I have wrote two multi-threaded windows service.
Both connects to the same database.
Both are having a WCF service reference.
Say Service "A" is for getting the data from WCF service and writes it down to the connected database.
Say Service "B" is for getting the data from connected database and send it to WCF service.
Both starts perfectly and keeps running perfectly for days (though, i have not noted the frequency) But then something occurs and Service "A" status stays on "Running" but it isnt actually running. (I can say this because I am writing log file whenever the service perform something). However Service "B" has never got any problem.
For the resolution, I need to force kill the service using Command Prompt and then restart it. I have checked the event logs but nothing found. RAM is also available so memory is also not an issue.
Related
I have this Windows Service (using SqlDependency) that sends me an e-mail everytime it is started and everytime a new row is inserted on my Sales table (the database has Service Broker enabled).
I also write a log file to register when the service is started, the data is inserted to the table, if the e-mail was successfully sent and when the service is stoped.
When I started the service manually, it worked just fine.
Then I turned my PC off and on again and inserted data on my table
in the database, but nothing happened (no e-mail sent and no
register in my log file).
I restarted the service manually and it worked fine again.
Turned the PC off and on again and nothing heppened again.
I made some research and changed the initialization type to Automatic
and tried again. And nothing happened again.
I changed the initialization type to Automatic Delayed and tried
again. But it didn't work too, even 1 hour after I turned the PC on.
Now I manually restarted the service and the log file registered that
the service stoped and started, I received the email that the service
started and, after I inserted data in my database table, both log
register and email message worked just fine.
Everytime it didn't work, I checked the services manager in Windows and it was marked as "Running".
I don't know if I need to configure something different in my code or in my service properties.
Has anybody ever had this issue?
EDIT
I modified my service and included a timer, so every minute passed it writes the time in my log text file. After I restarted my PC, the log file continued to register the time every minute, but did not register the insert I made in my database table.
My guess is that the service might be losing the database connection when the PC is restarted, so the SqlDependency cannot detect the changes. Does it make any sense?
Your service depends on SQL Server, but your service is probably starting before SQL Server has been started, or finished starting. This may be causing your SqlDependency to fail.
You can mark your service as being dependent on SQL Server, which means:
Windows won't attempt to start your service until SQL Server has started and is ready, and
Starting your service will cause Windows to start SQL Server before it starts your service
This can be achieved on the command-line with the sc command (which will need to be run at an administrative command prompt). If your SQL Server instance is named MSSQLSERVER and your service is named MyService the command would look like this:
sc config MyService depend= MSSQLSERVER
Note: The space after = and before MSSQLSERVER matters. The detailed syntax can be found on learn.microsoft.com.
Once this command has run successfully, this is what you'll see when looking at the properties of your service in Control Panel > Administrative Tools > Services:
I'm currently working on a WCF service which holds and processes all the data for an application, while a MySql database is used for persistence. The service currently works as a singleton (InstanceContextMode.Single) and supports multiple concurrent calls (ConcurrencyMode.Multiple). I'm not really sure what version of IIS the service is hosted in, but I believe it is IIS 7.5.
The problem is that there are some situations where if an exception occurs (eg.: while releasing ReaderWriterLockSlim locks), the service will be in a unreliable state and data may get corrupted (and written into the database) if users keep calling the service.
Currently I know of two ways of preventing users from calling the service: either closing the InstanceContext object (through OperationContext.Current) or raising an exception in IDispatchMessageInspector.AfterReceiveRequest if the service is in a faulted state. The problem with both of these two ways is that they make the service unavailable until I restart the server/application pool (which I can't, see note below) or re-deploy the service.
Important note: Although I have Full-Trust, the service is currently hosted on a shared server, so I can't restart the server or the entire application pool (if that is possible) because that would restart other people's services as well.
Update:
I tried unloading the AppDomain as #usr suggested, but that doesn't work as well: after unloading it, an exception is raised for every call to the service.
Currently I'm trying to find out what WCF/IIS uses as a condition to decide if the service should be created again. I noticed that in the code generated for the client checks if there is any channel available to communicate with the service; if there isn't, a new one is created. Thus, I tried to close all channels in the service: I tried closing OperationContext.Current.InstanceContext.OutgoingChannels, OperationContext.Current.InstanceContext.IncomingChannels, OperationContext.Current.Channel, and many other properties with "Channel" in their name, all of them with no success.
The way to warm-up anything in IIS prior to version 7.5 is using scheduled console application to ping your web site / services and warm them up. It's not a good fix but it works, it is easy and I saw it on every project which had to deal with this requirement.
Or If you are using IIS 7.5 then
You can use Windows Server AppFabric, it has Auto Stat feature to keep the service always on. But you need to be on IIS 7.5 to install App Fabric.
HI I have a solution with a couple of projects.
One of them is a self-hosted WCF Data service.
This service is running fine on his own, but I want to start it from my main method.
This way I can control wether is should start or stop.
Why I need to do this is that I can run my main method and let the service start, but when the program exits, the service is still running.
Anybody know how to fix my problem?
--EDIT--
This service thing is new to me. So I'm not even sure it's possible.
Let's say I have 2 projects. One contains my main method and the other is a WCF Service Application project.
I want to be able to stop my service from within the main project whenever I want to.
--EDIT2--
I am creating a system that can provide data to clients through an API (WCF Data services). When my system starts, I want to start the service. When my system shuts down, my service have to stop existing or at least providing data.
I have developed a Windows Service, that must start automatically during Windows startup. This service connects to an Oracle db, so I made my service dependent on Oracle Services by sc command line utility:
sc config MyService depend= OracleServiceXE/OracleXETNSListener
So far so good, dependency was set succesfully. But when Windows starting, my service could not start, I get the following (Oracle) error message: "ORA-12528: TNS:listener: all appropriate instances are blocking new connections".
As I think, the Oracle services are started when my service starts, but they are not 'fully initialized'. After some seconds I can start my service from service consol without any problem.
So, how can I start automatically my service at Windows Startup which is dependent on an Oracle DB connection?
My service was developed in C# on .Net 4 platform, in VS 2010 environment.
Pls. help me, it is a really important task form me!
Remember, the code for your service's startup should do as little as possible. In other words, don't have your service startup check for availability of the Oracle server, or indeed do anything. Have your service do the following:
Log the fact that it's started
Load any applicable configuration from config files/registry/etc
Spin-up a thread that will try and "startup" the service properly every N seconds, and will repeat M times until it gives up. Have N and M configurable from your config file/registry
Have the thread "try" to connect to the applicable Oracle server and if it fails, go to sleep for N seconds, and do this M times. If it succeeds it can then start doing the "meat" of what it's supposed to.
Ironically, it's probably the fact that the Oracle service does something similar to what I've proposed you do that's causing you the problem. By returning "Yes, I've started" quickly back to Windows when it's started, it allows your service to then be loaded, even though Oracle is still busy spinning stuff up. Ideally in this scenario rather than rejecting your requests, Oracle should enqueue them for processing when it is ready.
I've written a windows service in C# that converts wav files into mp3 and then stores them on a remote server. On my development rig (OS: WinXP SP3) the service starts up fine and runs the way it's supposed to.
When I installed it the production machine (OS: WinServer 2000), upon starting the service it fails to start in a timely fashion, and remains in a constant "Starting" status. The program is clearly working though since the files are being converted and transferred.
My hunch is that the problem is in the timer component, I think that on the Windows 2000 Server machine, the timer may be causing the system to register the program as "Starting".
Is there something I'm missing about Windows Server 2000?
I'm not familiar with writing services in .NET, but in general, the thread that is used to start the service and report its initial status should not be the same thread that performs the actual work. The service should spawn a worker thread so the entry point can return status to the SCM quickly.