Hi!
We launched a new site last week that uses ClearScript to server render a React application. After launch, we get around 2-3 crashes on Access Violation Exception in w3wp.exe a day per web server. The site has around 200 concurrent users on average, with peaks up over a thousand. We use the latest version of ClearScript (5.4.7).
We see that the crash is an Access Violation Exception in v8-x64.dll and we have a few dump files from such crashes, but since we don't have any debugging symbols the stack traces doesn't give us much.
Would you be interested in looking at the crash dumps to help us figure this out? Or if you can help us with debug symbols so we can get more information out of the dumps.
Some information about how we use ClearScript:
1. We create multiple V8Runtime and V8ScriptEngine and keep them in a queue. When a request comes in, we dequeue an engine, run JS and return it back to the queue.
2. Since we don't store any JS globals we reuse the same V8 context for different visitors. But we run CollectGarbage(true) for every 30 execution. We have deployed a change this morning where we call CollectGarbage(false) instead but twice as often. Not because we think it will solve it, but see if the behavior changes.
3. We don't pass any CLR references to V8. The only thing we do is call Engine.Execute with strings of JS code. When we pass data to V8 we do that by either calling Engine.Execute or Engine.Evaluate with strings of JSON.
Any help or pointers are appreciated! We'd be happy to share code with you if you need it.
Comments: Hi! We haven't had any crashes now since sunday, but today we got a new crash right after deploying a new version of the site. So it probably wasn't related to high memory use like we suspect that the previous crashes was (suspect but we're not 100% sure). Here's the stack trace we got from the dump: ``` v8-x64.dll!00007ffb36653a93() Unknown v8-x64.dll!00007ffb366d02fd() Unknown ClearScriptV8-64.dll!00007ffb35d93a3d() Unknown ClearScriptV8-64.dll!00007ffb35d93514() Unknown ClearScriptV8-64.dll!00007ffb35d913ff() Unknown [Managed to Native Transition] ClearScriptV8-64.dll!<Module>.std._Func_class<void>.()(std._Func_class<void>* value) Unknown ClearScriptV8-64.dll!Microsoft.ClearScript.V8.NativeCallbackImpl.Invoke() Unknown ClearScript.dll!Microsoft.ClearScript.Util.MiscHelpers.Try(System.Action action) Unknown ClearScript.dll!Microsoft.ClearScript.Util.NativeCallbackTimer.OnTimer(object state) Unknown mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown mscorlib.dll!System.Threading.TimerQueueTimer.CallCallback() Unknown mscorlib.dll!System.Threading.TimerQueueTimer.Fire() Unknown mscorlib.dll!System.Threading.TimerQueue.FireNextTimers() Unknown [Native to Managed Transition] kernel32.dll!00007ffb659713d2() Unknown ntdll.dll!00007ffb67e454e4() Unknown ``` Is this actionable for you?
We launched a new site last week that uses ClearScript to server render a React application. After launch, we get around 2-3 crashes on Access Violation Exception in w3wp.exe a day per web server. The site has around 200 concurrent users on average, with peaks up over a thousand. We use the latest version of ClearScript (5.4.7).
We see that the crash is an Access Violation Exception in v8-x64.dll and we have a few dump files from such crashes, but since we don't have any debugging symbols the stack traces doesn't give us much.
Would you be interested in looking at the crash dumps to help us figure this out? Or if you can help us with debug symbols so we can get more information out of the dumps.
Some information about how we use ClearScript:
1. We create multiple V8Runtime and V8ScriptEngine and keep them in a queue. When a request comes in, we dequeue an engine, run JS and return it back to the queue.
2. Since we don't store any JS globals we reuse the same V8 context for different visitors. But we run CollectGarbage(true) for every 30 execution. We have deployed a change this morning where we call CollectGarbage(false) instead but twice as often. Not because we think it will solve it, but see if the behavior changes.
3. We don't pass any CLR references to V8. The only thing we do is call Engine.Execute with strings of JS code. When we pass data to V8 we do that by either calling Engine.Execute or Engine.Evaluate with strings of JSON.
Any help or pointers are appreciated! We'd be happy to share code with you if you need it.
Comments: Hi! We haven't had any crashes now since sunday, but today we got a new crash right after deploying a new version of the site. So it probably wasn't related to high memory use like we suspect that the previous crashes was (suspect but we're not 100% sure). Here's the stack trace we got from the dump: ``` v8-x64.dll!00007ffb36653a93() Unknown v8-x64.dll!00007ffb366d02fd() Unknown ClearScriptV8-64.dll!00007ffb35d93a3d() Unknown ClearScriptV8-64.dll!00007ffb35d93514() Unknown ClearScriptV8-64.dll!00007ffb35d913ff() Unknown [Managed to Native Transition] ClearScriptV8-64.dll!<Module>.std._Func_class<void>.()(std._Func_class<void>* value) Unknown ClearScriptV8-64.dll!Microsoft.ClearScript.V8.NativeCallbackImpl.Invoke() Unknown ClearScript.dll!Microsoft.ClearScript.Util.MiscHelpers.Try(System.Action action) Unknown ClearScript.dll!Microsoft.ClearScript.Util.NativeCallbackTimer.OnTimer(object state) Unknown mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown mscorlib.dll!System.Threading.TimerQueueTimer.CallCallback() Unknown mscorlib.dll!System.Threading.TimerQueueTimer.Fire() Unknown mscorlib.dll!System.Threading.TimerQueue.FireNextTimers() Unknown [Native to Managed Transition] kernel32.dll!00007ffb659713d2() Unknown ntdll.dll!00007ffb67e454e4() Unknown ``` Is this actionable for you?