that have been pre-processed by an inbound network thread but are now waiting to be processed by the main Incoming Packets thread. If this number exceeds 0 for more than one sample then your simulator cannot cope with the number of UDP messages that clients are sending. Region performance will be degraded from the user perspective.
IncomingPacketPoolCount messages The number of packet objects currently in the memory pool to deal with incoming messages. This pool is used to reduce memory churn and hence improve simulator performance. The actual number is never an issue since OpenSimulator will create new pool objects as required.
IncomingPacketsMalformedCount messages Number of malformed packets that the simulator received from viewers. A high and increasing number may indicate a network attack.
IncomingPacketsOrphanedCount messages Number of well-formed packets that the simulator received but did not relate to any currently logged in viewer. Because viewers can disconnect in the middle of a datastream, we would expect to see a certain number of such packets in the course of normal operation. However, if the number is very high (e.g. tens of thousands) and/or increasing then this may indicate a network attack.

scene

These are stats relating to the graphical simulated scene.

Each starts with scene.<region-name>.

Stat name Units Description
RootAgents avatars The number of root agents in the scene. A root agent is associated with an avatar since a root agent is needed for full sim functionality (e.g. moving around).
ChildAgents agents The number of child agents in the scene. A child agent has limited functionality and is used by the viewer mainly to observe events in another scene (i.e. so that the user can see what's occuring in neighbouring regions).
FrameTime ms The amount of time taken by OpenSimulator to complete the last frame. The standard frame time is 18.18ms. In normal conditions there will be some small variation above and below this number, probably due to the low resolution of thread sleeping. This number may occasionally jump if the underlying VM (Mono or .NET) takes a long time to perform a garbage collect. If this number is consistently higher then your simulator is overloaded.
PhysicsTime ms Amount of time spent performing physics engine operations in a scene frame. If this is consistently high enough to make the FrameTime exceed the 18.18ms standard then region performance will be degraded. You will need to reduce the number of physical objects in your region. For OpenSimulator 0.7.6, ODE is used single-threaded and so extra cores will make no difference to performance.
SpareTime ms The amount of time that was left over after OpenSimulator had performed all operations required in the current scene loop. During this period OpenSimulator sleeps the thread.
SlowFrames frames In theory, this records the number of frames which took more than the standard frame time to execute. However, this measure may be buggy.

server

These are stats relating to the server itself.

threadpool

These are server threadpool stats.

Each starts with server.threadpool.

Stat name Units Description
BuiltinThreadpoolIOCPThreadsAvailable threads The number of pooled thread objects waiting to handle incoming IO requests. OpenSimulator sets this to a very high number by default. If you ever see this approach zero then your simulator is severely overloaded with respect to processing raw incoming IO requests.
BuiltinThreadpoolWorkerThreadsAvailable threads The number of pooled thread objects in the Mono/.NET native threadpool available to handle requests. If you have async_call_method = UnsafeQueueUserWorkItem (or QueueUserWorkItem though "unsafe" is fine for our purposes) then is used for all OpenSimulator's threading requirements. If you have async_call_method = SmartThreadPool (which is the current default), then SmartThreadPool handles all the heavy thread launching requirements (and so see the server.threadpool.STP* stats). If this figure approaches zero then you simulator is severely overloaded.
STPInUseThreads threads The number of SmartThreadPool threads currently in use. If this drops to 0 then the simulator will experience general performance degradation. In this case, try greating increasing the MaxPoolThreads setting in the [Startup] section of OpenSim.ini (e.g. to 150).
STPMaxThreads threads Maximum number of threads that the SmartThreadPool will use. This is set by the MaxPoolThreads setting in the [Startup] section of OpenSim.ini (or OpenSimDefaults.ini).
STPWorkItemWaiting items The number of work items waiting because all SmartThreadPool threads are busy with current work items. You will see this start to climb if STPInUseThreads == STPMaxThreads. You never want to see this situation - if you have work items waiting then try increasing your MaxPoolThreads setting.

debug stats record

This is an experimental facilty starting in OpenSimulator 0.7.6 which will record the results of "show stats all" to a log file every 5 seconds. The aim is to record statistical information throughout a session for later analysis. The logging is enabled with the console command. It works on both the simulator and a ROBUST instance.

# debug stats record start
Now recording all stats to file every 5000ms

To stop logging, either shutdown the server or use the command

# debug stats record stop
Stopped recording stats to file.

The log file used has the same name as the main logfile for the executable with the word "Stats" appended. For instance, turning on stats logging for OpenSim.exe will write to the file OpenSimStats.log. For Robust.exe, this will write to RobustStats.log.

Currently and in OpenSimulator 0.7.6, this logging requires entries in OpenSim.exe.config (and Robust.exe.config for Robust). If you are using your own version of these files then you will need to adapt them for the logging entries.

The performance impact of such logging should be low, though the log file size can grow quite large.

Personal tools
General
About This Wiki