We have a quite strange situation on my sight. Under load our WL 10.3.2 server failed to response. We are using RestEasy with HttpClient version 3.1 to coordinate with web service deployed as WAR.
What we have is a calculation process that run on 4 containers based on 4 physical machines and each of them send request to WL during calculation.
Each run we see a messages from HttpClient like this:
[THREAD1] INFO I/O exception (org.apache.commons.httpclient.NoHttpResponseException) caught when processing request: The server OUR_SERVER_NAME failed to respond
[THREAD1] INFO Retrying request
The HttpClient make several requests until get necessary data.
I want to understand why WL can refuse connections. I read about WL thread pool that process http request and found out that WL allocate separate thread to process web request and the numbers of threads is not bounded in default configuration. Also our server is configured Maximum Open Sockets: -1 which means that the number of open sockets is unlimited.
From this thread I'd want to understand where the issue is? Is it on WL side or it's a problem of our business logic? Can you guys help to deeper investigate the situation.
What should I check more in order to understand that our WL server is configured to work with as much requests as we want?
Related
I have a WCF SOAP service that receives too many synchronous requests from other systems
I am having problem when too many request comes at that time IIS Queue will not provide proper result and server memory and CPU usage is gone high and discard request or time out
I did a normal Load test (100 requests with 100 concurrent user) and the IIS started to discard the requests after the maximum queue length reach as well as all the request coming delays to provide the response and Other requests coming in are delayed until the first one either times out, or responds.
Below is server configuration
WCF application code is tested with Resharper tool and there is no object or memory dispose issue
Is there any settings for setup application pool or worker process to manage queue ?
Can i apply web garden in Application ?
Please help me to solve this issue
Thanks in Advance
Using Weblogic 12c, i have a big problem: when calling a rest service using differents clients (java client or using command line like curl) there is no problem.
BUT when the client is in C#, the request is executed severals time (each minutes) by one different thread of the pool so it implies lot of errors in log files because:
The C# client get its response and close the connection, but the others 'duplicated' requests (by threads pools) creates stacks errors because the service can not write a response (there is no client to get the response).
Some precisions:
- There is no Stuck thread in my case.
- Using Tomcat there is no problem
- There is the same problem using new installed Weblogic12c Server (so there is no custom configuration)
- The http headers are the same between C# or others clients
- The same data tests are used to reproduce the problem
check access.log to check how many requests are received by the server, if its more in case of c# then its a problem there not the server.
You can also enable http debug to get more details about the incoming request.
We observed the following behavior on one of the servers hosting a WCF service on IIS 6.0:
The IIS log shows a high value for time-taken (> 100000)
The HTTP status code is 200
sc-win32-status code shows a value of 64
I found out that sc-win32-status code of 64 indicates "The specified network is no longer available"
Initially I suspected that it could be because of limits set on MinFileBytesPerSecond, which sets the minimum throughput rate that HTTP.sys enforces when sending data from the client to the server, and back from the server to the client.
But the value for sc-bytes and cs-bytes indicate that the amount of data is sent is within the range generally observed for the service.
Also note that the WCF service is hosted on four boxes and is load-balanced, but the problem occurs only one of the servers. (but not essentially on the same server). The problem is also intermittent.
Has anybody else encountered this error? Any clues about what could be wrong?
Update
Note: Observation on IIS 7.5 (IIS version does not really matter)
I was able to replicate the issue. The issue occurs if:
1. The WCF service takes a long time to respond
2. The client proxy times out before it receives a response from the server. In this case it leads to TimeoutException on the client.
3. The server keeps waiting for TCP ACK for the client, which it would never receive.
Hence a long timeout (TCP socket timeout (default value: 4 minutes) and sc-win32-status of 64
So essentially it appears that WCF code is taking a long time to respond and the client is timing out, what I observe in IIS log is just a symptom and not a problem.
The behavior you are describing will also occur if you exceed a WCF service's max sessions, calls or instances (depending on how you have your service instancecontext mode configured). If you observe the System.ServiceModel performance counters for %max concurrent sessions and/or %max concurrent calls (again depending on your service's instance context), you may see a correlation with the IIS log entries.
Note that these maxes can be configured in the service throttling behavior.
https://msdn.microsoft.com/en-us/library/vstudio/system.servicemodel.description.servicethrottlingbehavior(v=vs.100).aspx
I saw your question again and wanted to point out that I found a solution for this. It turned out to be this piece of code in the web.config:
<pages smartNavigation="true">
After turning this off I stopped receiving the same time-out errors. See also the answer here
IIS put the services into sleep to save recources.
Copied from here (WCF REST Service goes to sleep after inactivity)
The application pool hosting your service defines Idle Time-out property (advanced settings of app pool in IIS management console) which defaults to 20 minutes. If no request is received by the app pool within idle timeout the worker processes serving the pool is terminated. After receiving a new request the IIS must start the process again, the process must load application domain and all related assemblies, compile .svc file, run the service host and process the request.The solution can be increasing idle time-out but the meaning of this time-out is correct handling of server resources. If the process is not needed it should be stopped. Another ugly workaround is using some ping process (for example cron job or scheduled task on the server) which will regularly ping call some method on the service or page in the same application.
I'm working on a self-hosted WCF application which runs just fine on my PC; however, when I try running it on a VM hosted locally using VMware Player, the service takes some two minutes to return data, whereas the original request took only a few seconds.
The VM is using 2Gb RAM and dual CPU running Windows Server 2008 R2 (on an 8Gb/quad core host running Windows 7).
Looking at the WCF service trace, I have the following log entries (time/description):
15:41:26.771 From: Processing message 1.
15:41:26.771 Activity boundary.
15:41:26.820 Received a message over a channel.
15:41:26.844 ServiceChannel information.
15:41:26.848 Incoming HTTP request to URI 'http://localhost:8000/Sql/Database' matched operation 'GetDatabase'
15:41:26.944 Message Log Trace
15:43:25.775 To: Execute 'MyProject.ISqlService.GetDatabase'
15:43:25.775 Activity boundary.
15:43:25.947 From: Execute 'MyProject.ISqlService.GetDatabase'
15:43:25.947 Activity boundary.
15:43:25.947 Message Log Trace
15:43:26.134 Throwing an exception.
15:43:26.134 RequestContext aborted
15:43:26.134 Activity boundary.
So the two minute delay occurs between receiving the incoming HTTP request and the dispatch to the service implementation. This delays occurs whether the request is the first (thus incurring the usual WCF warm-up penalty) or a subsequent request.
While I appreciate that I'm not going to get bare-metal performance from a VM, I'm still concerned about the dire performance, especially as the client tends to timeout before the end of the two minutes. Is there anything I can do to improve matters? It's making testing very difficult.
Maybe your proc does not support VT-x/AMD-V extension, so virtualization is not hardware-accelerated. Check your hardware using CPU-Z.
My application has 50 service endpoints (such as /mysite/myService.svc). It's hosted in IIS. Intermittently (once every two or three days) a service stops responding. It's never the same service that hangs. While a service is hung, some of the other services work fine and some other are also hung.
All clients (from different computers) get this error:
ServiceModel.CommunicationException
Message: An error occurred while receiving the HTTP response to
https://server/mysite/myservice1.svc.
This could be due to the service endpoint binding not using the HTTP
protocol. This could also be due to an HTTP request context being
aborted by the server (possibly due to the service shutting down).
See server logs for more details.
No exceptions are raised by the server when the client attempts to call the service that is hung. All I have is that error on the client side.
I have to manually recycle the application pool to fix the problem.
Do you know what could be the cause? How can I investigate this issue? I'm willing to take a memory dump of the worker process when a service is hung but I would not know what to search for in the dump.
Update (Aug 13 2009): I have almost ruled out the idea that the server runs out of connections (see comment in Shiraz Bhaiji's answer). I might have a new lead: I log all server-side exceptions in a log file. So in theory, when this occurs on the client, no exceptions are raised on the server; otherwise I'd have proof of that in my logs. But what if an error does occur on the server but is happening at a low level where exceptions are not routed to my exception handling code? I have posted this question about scenarios where low level exceptions cannot be handled. I'll keep you informed of the progress of my investigation.
Sounds like you are running out of connections.
By default WCF has a timeout and therefore holds a connection open for 10 mins.
When you recycle the app pool all connections are closed, and therefore things work again.
To fix it check your code to make sure that you close connections / dispose of proxies.
To resolve this, we set establishSecurityContext to False on the binding.
I have not come across this particular issue but would suggest to turn on tracing/message logging for the WCF service in the config for the service and/or the client app (if you have control over that). I've done this in the last few days for a service that I needed to troubleshoot.
The MSDN link here is a good starting point.
Also see the table in this post for the varying levels of trace detail you can configure. There are several levels which can go from exception only logging to full message details. It is quite quick to set this up in the app.config file.
To parse the log file output use the SvcTraceViewer.exe that comes with the Windows SDK, which if you have it installed should be located in this folder: C:\Program Files\Microsoft SDKs\Windows\v6.0\Bin