I'm developing an iOS framework and I like to be able to log data for posible crashes. I don't like to use external logging framework like Fabric to avoid conflicts with the main app that uses the framework. Which should be the best approach to do that. Can I use the dsym files in any way? Thanks a lot.
If I correctly understand what you're trying to achieve; you'd like to get crash reports from apps which link against your framework however only if they occurred directly as a result of the code provided by the framework?
This would be fairly difficult to achieve, as crashes occur at the process level rather than your framework having its own isolated 'section' or subprocess.
You could potentially catch some Objective-C exceptions by writing code to detect and prevent them from resulting in crashes, however major faults such as EXC_BAD_ACCESS would not be 'detectable' without processing the app's crash logs.
If you decide to analyse the crash logs themselves (e.g. when the app next launches), this would require the dSYM of the specific application and build to symbolicate the crash. Once you've symbolicated the crash, you'd then need some logic to determine if the crash was likely due to your framework or not. If you receive crash reports from multiple apps, you'd need to ensure that you use the correct dSYM for each log, as this will very likely be different for each one.
Related
We have used several 3rd party crash logs in past like crittercism, Flurry, crashlytics etc. There're some crash logs in which we are not able to get exact crash point. So, do we have any tool available which provides exact crash point ?
OR which is best 3rd party crash log tools in iOS ?
Depending on the type of crash, stack traces may not contain any of your apps code, which is perfectly fine.
Especially when dealing with memory issues, the crash will happen somewhere completely different than where the bug in your application is. You will have to check for the Exception Type information in the crash log and then go from there.
The following documents can help you understand crash reports better:
https://developer.apple.com/library/ios/technotes/tn2151/_index.html
http://www.raywenderlich.com/23704/demystifying-ios-application-crash-logs
You should also use the tools Xcode provides to make sure there are no easy to detect bugs by using the Instruments Leaks tool, use the Analyze build feature in Xcode, or the Address Sanitizer check in Xcode 7.
With a custom crash reporting system (like the ones specialized at Ask the user to send crash log after crash on iPhone) to send the log, the app needs to restart. Why? Isn't there a possibility to send it during the custom exception handling? Or is there a crash reporting system that doesn't need to restart the app?
When a crash occurs the app is in a highly unstable state. So a crash reporting library can not do anything since even allocating memory at crash time may cause way more damage. So crash reporting SDKs can only use so-call async-safe C methods to collect all crash data. Any Objective-C code can not be processed either and also the iOS networking stack can not be used.
Please also note that exceptions are just one example of app crashes in Objective-C, there are also crashes triggered by low-level BSD signals. Both types mean that the app is in a highly unsafe and unstable state and as little code as possible should be invoked at crash time.
So this would require a rewrite of most of the networking frameworks to be able to send data out at crash time, and this may even not be possible to do in a safe way. That is why all proper crash reporting SDKs don't do anything like that.
In addition, on iOS it is not possible to create another process which could send the data in the background, so the only safe and possible solution is to send data the next time the app starts.
Now this has another conclusion that crashes that happen early on app startup might never be sent since the app is crashing before or while it sends. Some SDKs provide mechanisms to handle that scenario which most likely requires changes in your app startup code.
Since you app crashed there is no process running any more that you app controls, thus you can not start a new process to send the report.
Any code in the crash handler only has limited time to save what ever made you app crash before iOS kill whole app and removes it from memory.
When you restart you app the crash reporter formats the crash report and sends it. This can only be down when the when you app is active.
If there is a crash for an application, can I capture the crash logs and send it to a server right after the crash. I guess my question really is if the app crashed can I use the network api to send some data to the server.
Lots of services out there to do this... HockeyApp & TestFlight spring to mind.
Update: HockeyApp has just released a Mac Application 'HockeyCoach' to allow you to view crash reports within a native App, with awesome functionality like viewing the source code referenced in the crash log etc...
I highly reccomend you check it out: http://hockeyapp.net/releases/hockeycoach/
Yes, there are several solutions that provide this functionality. One of them that I'm intimately familiar with (and works very well) is Apigee's Mobile Analytics (http://apigee.com/docs/enterprise/content/analyze_apps).
One of the important points for dealing with crash logs is to save a copy of your .dSYM. This is needed to symbolicate the crash log.
Try using Crashlytics. Extremely simple to incorporate into app and is completely free.
That probably sounds a lot worse than it is, but here's my question.
I am dealing with a crash on an actual device, that one of my tester's is using. At the moment, there is no way to discover what is causing the crash. I can not reproduce it on the simulator. However, on the simulator when something crashes I get log info about it in the output window. But I don't want to keep testing with the device connected.
Is it possible to log crash exceptions, etc into a file when things crash. I know certain apps can do it, but I am not sure how?
Any info would be appreciated.
There are generally two ways to do that:
Someone get the tester to send you the crash reports, that iOS created on the device. This is usually too tricky for end users, so the next suggestion works better. That's also why I am not describing how to do that :) But you'll find plenty of documentations on that process.
Integrate a crash reporting library, that catches the crashes and allows you to receive them in various ways. You should not implement your own global crash exception handler, things are just too complex to do it right (even though other people will tell you otherwise). Also crashes caused by exceptions are only one type of crashes.
There are multiple open source libraries out there, the safest one to use is anything based on PLCrashReporter. Most others use private or undocumented iOS APIs, or are not async-safe, which basically means those can destroy app data or make the crash even worse. See this blog post about the topic: http://landonf.bikemonkey.org/code/crashreporting/Reliable_Crash_Reporting_1.1.20130119.html
The following linked answer shows some of the available options on how to add logging to your app and also various options on how to receive crash reports for test version and also once the app is released: Including custom data into iOS crash dumps
If you're open to using a third party service, I use https://www.crashlytics.com. Makes debugging crashes from user devices painless.
Hello Stack Overflow !
A simple question for you : is it possible to embed custom error data into automatically generated iOS crash dumps I get from my users when my app crashed on their device ?
For example : My SQlite database won't operate for some reason (say, the database file is corrupted).. I cannot recover from this error, so I throw an exception, and embed in the exception the detailed sqlite error message. The problem is, the crash dump of the application won't contain the exception message, so it's not easy to know under which conditions the application crashed.
Does anyone know a way to put things into the crash dump report ? Or do you have any other recommended way of reporting production crashes to the developper ?
Thanks !
No, you cannot ad your own data into the crash reports. It is also not possible to access iOS generated crash reports automatically because of the sandbox.
So my suggestion is as follows:
For logging your own data, use Cocoalumberjack. It is much faster than NSLog or other logging frameworks out there and has an option to log your messages into a file. Now when an exception occurs, or whenever else you want to, log that into a file. But if your app crashes right at a point where you add something into a log file, it most likely will be missing, since the app crashed the very same moment.
So its rather impossible to safely catch the exact SQL statement. But the crash report should give you enough information to understand what is happening, with the addition to what you logged of being done before. E.g. you could log the search string used in the SQL way before the SQL is being executed.
In general try not to log too much.
For catching crash report you should nothing else than a solution based on the open source framework PLCrashReporter, which can safely catch crashes, also when you app is already in the app store! Exception catching is not recommended, check this article to see why!
iTunes Connect offers you to view some crash reports too, but it takes up to 2 weeks to see some, but by far not all as e.g. pointed out by the Camera+ developers. So you better use your own solution.
PLCrashReporter will send you standard apple formatted crash reports, ready for symbolication, so you know where the crash happens in your code, including line numbers.
Some solutions based on PLCrashReporter are:
QuincyKit: Open Source client + php server, basic crash grouping, symbolication can be automated from your mac (I am the developer of this)
HockeyApp: Paid service, uses QuincyKit client, advanced crash grouping, symbolication fully done on the server (I am on of the developers of this)
Bugsense: Free service, symbolication announced as premium feature
AppBlade: Paid service, symbolication unknown
Crashlytics: Private beta, unknown features, their solution seems to be based on PLCrashReporter
The proposed solutions either allow sending the data automatically on the next startup or by asking the user if he/she agrees to send.
Disclaimer-as-per-the-faq: I am a developer for AppBlade.
AppBlade allows you to send custom parameters along with symbolicated crash reports as of December 2012.
Check it out! http://blog.appblade.com/news/2012/12/appblade-sdk-update-sessions-and-queues/