Possibly better suited for "Rack Overflow", but from a developer's point of view, what are the advantages and disadvantages of running IIS (serving both legacy classic ASP and .NET) as a 32bit process instead of a 64bit process on a 64bit windows host?
The main advantage of 32/64 (iis/server) over 32/32 seems to be the ability to go up to 4gb in memory per IIS process.
The advantages I expect of 32/64 over 64/64 appear to be that it's easier to access legacy 32-bit in-process DLLs (of which we still have one from a partner vendor we can't move away from immediately) and perhaps a smaller memory footprint for the same code given smaller memory pointers.
Are there any performance benefits of 64/64 over 32/64 or anything else that would warrant a full switch now? Have I made any false assumptions here?
The only perf advantage to running IIS on 64bit vevrsus 32-bit is to allow access to a much larger memory address space.
If you are doing normal ASPX page processing, then it's likely you don't need to address more than 4gb from any single process. Suppose you run in 32-bit mode with a web-garden with multiple worker processes on the same machine. In that case each process can address up to 4gb.
The big advantage can come when you perform caching. A 64-bit process can maintain a huge in-memory cache (assuming you have the 32GB or more of RAM to support it) to allow you to cache complex page content or data, on the web server. This allows perf gains when the data is more expensive to generate than it is to retrieve - for example if the data is an elaborated form (let's say the result of a monte carlo simulation), or if the data resides off-box and the network IO time is much more expensive than cache-retrieval time.
If you do not use caching, then 64-bit IIS is not going to help you. It will require 64-bit pointers for every lookup, which will make everything a little slower.
64-bit servers are much more effective when used for databases like SQL Server, or other data management servers (let's say, an enterprise email server like Exchange), than for processing servers, such as IIS or the worker processes it manages. With a 64-bit address space, servers that need to manage data can keep much more of that data in memory, along with indexes and other caches. This saves disk IO time and elaboration time when a query comes in. Most Web apps don't need to address more than 4gb from a single process.
Maybe a useful analogy: In transport, an large SUV is like a 64-bit machine, while a regular, compact passenger car is like a 32-bit server. You can carry much more stuff in a large SUV, and it has a larger towing capacity, seating for 8 people, and a GVWR of 8600 lbs. But with all that, you pay. The truck is heavier. It uses more fuel. If you are only carting around 2 people and one duffel bag, you don't need an SUV. You'll be better off with the smaller vehicle. It can be speedier and more efficient.
I don't think you've made any false assumptions. But I'd say, no, there's likely to be no performance difference between any of the scenarios you outlined. 32 on 64 on Windows does not operate at a penalty. 64 on 64 may give some slight performance boost, but that's dubious. There may be some memory savings with a 32-bit process, but this is likely negated by the thunking required to run the process in the first place.
The only benefit is the DLL issue you mentioned. That could be a reason for upgrading as well (if you have something specifically 64-bit that you need to use).
I've had an experience where moving from a 32bit Windows 2003 Server to a 64bit Windows 2003 Server both running IIS 6 and the performance of the ASP.NET 3.5 website was unacceptable.
The 64bit server would run a clear 2 seconds behind the 32bit one consistently.
After switching IIS 6 to run as a 32bit worker process, the performance was equal and comparable once again.
I haven't verified it, but I think it might only apply to IIS6 win2k3, as testing I've done with IIS7 x64 (Vista) and a 64bit IIS worker process seems to perform just fine.
The process to swap to the 32bit process was quite simple. Here is the KB article with the supporting details:
http://support.microsoft.com/kb/894435/en-us
ASP.NET 2.0, 32-bit version
To run the 32-bit version of ASP.NET 2.0, follow these steps:
Click Start, click Run, type cmd, and then click OK.
Type the following command to enable the 32-bit mode:
cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1
Type the following command to install the version of ASP.NET 2.0 (32-bit) and to install the script maps at the IIS root and under:
%SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis.exe -i
Make sure that the status of ASP.NET version 2.0.50727 (32-bit) is set to Allowed in the Web service extension list in Internet Information Services Manager.
See the KB article for setting back to 64-bit.
For memory availability, refer to this msdn blog.
Memory availability. For my application, we got what we needed switching from 32 bit process on 32 bit OS to 32 bit process on 64 bit OS, without the trouble of replacing 3rd party libraries. So, we stopped there. Benefits are: 1) 2-3x effective memory available to each IIS worker process and 2) In a 32 bit OS where the web site uses a lot of memory, other system processes and web sites compete for limited total memory. For your application, look at how much memory do your worker processes use. If each WP isn't using a lot of memory (well over 1GB), 64 bit worker processes won't help much.
For performance, I think you have to test your own applications in both configurations. Dave's post above indicates that you might have performance degradation with 64 bit. As cheeso notes, some applications may see benefits from caching (2GB + of cache is a lot, though). Except for limited and simple applications, I don't think we are going to be able to make performance generalizations. We might be able to point to specific technologies that perform better or worse.
Besides the obvious memory differences, 32 bit processes on a 64 bit OS have to run in something called "Windows on Windows" or WOW mode. It's basically a thunking/emulation layer. There is a performance penalty if you pay close enough attention.
This is actual advice from Microsoft: "We recommend that you configure IIS to use a 32-bit worker processes on 64-bit Windows. Not only its compatibility better than the native 64-bit, performance and memory consumption are also better."
Please refer to this link posted in one of the comments above and published 05/14/2020:
https://learn.microsoft.com/en-us/iis/web-hosting/web-server-for-shared-hosting/32-bit-mode-worker-processes
I cannot claim to understand exactly why, but this advice is very clear, with 64bit workers virtual address space is bigger so a 32bit worker is generally more efficient
Related
Please excuse my inexperience, this is my first time on the site.
I have a Dell PowerEdge r710 with 2 Xeon L5630 CPUs and 16G RAM installed. I'm trying to host a Minecraft 1.7.10 Forge Server that runs perfectly fine on my Desktop, but refuses to run properly on the server.
This machine is running Java 8, and runs perfectly otherwise. When running the application without the mods, it loads up without a hitch. As I add more mods, it gets worse. As far as my (very, very limited) knowledge goes, the order of JVM arguments doesn't matter, and didn't on my Desktop, but in order to get the application to even run I had to change the order in my .bat file. With all mods installed, the Out Of Memory Error occurs with a chunk loading error when around 41% spawn loaded.
This is the .bat file that I've made to start the server:
java -jar minecraft_server.jar -Xms512M -Xmx8192M nogui -XX:+HeapDumpOnOutOfMemory
This should load up perfectly fine, everything is compatible and tested on another machine, but the exact same setup will not run on the r710, saying Out Of Memory with more than double the desktop's allocated memory.
First you should use Task Manager or a similar utility to make sure that Java process indeed is using more then the amount you allocated with your arguments. Then I would recommend reading through this lovely post written by Cpw and posted on Reddit. If it doesn't help you with your current situation it should at least give you a bit more information on Minecraft's memory footprint.
In a normal situation where you would be running Minecraft as a local server from your computer I would suggest taking a look at how much memory your GPU is taking up. Since you are running a server this is not relevant, but might still be useful to someone who stumbles upon this post so I will leave it here:
Your graphics card is probably the biggest address hog. Today's graphics adapters often contain a gigabyte or more of RAM, and every one of those bytes needs an address. To be fair, I doubt that many of those multi-gigabyte graphics cards are in 32-bit PCs, but even a 512mb video card will take a sizeable bite out of 4GB.
I am not quite familiar with running dedicated servers but another important thing that is worth mentioning is that in case you are on a 32-bit operating system you will only be able to take advantage of 4GB of your RAM due to architecture constraints.
Every byte of RAM requires its own address, and the processor limits the length of those addresses. A 32-bit processor uses addresses that are 32 bits long. There are only 4,294,967,296, or 4GB, possible 32-bit addresses.
If all else fails you should try to seek help on one of the available Discord channels dedicated to Minecraft modding. This should be a rule in general actually, especially for general purpose problems that are difficult for others to reproduce. Here is a small list of three Discord communities dedicated to Minecraft modding that I have experience with:
Modded Minecraft - The one with most traffic so it can be a bit more difficult for your question to get noticed on busy days, but definitely the best moderated one from this list.
Modding Help - The smallest of the three. I don't have much experience with this one.
Mod Dev Cafe - This one has a decent size and a pretty good response rate, but be prepared for the usual facepalms and other unpleasantness common to younger admins and moderators. However if you are willing to look past that this is a good choice.
I have a Windows Server 2012 with IIS 8.0. It is hosting many small websites with a low user base which are not mission critical in any way. With small website I mean that the application code and memory footprint is quite low, but due to the loaded libraries, like EntityFramework, the memory consumption of the applications are about 140MB when freshly started and idle.
In general that’s not a big deal for a full-blown webserver, but I only have a VPS with 4GB of RAM which also runs several other applications (databases, BIND, hMail, etc.). I’m using it basically as development server to play with many different technologies. Therefore, I’m running out of RAM quickly while serving dozens of ~140MB w3wp’s.
Beside of suspending when idle I’d like to reduce the memory consumption while still using any framework or library I’d like to use – that’s the purpose of the whole thing actually.
Long story short: As the applications not only share the same .NET version but also some libraries like EF or MVC, would it make more sense to run multiple sites in one app_pool so that they can share the libs? Or would each site load its own copy anyway (due to different Application domains like discussed here)?
Bonus question: when considering a hardware upgrade 1GB of RAM is 20$/month but putting the whole server on SSDs is 10$/month. While I do know that reading from page file is always much slower than reading from RAM I’m thinking about using a big pagefile on the SSD instead of buying 1gig of additional RAM for twice the price – again, speed of the websites isn’t critical, they should just work. Would that make any sense at all?
Looking at a w3wp Process (hosting multiple sites) in Process Explorer shows that it hosts several different application domains with different instances of the same assemblies loaded into memory. So moving the sites into a single AppPool may not help much.
But there is another option. In IIS 8+ you can share common assemblies across AppPools. If certain assemblies are used by multiple AppPools, they are loaded into memory just once and then aliased by the different processes.
Have a look at this bit from asp.net and this TechNet blog post
You have to do a little bit of setup work, but then it seems to work quite well.
We have the following setup:
Virtual server, Intel Xeon X5650 # 2.67Ghz (4 processors)
8GB RAM
Windows server 2008 Standard 64bit
Sql Server Express
IIS 7.5
Our database is only 200mb. We are running an ASP.net app. We recently ran into some performance issues, ~200 concurrent connections was causing 100% CPU usage (mostly consumed by IIS) and bringing the response time to around 20sec! After some tweaks to our code we have been able to run a load test from loader.io with 1500 concurrent users over 1 minute and our response time at the end was around 5 seconds and CPU was around 95%, again consumed mainly by IIS, our memory was sitting at around 4GB usage. However we are expecting bigger spikes than 1500, anywhere up to around 4000 users in a short amount of time.
My questions are the following:
1) Is this normal performance for our current setup? Our site is quite intensive on the database and we are using Entity Framework.
2) Would upgrading to Sql Web edition have any benefit seeing as though our Database is so small?
3) Do you think that this type of setup could handle 4000 users?
4) Any suggestions on what we could do to handle this load?
I know this is somewhat subjective, but any answers are much appreciated.
Is this normal performance for our current setup?
Depends on your code. Did you profile the code to make sure you dont have anything stupid in there?
Our site is quite intensive on the database and we are using Entity Framework.
Again, did you pofile to figure out you spend a lot of time in entity framework? It is slow, ut the question is what "intensive" means. This is what profilers are for.
Would upgrading to Sql Web edition have any benefit seeing as though our Database is so
small?
Help, my pizza comes too late. Wiould upgrade to a larger car help? You say yourself that you spend the time in IIS, not sql server.
Do you think that this type of setup could handle 4000 users?
You think my car is big enough? Note I don't tell you what I need it for. Without looking at usage patterns and your code - no idea. THAT SAID: the server is pathetic compared to what you buy today. As such, this is a irrelevant question - just upgrade if you have to.
Any suggestions on what we could do to handle this load?
Load test + profiler, optimize code. Get bigger server. Realize that we dont have crystal balls to figure out how good / bad / stupid your code is.
Number one question arising here, is: did you deploy RELEASE or DEBUG compiled binaries of your project?
Upgrade to WebEdition will not solve any problem here, since the difference in the versions is very simple: WebEdition is just throttled in the internal scheduler/etc. - so you will be just fine with the standard edition.
My experience is that the most crucial aspect of concurrent request is the amount of server memory and the consumption of this memory by your code.
As the physical memory is consumed, the server starts to swap from physical to virtual memory which slows down processing dramatically and leads to symptoms you describe.
I would start with putting another 8gb of ram into the server. In the meantime try to optimize your code so that less data is processed during requests or less memory is used. Also, move sql server to a separate machine so that there is no competition between iis and sql server when it comes to memory availability.
With your current machine, I doubt the problem is the IIS itself, but rather related to the way your app is designed and/or utilize frameworks. I personally learned just recently that IIS requests including multiple rounds trips to the database can be measured in hundreds of micro-seconds, not hundreds of milliseconds... A single locking bug, or unbalanced queuing can limit your application scalability and regardless of your hardware specs [https://twitter.com/michaelzino/status/454512110165184512].
Entity Framework is known for validating your models against the database schema for the first initial calls. I would suggest profiling your app layers, starting from the data access layer, or the intrinsic database calls, and going up.
SandCastle is unable to process our class library because it crashes with an OutOfMemoryException exception during XSL transformation.
What can we do about that, except for the obvious, buy more memory? The problem is that this is our developer machines with 3.3GB memory on a 32-bit OS so basically we either have to upgrade to 64-bit and more memory (which won't happen for a while) or set up a virtual server to do this with lots of memory (which will impact production servers).
I seriously doubt we have the biggest class library in the world that requires help files, so what options do we have? Is there a magic "Do not crash with out of memory errors" setting that we forgot to turn off?
If you're on 32 bit Windows, your user process will only be able to address 2 GB memory per default (3 GB is run as large address aware). The 2 GB are used for everything in the process, so the .NET runtime, standard libraries, booking and so forth all take their chuck. In my experience that leaves about 1.5 GB for .NET applications on 32 bit.
You can get access to more memory by using the large address aware switch, but it doesn't come for free if you're on 32 bit Windows. Moving to 64 bit Windows will let your 32 bit application access the entire 32 bit address space and thus give you 4 GB addressable space.
I've recently written a blog entry with details about memory usage for .NET applications, but since I blog in Danish, you may not be able to read it. However, if you want to have a look, the link is: http://kodehoved.dk/?p=156
You may also find this MSDN blog post relevant: http://blogs.msdn.com/maoni/archive/2007/05/15/64-bit-vs-32-bit.aspx
So I've seen this question, but I'm looking for some more general advice: How do you spec out a build server? Specifically what steps should I take to decide exactly what processor, HD, RAM, etc. to use for a new build server. What factors should I consider to decide whether to use virtualization?
I'm looking for general steps I need to take to come to the decision of what hardware to buy. Steps that lead me to specific conclusions - think "I will need 4 gigs of ram" instead of "As much RAM as you can afford"
P.S. I'm deliberately not giving specifics because I'm looking for the teach-a-man-to-fish answer, not an answer that will only apply to my situation.
The answer is what requirements will the machine need in order to "build" your code. That is entirely dependent on the code you're talking about.
If its a few thousand lines of code then just pull that old desktop out of the closet. If its a few billion lines of code then speak to the bank manager about giving you a loan for a blade enclosure!
I think the best place to start with a build server though is buy yourself a new developer machine and then rebuild your old one to be your build server.
I would start by collecting some performance metrics on the build on whatever system you currently use to build. I would specifically look at CPU and memory utilization, the amount of data read and written from disk, and the amount of network traffic (if any) generated. On Windows you can use perfmon to get all of this data; on Linux, you can use tools like vmstat, iostat and top. Figure out where the bottlenecks are -- is your build CPU bound? Disk bound? Starved for RAM? The answers to these questions will guide your purchase decision -- if your build hammers the CPU but generates relatively little data, putting in a screaming SCSI-based RAID disk is a waste of money.
You may want to try running your build with varying levels of parallelism as you collect these metrics as well. If you're using gnumake, run your build with -j 2, -j 4 and -j 8. This will help you see if the build is CPU or disk limited.
Also consider the possibility that the right build server for your needs might actually be a cluster of cheap systems rather than a single massive box -- there are lots of distributed build systems out there (gmake/distcc, pvmgmake, ElectricAccelerator, etc) that can help you leverage an array of cheap computers better than you could a single big system.
Things to consider:
How many projects are going to be expected to build simultaneously? Is it acceptable for one project to wait while another finishes?
Are you going to do CI or scheduled builds?
How long do your builds normally take?
What build software are you using?
Most web projects are small enough (build times under 5 minutes) that buying a large server just doesn't make sense.
As an example,
We have about 20 devs actively working on 6 different projects. We are using a single TFS Build server running CI for all of the projects. They are set to build on every check in.
All of our projects build in under 3 minutes.
The build server is a single quad core with 4GB of ram. The primary reason we use it is to performance dev and staging builds for QA. Once a build completes, that application is auto deployed to the appropriate server(s). It is also responsible for running unit and web tests against those projects.
The type of build software you use is very important. TFS can take advantage of each core to parallel build projects within a solution. If your build software can't do that, then you might investigate having multiple build servers depending on your needs.
Our shop supports 16 products that range from a few thousands of lines of code to hundreds of thousands of lines (maybe a million+ at this point). We use 3 HP servers (about 5 years old), dual quad core with 10GB of RAM. The disks are 7200 RPM SCSI drives. All compiled via msbuild on the command line with the parallel compilations enabled.
With that setup, our biggest bottleneck by far is the disk I/O. We will completely wipe our source code and re-checkout on every build, and the delete and checkout times are really slow. The compilation and publishing times are slow as well. The CPU and RAM are not remotely taxed.
I am in the process of refreshing these servers, so I am going the route of workstation class machines, go with 4 instead of 3, and replacing the SCSI drives with the best/fastest SSDs I can afford. If you have a setup similar to this, then disk I/O should be a consideration.