A Firefox instance is running and we write this in the console:
$ firefox www.gnu.org
Then the link is is opened in an already existing window. Then immediately, the Firefox-process that we called in the console stops. The IPC here occurs between the process that maintains the already opened window, and the process that was started from the console by us.
We choose one from Named Pipes, Message Passing and Shared Memory. Which one is used in this situation?
Thank you.
Related
So we are doing distributed testing of our web-app using JMeter. For that you need to have the jmeter-server.bat file running in background as it acts as sort of a listener. The problem arises when one of the slave machine out of 4 restarts due to the load and the test is effectively stuck right there as the master machine expects some output from the 4th machine. Currently the automation is done via ansible-playbooks which are called in Jenkins. There are more or less 15 tests that are downstream to one another. So even if one test is stuck, the time is wasted until someone check on the machines.
Things I've tried so far:
I've tried using the Windows Task Scheduler and kept the jmeter-server.bat to run without any user loggin in, but it starts the bat file in background which in-turn spawns all the child processes in the background as well i.e. starts Selenium Chrome in headless mode.
I've tried adding the jmeter-server.bat in startup and configuring the system to AutoLogon without any password to trigger a session which will call the startup file. But unfortunately the idea was scrapped by IT for being insecure.
Tried using the ansible playbook by using the win_command but it again gets stuck as the batch file never returns anything.
Created a service as well for the bat file, but again the child processes started in background.
The problem arises when one of the slave machine out of 4 restarts due to the load
Instead of trying to work around the issue I would rather recommend finding the root cause and fixing it.
Make sure to follow JMeter Best Practices
Configure Java to take heap dump on failure
Inspect Windows PerfMon and operating system/application logs
Check presence of .hprof files in the "bin" folder of your JMeter installation and see what do they say
In general using Selenium for conducting the load is not recommended, I would rather suggest using JMeter's HTTP Request samplers for that, given you properly configure JMeter to behave like a real browser from the system under test perspective there won't be any difference whether the load comes from HTTP Request samplers or from the real browser.
The same states documentation on the WebDriver Sampler
Note: It is NOT the intention of this project to replace the HTTP Samplers included in JMeter. Rather it is meant to compliment them by measuring the end user load time.
I created a browser instance using Cefsharp library. In the task manager I see only the below processes and not embedded browser webview.
But, when I created browser instance using the Microsoft Edge WebView2, I see that process as well present. Since, both are chromium based I was thinking same set of processes to be present.
Any explanation should greatly be helpful.
Both CefSharp and MS Edge WebView2 are based on Chromium, so both libraries use multi-process architecture.
The msedgewebview2.exe process with the --embedded-browser-view=1 command line parameter you see when running MS Edge WebView2 represents a main Chromium process. It doesn't have --type=....
In CefSharp you don't see the main Chromium process, because CefSharp initializes Chromium inside a .NET application which might have absolutely different name.
So, the behavior you see is expected and there's nothing strange or unusual if you know how it works inside ;)
In this Eclipse RCP application I am making, when a new launch is made, it checks some details of the already running launches which are retrieved by DebugPlugin.getDefault().getLaunchManager().getLaunches().
If it has certain details of its configuration the same as any of the running launches, it should stop. Currently so far, so good.
The Issue
What happens when I edit a LaunchConfiguration while launches of its type are still ongoing? Will that change the attributes of all the running launches' launch configurations? (I am talking about what is retrieved by: ILaunch.getLaunchConfiguration() )
EDIT: More details: in this case it is a hardware connection, and the hardware can only receive one ongoing concurrent connection. If the launch configuration changes, and we check all of the running launches' configurations, we will be unable to check if we're launching for the same hardware twice
When I call ILaunch.getLaunchConfiguration().getAttribute(String,String) it retrieves the new value that has been changed DURING the launch.
So, yes, if an ILaunchConfiguration during an active ILaunch has some attributes changed, if there is no deep copy made in the ILaunch, the changes will reflect on the running ILaunch. Ugh.
I am looking for a way to monitor the state of one of my applications on OS X. There's a number of components that I need to monitor such as the status of various communication channels. If they go down, the monitoring process should be able to warn the user both on screen and via a push notification.
XPC services look promising, but if the app crashes, I presume this will take out the service as well, or am I mistaken?
My preferred solution is something which would also monitor for unexpected termination, and restart the app if it happens.
What is the best way to do this?
I think monitoring communication channels, etc. must be done by the each specific components (processes). And if the unexpected error occur that component should exit immediately to ensure proper cleanup.
For processe monitoring, below Apple Technical Q&A document will be really helpful:
Technical Note TN2050: Observing Process Lifetimes Without Polling
You could write an app which starts your main application as a child process, and waits for it to exit. It could check the exit code, and then react according to your needs.
This approach is explained here: https://stackoverflow.com/a/78095/785411
To fork() some monitoring process to run your main application as a child process, this is explained here: https://stackoverflow.com/a/4327062/785411
I think you could possibly make use of the built in facilities Launchd and CrashReporter to achieve your requirements.
Launchd is the OS X system supervisor intended for launching and monitoring background processes, and would be typically used to run XPC services. Launchd agents can react to various system events, and can be configured to restart processes in the event of them crashing ( specified via the KeepAlive/SuccessfulExit key in the property list)
Launchd can be set to react to various system events as launch event, including monitoring files and directories, scheduled times, or listening to network connections.
CrashReporter is the OS X system facility that catches and logs all process crashes. It logs through the AppleSystemLogger facility and can be accessed with the syslog tools as documented in the linked TechNote. On Mountain Lion, user process crash reports end up in ~/Library/DiagnosticReports/ , with a crashlog and plist file pair created per crash event.
I think you could use these features in a couple of ways to achieve your requirement, if launchd is responsible for running the xpc services, it can take reponsibility for restarting them on crash events, and they can be dissociated from any app crashes.
You could write a launchd agent that responds to for crash events by montioring the crash report directory (e.g. using the QueueDirectories property) for new logs and re-launches your applicaton, or presents notifications.
If each process runs in its own thread you could run a watchdog program that monitors whether the threads are alive. A script that runs ps in a loop and parses the output could do it.
You can see the various options here. See for example -C to select by command name, and -m to show all threads.
I have couple of machines on which I wish to schedule exceutions. I need to access these machines remotely for exceution. Whenever I start exceution from these machines and minimize the session my script fails. So just curious to know whether QTP scripts can be executed while keeping sessions minimized. If yes what changes needs to be made in script. Thanks.
When you minimize this window, the operating system switches the remote session to a GUI-less mode and does not display windows and controls. As a result, the tests are unable to interact with the tested application’s GUI as the GUI doesn’t actually exist in this case.
You need to change Registry keys on your computer (that is, the computer from which you connect to a remote QTP workstation). Here is a step-by-step description:
Close Remote Desktop sessions opened on your computer.
Click Start and select Run. In the Run dialog box, type regedit and press Enter. Registry Editor starts
Locate any of the following Registry keys:
HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\
(if you want to change the RDC settings for your user account)
-- or --
HKEY_LOCAL_MACHINE\Software\Microsoft\Terminal Server Client\
(if you want to change the RDC settings for all accounts)
Create a new DWORD value in this key named RemoteDesktop_SuppressWhenMinimized. Specify 2 as the value data.
That’s all. Now minimizing the Remote Desktop Connection window on your computer will not affect the remote computer’s GUI and the GUI will still be available to your automated GUI tests.
This was taken from: http://blog.smartbear.com/post/10-10-11/testcomplete-tip-running-tests-in-minimized-remote-desktop-windows/
The problem you're facing is that if you minimize your display the remove machine knows that it doesn't have a display and ignores any questions about control locations and requests to move the mouse. In some cases QTP runs tests using device replay which means that the test will fail.
To work around this you need to have the remote machine think that it still has someone attached to it. One way is (obviously) to not minimize or close the remote desktop session. Another way is to use a remote access program that doesn't inform the remote machine when it's minimized a free example of such program is VNC, if I remember correctly you can even close the VNC session (not just minimize it) and the test will still run successfully.