rushikeshpatil12/crashrecovery

Demonostration of recover and restart from a crash/hang situation.

CrashRecovery

CrashRecovers demonstrates recovery mechanism from crashes/hangs using a simple do-nothing app. This app stays alive, recovers and restarts from a crash or a hang situation. In case of crashes/hangs, it creates and saves the application state(memory dump) that can be used for later troubleshooting.

Platforms:

• Windows Vista & Windows server 2008.
• Windows 7 & Windows server 2008 R2.
• Windows 8 & Windows server 2012.
• Windows 8.1 & Windows server 2012 R2.
• Windows 10 & Windows server 2016.
• Both x86 and x64 are supported.

Design:

• CrashRecovery.exe designed to work on windows platforms.
• It handles the WOW64 redirections for 32-bit(esp. registry).
• CrashRecovery uses WER(Windows Error Reporting) APIs to get crash notification, recovery callbacks, system event callbacks, crashdump, etc.
• WER APIs requires app to be running for, at least, 60 seconds to avoid cyclic restart.
• Crashdump: Only the last crash dump is saved to preserve the diskspace.

Alternate design considerations:

• Another approach is to create two instances of the executable. One instance will run the application while other monitors the first app.
• On crash monitor app can save the crash dump and restart the app if needed.
• Platform independent solution could prefer this approach.

Usage:

• Run CrashRecovery.exe with admin command prompt(App uses registry & WER settings thus needs admin rights.)
• App keeps crashing every 61 seconds, collecting crashdump.
• Press Ctr+C to exit.
• By default crashdump is created in the module directory with name similar to CrashRecovery.exe.11748.dmp.

Note:

• Settings such as minidump/fulldump are configurable in Settings class(Settings.h).
• Older versions of windows show the crash notification(UI) by default. If required this can be disabled with registry setting(HKEY_CURRENT_USER\Software\ Microsoft\Windows\Windows Error Reporting\DontShowUI = 1).

Testing:

Testing is done on windows 7 & windows 10 x64 and x86 platforms.

Assumption:

1.Windows WER would be enabled and active for this application.

• It's possible that WER(Windows error reporting) can be replaced with some other Error handling tool.

TODO:

• Improvement in logging framework.