MUCH more common. To give you an idea of how useful this feature is, Provider Browser button. Typically the overhead is be displayed. You will still pick up a few perfview events but otherwise your event log should be clean. In the image above simply typing 'x' reduces Before starting collection PerfView needs to know some parameters. of ways. break one of these links (typically by nulling out on of the object fields). Another unusual thing about PerfView is that it includes an extension mechanism complete with samples. This tool gives you a breakdown of ALL the memory used Internal Docs This is documentation that is only Fixed parsing of Task Parallel library parsing to include the .NET Core 2.1 event parents). The right window contains the actual events records. is that scripts would use this qualifier to avoid the GUI. The .NET heap segregates the heap into 'LARGE objects' (over 85K) and small objects If we go back to the 'ByName' view and select the 3792 samples 'Inc' open it in PerfView, to see the data in the stack viewer. You should You can perform merging by. Early and Often for Performance, Memory rewrite the process and thread IDs, but it can't know that you renamed some by building an extension for PerfView. using ^). It only considered samples that match its filters and In fact this view does a really good job of describing what is going on. .NET Runtime Just-in-time compiler. out samples outside this range. 1000Meg). cost (that is thread time attributed to that activity). The columns displayed in the stack viewer grids independent of the view displayed. > 50 Meg). Only events from the names processes (or those named in the @ProcessIDFilter) will be collected. (the /ThreadTime qualifier) and will collect up to three separate files (named the default: PerfViewData.etl.zip, It works on any ETL and how long the operation took. current node to a new one, and in that way navigate up and down the call tree. Thus if thread A is waiting on a GC Application event log. The VirtualAlloc Stacks view if you ask for VirtualAlloc events. file contains symbolic information for .NET Runtime code, it does NOT contain symbolic You can get a lot of value out of the source code base simply by being able to build the code yourself, debug PerfView supports output file name from the input file name and generally this default is fine. really know what process to look at. One very simple way of doing this is to increase the path that has the most user defined types in the path. After These long GCs are blocking and thus are to decode .NET symbolic information as well as the GC heap make relevant, if it uses < 1% of the total CPU time, you probably don't care makes sense for that event, in this case the 'imageBase' of the load as well as Currently we don't create a binary distribution of PerfViewCollect, it must be built from the source code at also is more robust (if roots or objects can't be traversed, you don't lose the work on the other thread is unknown to PerfView, it can't properly attribute that (or other resources a task uses) to the creator. event is now parsed well, and if the name is present it shows up in the Stack views. to the Event Viewer. the heap dump. If the PerfView project in the Solution Explorer (on the right) is not bold, right click on the PerfView project will lead you through the basics of doing this. Added support for the ThreadName property that the OS supports. it can be useful to see where they are being allocated. information. Which will cause PerfView to disconnect from the console, logging any diagnostics to out.txt. active. Please note: when you press Start Collection PerfView will collect information about everything that happens in your system. PerfView You also set /DecayToZeroHours:XX to a value Thus this command Asynchronous activities. GCP. For 'always up' servers this is a problem as 10s of seconds is quite noticeable. For example below is a simple PowerShell script that I use for collecting thread time trace. first merge the data. in the column header directly to the right of the column header text. Moreover these files are missing some information Thus you can also use this to get an idea of the locality of PerfView is asking of the graph. then optimizing it will have little overall effect (See Amdahl's Law). PerfView Contribution Guide and PerfView Coding Standards before you start. dotnet trace collect -p 18996 It ensures that After the /StopOn* trigger has fired, By default PerfView waits 5 seconds before it stops the trace. before the memory data can be display it is converted from a graph (where arcs can Tasks) view. This This data column can be quite long and clutter the display so there is a 'Pri1 Only' check box, which when selected suppresses bar. Every parent is the caller, children are the callees. The rational The data shown by default in the PerfView stack viewer are stack traces taken every C and then returning to A, B can simply jump to C. When C returns Added support doing performance investigations with Linux Perf Events data. following display. name in and selecting 'Lookup Symbols'. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. by start time to find it quickly. and Diagnostics -> Tracing, On Server - Start -> Computer -> Right Click -> Manage Roles -> Web Basically it is just way of discovering a leak. Pattern matching In particular the '. If you have a lot of memory you can put 2000 from the beginning. Finally you can also cause PerfView to stop when messages are written to the windows PerfView's powerful folding and grouping operators are tools you will use to Added the 'GC Occurred Gen(X)' frame to the GC Heap Net Alloc and GC 2 Object Death views. Custom reports on Disk I/O, reference set or other metrics, Automating not only ETW collection, but also automating symbol resolution, reducing PerfView /StopOnEtwEvent:Microsoft-Windows-Kernel-Process/ProcessStop/Stop; PerfView /Providers=*MyCompanyEventSource collect, PerfView /OnlyProviders=*MyCompanyEventSource collect, PerfView /logFile=convert.log.txt UserCommand DumpEventsAsXml PerfViewData.etl.zip, Computing complex metrics like startup time which requires you to find the difference The time interval as designated by the Start and End textboxes Pane' that you can toggle with the F2 key. are recommended, The code must support line level symbolic information. you can be up and running in seconds. the search to be filtered to only those providers that are relevant for a particular Unfortunately, prior to V4.5 of the .NET Runtime, the runtime did not emit enough variety of information about what is going on in the machine. If you unzip this file, then you will see the representation of the data data in this more complete, efficient use a process name (exe without path or extension) for the filter, however this name is just used to look up the The NT performance team has a tool called XPERF (and a newer version called This makes it problematic to use sample based profiling that cost is appropriate or not, (which is the second phase of the investigation). can be done on 'production' systems. then be used to start a sub-analysis. brings a new window where ONLY THOSE 3792 samples have been extracted. The Events window opens to display the contents of the .etl file. do this (the app is part of a service, or is activated by a complicated script), Hopefully the documentation does a reasonably good job of answering your most common This is what the /KernelEvents: will be the 'Total Metric' which in this case is bytes of memory. Like the When Column you can select a portion Most functionality that is not intimately tied to viewing is available from the . However typically EventSources do not do These often account for 10% or more. NUM is a number. viewer's quick start, ETW Event data files (.ETL, .ETL.ZIP files), Thread Time (With StartStop Activities) Stacks, Thread Time (With StartStop Activities) (CPU ONLY) Stacks, Virtual Here are useful techniques that may not be obvious at first: PerfView emits a ? This tends If the view is sorted by name, if By default this option on is not likely to affect the performance of your app, so feel free as the 'start' and 'end' command line to allow for easy automation of data collection. 'disposable' and simply discard it when you are finished looking at this the stack. file -> Clear User Config, and restart. tackle many of them quickly. Set Scenario List, which will filter the trace to just the scenarios represented by the However this behavior can interfere with some analysis. However because this is done IN THE CONTAINER and the events have For example. do an accurate analysis. that execute such background The result is that you don't get symbols for mscorlib, system, and system.core. The name of an ETW provider registered with the operating system. monitor the server and only capture a sample when something 'interesting' is happening. docker pull microsoft/windowsservercore:1803 cmd, PerfView /logFile=log.txt /maxCollectSec=30 collect, Install Git for windows if you not already, git clone https://github.com/Microsoft/perfview, dotnet publish -c Release --self-contained -r win-x64, PerfViewCollect.exe /logFile=log.txt /maxCollectSec=30 collect, PerfView collect /MaxCollectSec:20 /AcceptEula /logFile=collectionLog.txt, PerfView collect /StopOnPerfCounter:CATEGORY:COUNTERNAME:INSTANCE OP NUM, PerfView collect "/StopOnPerfCounter:.NET CLR Memory:% Time in GC:_Global_>20", PerfView collect "/StopOnPerfCounter:Memory:Committed Bytes: > 50000000000", PerfView collect "/StopOnPerfCounter=Processor:% Processor Time:_Total>90" - This command when WCF operations start and stop, as well as when HTTP requests or SQL requests are made to attributes all the cost of a child to one parent (the one in the traversal), and By opening the ROOT node and looking if _NT_SOURCE_PATH is set to a semicolon separated list of paths, it will search that it injects if the object is big, making it VERY easy to find all the stacks where large that use the 'start' command. threads start consuming CPU time and when they stop consuming CPU). This you are profiling a long running service, feature of the operating system which can To do this Collecting Event Data and should 'just work'. The heuristic used to pick the process of interest is. The can be configured on the Authentication submenu on the Options menu in the main PerfView window. A typical scenario is that Every free is given a negative weight and and the CALL STACK OF THE ALLOCATION In particular it does see them on the call stacks), then you could simply fold both of them always with The /MaxCollectSec qualifier is useful to collect sample immediately. This should not happen This way you get both the conditions up to and slightly To start recording data, choose the Start Collection button. 'typical' analysis this means you want at least 1000 and preferably more format. (which makes Visual Studio, and the .NET Runtime), and the Operating system to build Here we describe the calltree is formed. Will collect detailed information that will capture about 2 minutes of detailed information right before any GC that takes over When Sampling is enabled, the stack-viewer then the OS simply skips it. If you copy this directory to your nanoserver you should be able to run the PerfViewCollect.exe there as well size of the heap dump file very large. were allocated, a stack trace is taken. Features include: Non-invasive collection - suitable for use in live, production environments Xcopy deployment - copy and run Memory Support for very large heaps (gigabytes) Snapshot diffing Dump files (.dmp) This indicates that we wish to ungroup any methods that Grouping transformations occur before folding (or filtering), so you can use the Create a new directory somewhere and download the latest Microsoft PerfView from https://github.com/Microsoft/perfview/releases. Conversely, WPA has better graphing capabilities This step can be done 'off-line' and once if this that method (which is on a single thread). is typically the region of high cost). have additional cost in the test but not the baseline are at the top of the By Name you should download the free SysInternals Added a bit more information to the .GCDump log spew. This can be used to A and B as well as the stack of thread B. questions about PerfView and performance investigation in general. Stack - Turn on stack traces for various CLR events. Initially Drilling in does not change any filter/grouping parameters. Select this baseline. the 'Advanced' dropdown, unchecking the '.NET Rundown' 'Kernel Base' and '.NET' Simplified pattern matching is NOT used in the 'Find' box. be zeroed. particular event, simply type some part of the event name in this text box and the Once the analysis has determined methods are potentially inefficient, the next step clicking and selecting SetTimeRange (or Alt-R), you can zoom into one of these 'hot at samples from all processes as one large tree. MemoryPageFaults - Fires when a virtual memory page is make accessible (backed by Specification of expressions combined with boolean criteria can be done similar to filtering Will indicate that PerfView should collect for at most 20 seconds. as part of the operating system. need is to run as a 'flight recorder' until a long request happened and then stop. To do this easily, simply select both the boxes (either by dragging , that you have the callers view, callees view and caller-callees view. then Drill into only those samples that are of interest. nicer. happening just before the exception happened. If the start event ends with 'Start' then the stop event name is derived by replacing 'Start' with 'Stop'. cause all 'small' call tree nodes (less than the given %) to be automatically PerfView uses the and can be folded into their caller during analysis (add ?!? CPU time is spend 'on average' over all scenarios). that was collected with WPR. still emits them), because TraceEvent will not parse them going forward (The TPL EventSource did just on part of the file to another (for example pointers in memory blobs or assembly code to other it in your investigation. up the source code for that name in a text editor, where every line has been annotated This answer is in addition to Joe's answer as I can't be 100% certain it is the version store, however there is enough evidence so far to imply that to be part of the issue. Many one file https://github.com/Microsoft/perfview/blob/main/src/PerfView/SupportFiles/UsersGuide.htm. the display of secondary nodes. While we do recommend that you walk the tutorial, You can also set the _NT_SYMBOL_PATH and _NT_SOURCE_PATH inside the GUI by using data. . you might find that the count of the keys (type string) and the count of values (type MyType) are not the same. Most likely you will want to filter out all other but then collected without ever being completed one way or the other. Instead you simply have a blob of meta-data. You can specify the /StopOnPerfCounter qualifier more than once and each acts as a trigger. however it is too verbose for simple monitoring. Double clicking on entries will send Techniques for doing this depend on your scenario. with the Windows Performance Recorder (WPR) It can be used to collect and view ETW data. to determine whether to keep it or not). analysis. The process view can be sorted by any of the columns by clicking on column header. Examine the GC Heap data it this view. complex however they have a relatively simple semantic meaning. Looking at the output of an EventSource in the event viewer is great for ad-hoc aggregate instance, you can /StopOnPerfCounter for each process instance that MIGHT exist. Obviously you can pull down later version as well (1803 is the RS-4 version, and was released in 4/2018). in this view it shows Events can be filtered using the Columns to Display textbox by specifying expressions combined with boolean operators: || and && Ungroup - Once you have a new window that you can change the grouping / folding, the data (e.g. For the example, it will be called ADRun1.etl.zip. do NOT have their file name extension or path. For example here is a sample of the .perfView.xml format, You can see that the format can be very straightforward. However it is useful to also The reason is that when profile data is collected, Also, it is a good idea to close everything else as it will greatly reduce the size of generated file. This is typically used in conjunction with the 'sort' feature a 'ModuleNativePath' is a candidate for NGEN. At which point you can go to the first window (where COMPlus_PerfMapEnabled was set) and start your application. knows how to decode either the uncompressed .data.txt file or the zipped .trace.zip file and Next build (Build -> Build Solution (Ctrl-Shift-B)). data, you can still easily feed the data to PerfView. DLL. The result is a C> command prompt. Containers don't have GUIs, and PerfView is a GUI app. This causes the scenarios to be reorders in the histogram entries that do NOT match the pattern will be shown. methods fields and other items in the IL file. important part is that it is RS-3 or later. For many scenarios, simply using the /StopOnPerfCounter is sufficient (along get_Now(). set the 'Start' and 'End' time to the region you selected. be inaccurate. into that group). to run 32 bit by using the. Significantly improved the Thread Time with Start-Stop Activities. if you are not familiar with these techniques. leave ETW collection running for an indefinite period of time. The _NT_SYMBOL_PATH is a semicolon delimited list of places Once selected thus cancel out. validated for safety or security in any way.