我正在调查一款 Web 应用程序,它的内存使用高达 10GB。我使用 Windbg 分析了一个内存转储文件。
以下是 !dumpheap -stat 命令输出的底部内容:
所以,几乎有4000万个`System.Runtime.Caching.ExpiresBucket`实例,总共使用了近4GB的内存。在最占用内存的类中,`System.Runtime.Caching`类出现得相当频繁。
我随机选择了一个`System.Runtime.Caching.ExpiresBucket`类的实例,并对其进行了!gcroot操作。这需要很长时间(可能30分钟)才能生成1个线程……可能还有更多,但我在此时中断了操作。
引用链超过150万行!但我可以在此处展示重要部分:
在
是什么导致了内存泄漏?我应该如何识别出有问题的类或代码?在 gcroot 输出中没有任何对我们自己代码的引用,所以它是由我们正在使用的安装库中的错误引起的吗?还是因为 Ninject 的一个 bug?我们正在使用 v3.2.2(不是最新版本,我知道)。
以下是 !dumpheap -stat 命令输出的底部内容:
00007ff9545df5d0 166523 13321840 System.Runtime.Caching.MemoryCache
00007ff9545df4a0 166523 14654024 System.Runtime.Caching.CacheMemoryMonitor
00007ff9545de990 166523 14654024 System.Runtime.Caching.SRef[]
00007ff9545dcef0 166523 14654024 System.Runtime.Caching.GCHandleRef`1[[System.Runtime.Caching.MemoryCacheStore, System.Runtime.Caching]][]
00007ff9545dfb28 166523 19982760 System.Runtime.Caching.MemoryCacheStatistics
00007ff956778510 333059 21315680 System.Int64[]
00007ff95679c988 41597 31250111 System.Byte[]
00007ff9545e08c8 1332184 31972416 System.Runtime.Caching.MemoryCacheEqualityComparer
00007ff9545dfe48 1332184 31972416 System.Runtime.Caching.SRef
00007ff956780ff0 1332200 31972800 System.SizedReference
00007ff956724620 1498777 35970648 System.Threading.TimerHolder
00007ff95677fb30 1536170 36868080 System.Runtime.Remoting.Messaging.CallContextSecurityData
00007ff956796f28 1606960 38567040 System.Object
00007ff9545df810 1332184 42629888 System.Runtime.Caching.GCHandleRef`1[[System.Runtime.Caching.MemoryCacheStore, System.Runtime.Caching]]
00007ff9545dda38 1332184 42629888 System.Runtime.Caching.UsageBucket[]
00007ff9567ae930 1332268 42632576 Microsoft.Win32.SafeHandles.SafeWaitHandle
00007ff9545df968 1498707 47958624 System.Runtime.Caching.GCHandleRef`1[[System.Threading.Timer, mscorlib]]
00007ff9567adbf8 1498777 47960864 System.Threading.Timer
00007ff9545dff50 1332184 53287360 System.Runtime.Caching.CacheUsage
00007ff94986ead8 1536137 61445480 System.Web.Hosting.AspNetHostExecutionContextManager+AspNetHostExecutionContext
00007ff9567a2838 1332210 63946080 System.Threading.ManualResetEvent
00007ff956796948 293525 66384986 System.String
00007ff9545dfef0 1332184 74602304 System.Runtime.Caching.CacheExpires
00007ff9567add20 1498760 95920640 System.Threading.TimerCallback
00007ff9545dfa90 1332184 106574720 System.Runtime.Caching.MemoryCacheStore
00007ff95679b3b0 1333289 106663120 System.Collections.Hashtable
00007ff95678f138 1536171 110604312 System.Runtime.Remoting.Messaging.LogicalCallContext
00007ff9545dffb0 1332184 127889664 System.Runtime.Caching.UsageBucket
00007ff95679d1e0 1333292 128664768 System.Collections.Hashtable+bucket[]
00007ff9567245c0 1498777 131892376 System.Threading.TimerQueueTimer
00007ff9567aec48 1536255 135190440 System.Threading.ExecutionContext
00007ff9545dcf78 1332184 351696576 System.Runtime.Caching.ExpiresBucket[]
000000f82c79d9f0 473339 385303992 Free
00007ff956799220 40309535 1617342672 System.Int32[]
00007ff9545e0468 39965520 3836689920 System.Runtime.Caching.ExpiresBucket
所以,几乎有4000万个`System.Runtime.Caching.ExpiresBucket`实例,总共使用了近4GB的内存。在最占用内存的类中,`System.Runtime.Caching`类出现得相当频繁。
我随机选择了一个`System.Runtime.Caching.ExpiresBucket`类的实例,并对其进行了!gcroot操作。这需要很长时间(可能30分钟)才能生成1个线程……可能还有更多,但我在此时中断了操作。
引用链超过150万行!但我可以在此处展示重要部分:
0:000> !gcroot 000000f82dd4bc28
Thread 1964:
000000fcbdbce6a0 00007ff8f9bbe388 Microsoft.AspNet.SignalR.SqlServer.ObservableDbOperation.ExecuteReaderWithUpdates(System.Action`2<System.Data.IDataRecord,Microsoft.AspNet.SignalR.SqlServer.DbOperation>)
rbp-58: 000000fcbdbce6e8
-> 000000fa2d1f26a0 Microsoft.AspNet.SignalR.SqlServer.ObservableDbOperation+<>c__DisplayClass1e
-> 000000fa2d1f2110 Microsoft.AspNet.SignalR.SqlServer.ObservableDbOperation
-> 000000fa2d1f24d0 System.Action
-> 000000fa2d1f24a8 System.Object[]
-> 000000fa2d1f2468 System.Action
-> 000000fa2d1f1008 Microsoft.AspNet.SignalR.SqlServer.SqlReceiver
-> 000000fa2d1f1330 System.Action
-> 000000fa2d1f1308 System.Object[]
-> 000000fa2d1f12c8 System.Action
-> 000000fa2d1efb70 Microsoft.AspNet.SignalR.SqlServer.SqlStream
-> 000000fa2d1f1528 System.Action
-> 000000fa2d1f1500 System.Object[]
-> 000000fa2d1f14c0 System.Action
-> 000000fa2d1efb20 Microsoft.AspNet.SignalR.SqlServer.SqlMessageBus+<>c__DisplayClass3
-> 000000f92d0b84e0 Microsoft.AspNet.SignalR.SqlServer.SqlMessageBus
-> 000000f92d0b9568 System.Threading.Timer
-> 000000f92d0b96d8 System.Threading.TimerHolder
-> 000000f92d0b95a0 System.Threading.TimerQueueTimer
[... about 100 lines of the same TimerQueueTimer line above, but different memory addresses each time]
-> 000000f92cf1be68 System.Threading.TimerQueueTimer
-> 000000f92cf1be08 System.Threading.TimerCallback
-> 000000f92cf1bb48 System.Web.RequestTimeoutManager
-> 000000f92cf1bb80 System.Web.Util.DoubleLinkList[]
-> 000000f92cf1bc00 System.Web.Util.DoubleLinkList
-> 000000fb61323860 System.Web.RequestTimeoutManager+RequestTimeoutEntry
-> 000000fb6131fd38 System.Web.HttpContext
-> 000000fbe682a480 ASP.global_asax
-> 000000fbe682ac00 System.Web.HttpModuleCollection
-> 000000fbe682ac60 System.Collections.ArrayList
-> 000000fbe682b598 System.Object[]
-> 000000fbe682b018 System.Collections.Specialized.NameObjectCollectionBase+NameObjectEntry
-> 000000fbe682b000 System.Web.Routing.UrlRoutingModule
-> 000000faacec1f40 System.Web.Routing.RouteCollection
-> 000000faacec2030 System.Collections.Generic.List`1[[System.Web.Routing.RouteBase, System.Web]]
-> 000000fa2cfe4d80 System.Web.Routing.RouteBase[]
-> 000000f9acf14cd8 System.Web.Http.WebHost.Routing.HttpWebRoute
-> 000000f9acf149f8 System.Web.Http.Routing.RouteCollectionRoute
-> 000000f9acf1f4f0 System.Web.Http.Routing.SubRouteCollection
-> 000000f9acf1f510 System.Collections.Generic.List`1[[System.Web.Http.Routing.IHttpRoute, System.Web.Http]]
-> 000000fa2cf8f310 System.Web.Http.Routing.IHttpRoute[]
-> 000000fa2ceff770 System.Web.Http.Routing.HttpRoute
-> 000000fa2ceff678 System.Web.Http.Routing.HttpRouteValueDictionary
-> 000000fa2ceff6f0 System.Collections.Generic.Dictionary`2+Entry[[System.String, mscorlib],[System.Object, mscorlib]][]
-> 000000fa2cef9e78 System.Web.Http.Controllers.HttpActionDescriptor[]
-> 000000fa2cef7898 System.Web.Http.Controllers.ReflectedHttpActionDescriptor
-> 000000f9aced4608 System.Web.Http.HttpConfiguration
-> 000000f9aced4db0 System.Net.Http.Formatting.MediaTypeFormatterCollection
-> 000000f9aced6f40 System.Collections.Generic.List`1[[System.Net.Http.Formatting.MediaTypeFormatter, System.Net.Http.Formatting]]
-> 000000f9aced6f80 System.Net.Http.Formatting.MediaTypeFormatter[]
-> 000000f9aced4df8 System.Net.Http.Formatting.JsonMediaTypeFormatter
-> 000000f9acf1f448 System.Web.Http.Validation.ModelValidationRequiredMemberSelector
-> 000000f9acf1f468 System.Collections.Generic.List`1[[System.Web.Http.Validation.ModelValidatorProvider, System.Web.Http]]
-> 000000f9acf1f490 System.Web.Http.Validation.ModelValidatorProvider[]
-> 000000f9acf1db40 Ninject.Web.WebApi.Validation.NinjectDefaultModelValidatorProvider
-> 000000faaceca438 Ninject.StandardKernel
-> 000000faaceca498 Ninject.Components.ComponentContainer
-> 000000faaceca538 System.Collections.Generic.Dictionary`2[[System.Type, mscorlib],[Ninject.Components.INinjectComponent, Ninject]]
-> 000000f9acece000 System.Collections.Generic.Dictionary`2+Entry[[System.Type, mscorlib],[Ninject.Components.INinjectComponent, Ninject]][]
-> 000000f9acecdac8 Ninject.Activation.Caching.GarbageCollectionCachePruner
-> 000000f9acecdcb8 System.Threading.Timer
-> 000000f9acecdd30 System.Threading.TimerHolder
-> 000000f9acecdcd8 System.Threading.TimerQueueTimer
[... just under 1.5 million lines of the same TimerQueueTimer line above, but different memory addresses each time]
-> 000000f82dd4c028 System.Threading.TimerQueueTimer
-> 000000f82dd4bfc8 System.Threading.TimerCallback
-> 000000f82dd4ada0 System.Runtime.Caching.CacheExpires
-> 000000f82dd4add8 System.Runtime.Caching.ExpiresBucket[]
-> 000000f82dd4bc28 System.Runtime.Caching.ExpiresBucket
在
000000faaceca438 Ninject.StandardKernel
上运行 !objsize 看起来需要很长时间,这意味着它引用了大量的对象,可能是所有 4000 万个 System.Runtime.Caching.ExpiresBucket
对象之一...是什么导致了内存泄漏?我应该如何识别出有问题的类或代码?在 gcroot 输出中没有任何对我们自己代码的引用,所以它是由我们正在使用的安装库中的错误引起的吗?还是因为 Ninject 的一个 bug?我们正在使用 v3.2.2(不是最新版本,我知道)。
Ninject.Web.Common
? - Steven