In order to improve performance* of a WCF service, one of the following can be done:
Use WCF inbuilt features (throttling etc)
Install multiple instances (separate websites in IIS) of the same service in the same machine.
I understand that these things are better tested than discussed but just wanted to get an opinion if someone has already tried both these approaches.
This service uses InstanceMode.PerSession and ConcurrencyMode.Multiple
Performance: This service handles data (MTOM encoded). There should not be any timeouts since clients will make synchronous calls to this service.
No, multiple endpoints from a single service won't help, as you describe it.
Yes, you can have a running WCF in IIS with multiple endpoints, but the same service is processing the requests whether they come into endpoints 1, 2, 3 or n. And since WCF requests are processed on their own threads, there's no benefit to adding extra end points.
Think of it this way: 10 requests come into a WCF service. Each request is processed on its own thread whether there are 10 endpoints or just 1. So there's no speed advantage gained by adding endpoints.
I've spent 2 years building industrial-scale WCF services. If you're worried about performance, the WCF service is the least of your worries. I've load tested a WCF service, sending 1000 concurrent users (each uploading multiple 157kb files) at a medium size (4 core) server; the server barely breaks a sweat while uploading 160 files/second.
If you're planning to build huge web service, the way to spread out the processing load is to have 1-n WCF web services fronted by a load balancer like F5. Then you can scale up to Amazon.Com size if you like.
Related
I have a desktop app that uploads 10 jpegs of size 2000 bytes in 1 second via my web service which is hosted under IIS
The Operation Contract is 1 way (ie not duplex) and I use MTOM in the binding.
Will there be any performance gain if I self-hosted it instead under a Windows Service?
There is a question with a interesting analyse about using different bindings for streaming data:
Streaming with WCF and MTOM
You may get improved response times because the ServiceHost will already be loaded into memory and ready to receive calls. This is not true of IIS hosting which may unload the appdomain during times of low traffic. So when a call does come in IIS will need to fire up the ServiceHost before it can process your call.
However, IIS provides you with some useful features such as reliability - a windows service can just crash and remain down for as long as it takes someone to notice.
We have a wcf service hosted in IIS (Win 2012). We expect thousands of messages coming throughout the day, however the peak would be around 4K concurrent messages. All these are one way (async) requests and wcf service performs some processing which will take several seconds for each request.
- Is there any limitations on max concurrent requests that can be sent to wcf svc hosted on IIS? Does it depend on thread availability on server? Any settings that needs tweaking would be useful.
In another scenario, we have less number of async requests coming to wcf svc, however for each request service performs few things parallely (Parallel.ForEach). What would be maximum parallel threads available in this scenario and does it depend on any other factors? Any settings that needs tweaking would be useful.
Even if this question is a year old, I am still searching a good answer for this question. I appreciate any information that will lead me to fully understand this issue regarding low performances of communicating web services hosted on the same machine.
I am currently developing a system with several WCF Web Services that communicate intensively.
They are running under IIS7, on the same machine, each service being in a different Application Pool, with multiple workers in the Web Garden.
During the individual evaluation of each Web Service, I can serve 10000-20000 requests per minute, quickly and without any issues for the resource consumption (processor and memory).
When I test the whole system or just a subsystem formed by two Web Services I can't serve more than 2000 requests/minute.
I also observed that communication time between Web Service is a big issue (sometimes more than 10 seconds). But when testing with only 1000 requests per minute everything goes smoothly (connection time of no more than 60 ms).
I have tested the system both with SOAPUI and JMETER, but the times were computed based on system logs, not from the testing tools.
Memory and network aren't an issue (they are used very little).
Later on, I have tested the performance of 2 communicating WCF web services, hosted on two server and on the same server. It again seems that there is a bottleneck when the services are on the same machine, lowering the number of connection with from ten thousands to thousands; again, no memory or processor limiting.
As a note, I am working with quite big data in some cases and some of the operations needed are long ones.
I used perf.mon to see what's going on, for memory, processes, webservice, aspnet, etc. but I didn't see anything that could indicate what it's going wrong.
I also tried all the performance settings and tuning options I could find on the Internet.
Does someone know what can be wrong? Why the communication between Web Services could last so long? Why the Web Service which serves as an entry point in the system can accept 10000 requests/minute when is tested alone, but when communicating with another Web Service barely accepts 2000?
It's an IIS7 problem? Could my system perform better if each Web Service will be deployed on a different server?
I want to understand better how things internally function (IIS and WCF services) to improve performances for current and future systems.
You could try to collect data from WCF performance counters : concurrent calls, instances, duration, ... In addition, WCF throttling provides some properties that you can use to limit how many instances or sessions are created at the application level. Performance of the WCF service can be improved by creating proper instance.
Finally, in load testing, there are many configuations to apply to different component : max concurrent http connection, IIS limits, having many load clients... You load test is invalidated because of this.
I am writing card game using Silverlight and HttpPollingDuplex.
I have 4 seperate http duplex services, which can be called from my game (silverlight client)
1. ChatService
2. AuthService
3. LobbyService
4. GameService
After I host the game under IIS 7.5 I note with Fiddler that Silverlight client do polling requests sequentially, and my application become very slow, because for example for getting message from chat service client have to wait until other services polling will be finished. Than I changed serverPollTimeout for services to finish pollings faster, now my game works faster, but do continues requests to services sequentially. so the question is
Is it possible to create client proxy or configure client to do polling queries parallel in case of more than one polling service? and if not is changing serverPollTimeout good practice in my case? or what will be the best configuration for me?
Creating proxy and calling service methods in separate thread doesn't help :(
Thanks a lot!
Here is my workout if someone has the same problem
There is a limit to how many HTTP connections Silverlight can use in the browser, If all the services live on the same host://name:port, there should be only one onging polling connection to it, no matter how many services are hosted there.
I created sub domains for each service, which solves the problem
Another solutions is set created instance as a static property.
In my application I need to push notifications of real time events from server to clients. The amount of data to pass is very small, mostly and Id. The number of clients listening simultaneously can be around 100 and I may have to publish one notification every 2 - 3 seconds. Both the server and client are built using .Net and WCF.
Given these requirements I have built a set of WCF services which will be run on a load balanced server cluster. The Instance context mode is Per Call and there is no need for sessions etc.
I am currently using BasicHttpBinding. Will TCP binding be better? Does it run on IIS 5 or 6? If not why?
What configuration for serialization can work best?
What are the things I need to do to make sure I get maximum performance?
Edit - Adding more information based on some of the responses -
I host a small WCF service in the client process using manual hosting. The server just calls this service on each client to push the data to all of them.
Firstly have you considered using messaging for what you are trying to achieve?
In answer to will TCP binding work better than BasicHttpBinding- almost certainly yes. If you want to use TCP, you can't use IIS- look into WAS with Windows Server 2008. If you're stuck with Windows Server 2003, then you'll have to host in a windows service instead.
You've made a good choice by choosing per call- this is the preferred instance management mode for creating scalable WCF services.
Edit:
Now you've update your question, I recommend you take a look at IDesign's Pub/Sub framework if you want to stick with WCF. I'd also look at Pub/Sub with MSMQ in WCF and also with "Vanilla" products such as Tibco RV.
If you need pushing data from service to clients you need sessions and you need duplex binding - NetTcpBinding or WSDualHttpBinding. It will not work with BasicHttpBinding because it allows only pulling data (client pools the service for changes). Push data means tha service sends data to clients when needed.
NetTcpBinding always crete session. It can't be hosted in IIS 6 or older. NetTcpBinding is allowed only in Windows Activation Service (WAS) which is extension of IIS 7.x. For older systems you need self hosting = windows service.
Edit:
Based on your description you need Publish-Subscribe message exchange pattern.