Dear All, Performance of any product is of prime importance, since it results in user actually using or not-using the system.
My question to all is how do you collect and evaluate performance metrics and measures, specially when you are evaluating virtual vs. real hosts and linux vs. mac vs. windows ? Is it just visual perception ? What about network configurations ? Can you please post exact specs of the system, network topology, and raw/processed performance metrics data ? Is it subjective or objective evaluation ? I did post something similar on this list few weeks back, and Justin and Dan were kind enough to provide some links, however, those links lead me to believe that the performance testing was only restricted to few metrics such as CPU load, memory load and not much raw/processed data was available other then couple of tables listing some configuration and values. Look forward to hear from you... regards -- amit ________________________________ From: [email protected] [[email protected]] on behalf of Butch Arnold [[email protected]] Sent: Saturday, October 11, 2014 5:43 PM To: [email protected] Subject: Re: [Opensim-dev] Open Simulator Server on Windows vs Linux Hi All, I haven't compared Linux vs. Windows in some time, but in the past when comparing, a linux based instance seemed to require more ram than the same region running on a windows machine. We at 3rd Rock use only windows for our grid and centOS for our web server. It is true that I personally am much more comfortable using windows than I am Linux, but I am not against Linux. In our early days back in '08 I had originally started 3rd Rock using Linux, but changed over to Windows as I am more comfortable with that platform. This topic has all the dangers of quickly turning into a Ford vs. Chevy, or coke vs. pepsi argument, so to be fair, some may prefer linux over windows for different reasons, but the reason 3rd Rock runs windows is that my personal observations and tests revealed to me that opensim on linux uses more ram "And" I am more comfortable with the windows platform. ~Butch On 10/11/2014 4:06 PM, Dahlia Trimble wrote: I have noticed decreased performance when running OpenSimulator in a VirtualBox VM vs. running it on the host. Usually it's when there is a lot of I/O operations, such as high database activity or networking load. I've also seen issues when a lot of timers are used in scripts. This makes sense as VIrtualBox adds significant overhead to such operations. I've seen much better performance using OpenVZ, however OpenVZ is harder to work with as it's not really a virtual machine but rather more of a constrained operating environment. It does not add as much overhead to I/O operations as a true virtual machine would. It also did not seem to suffer from the timer issues I've seen in VirtualBox. I've used OpenSImulator on a variety of virtual servers now for several years and in general it does work reasonably well for smaller use cases. I would not consider using anything but bare metal or OpenVZ for any regions which were expected to have high performance and service many users simultaneously. In general I've found Windows+.NET to be much more robust than Mono. I do see problems occasionally on Linux+Mono but I tend to blame Mono. I have experimental code which can crash and burn any Mono version I've tried to date, yet runs flawlessly on .NET. This code creates and dereferences millions of very small objects and when run on a Mono installation will leak memory and crash with out of memory errors. I've discussed it with several Mono devs on IRC and the consensus was a possible bug in one or more of the Mono runtime libraries. I've also seen a lot of random Mono crashes that I just never see in .NET while running the same sim under similar load conditions. While in general I believe .NET to be a more robust operating environment than mono, the lower cost and ease of use of Linux for server-like applications usually means I use Linux servers for running regions. I usually use Windows exclusively for OpenSimulator development, which may be a reason why I tend to notice such differences. I don't really have any documented empirical evidence to support my reasoning other than having some code which will crash Mono. Most of my rationale is based on observations during my OpenSimulator development and deployment activities over the past several years. On Sat, Oct 11, 2014 at 8:46 AM, Maxwell, Douglas CIV USARMY ARL (US) <[email protected]<mailto:[email protected]>> wrote: The MOSES project ( http://militarymetaverse.org/ ) has experimented with a number of different Open Simulator deployment methods. The grid is currently has access to a blend of 5 Dell PowerEdge R815 servers and one Dell PowerEdge R220. The R815's are virtual machine servers and the R220 is a small Linux host used to serve up to 10 sims. On the R815's we can stand up any operating system we wish to experiment with using virtual machines. Currently, our favorite installation method is using Ubuntu Linux. This is only for convenience as all of the dependencies are available as packages. On Ubuntu, we can start with a bare OS install through completely functioning MOSES grid in about 3 hours, including compiling from source. Less time when dealing with binaries. Our Complete Instructions Here: http://militarymetaverse.org/wp-content/uploads/2014/10/MIAB_Installation_Instructions_using_Virtual_Box_and_Ubuntu-141006.pdf We have worked with CentOS, but it is a lot of work. Mostly because of the bootstrapping needed to get Mono and its associated packages working. It is easy to make mistakes and you can spend hours troubleshooting. In the end, it seems to operate similarly as Ubuntu. The version of Windows we typically work with is the Army Golden Master of Windows 2008 Server or Windows 7 AGM. The biggest issue we deal with is just setting up the environment and being forced to manually download and install all the dependencies. This can take days. The Army version of Windows also has extra registry values and network policies that pose configuration challenges. Virtual Machine Performance Differences? In our testing we have not *yet* found any measurable difference in performance between Open Simulator deployed via VM or bare host on any operating system. This has been independently verified by our industry partners and other military labs using their own internal hosts as well as Amazon EC2. Operating System Performance Differences? Unfortunately there are so many variables that affect open simulator performance that anecdotal evidence to support Windows or Linux simply don't hold up. Its not a simple matter of comparing .Net to Mono. The operating systems are fundamentally different, so a proper test would involve replicating the Open Simulator servers as closely as possible on each. This would require an initial benchmark test that has both Windows and Linux servers using the same version of Mono, same version of Apache, same version of MySQL, etc... on the same host configuration (i.e. hardware or VM profile). Any deviations introduce variables to the test that must be accounted for. For example, only after the Windows vs. Linux test has been completed and analyzed for differences can you then introduce another variable of .Net vs. Mono and re-run the performance benchmarks. The original Windows vs. Linux benchmark is the baseline. Douglas Maxwell, MSME Science and Technology Manager Virtual World Strategic Applications U.S. Army Research Lab Simulation & Training Technology Center (STTC) (c) (407) 242-0209<tel:%28407%29%20242-0209> _______________________________________________ Opensim-dev mailing list [email protected]<mailto:[email protected]> http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev _______________________________________________ Opensim-dev mailing list [email protected]<mailto:[email protected]> http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev
_______________________________________________ Opensim-dev mailing list [email protected] http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev
