Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

[Instrumentation.Runtime] Add description for metrics in README.md #475

Merged
merged 24 commits into from
Jul 7, 2022
Merged

[Instrumentation.Runtime] Add description for metrics in README.md #475

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
24 commits
Select commit Hold shift + click to select a range
a1fcea6
Added metrics in `README.md`
xiang17 Jun 29, 2022
8a19c6a
Update metric names
xiang17 Jun 29, 2022
2f1bac1
Adjust title hierarchy and format
xiang17 Jun 29, 2022
23be2dd
Take description from code
xiang17 Jun 29, 2022
8918e4a
Evenly distribute tables
xiang17 Jun 29, 2022
832c2a2
Add two notes
xiang17 Jun 29, 2022
89763b7
Change unordered list to use star
xiang17 Jun 29, 2022
438a9a4
Update `By` to `bytes`
xiang17 Jun 29, 2022
bacdd47
Evenly distribute tables
xiang17 Jun 29, 2022
38eec1e
Making the note more clear for garbage collection counts, especially …
xiang17 Jun 29, 2022
ec96363
Reword
xiang17 Jun 29, 2022
221e001
Adding a note for `exception.count`
xiang17 Jun 29, 2022
57fb12d
Merge branch 'main' into xiang17/updatedoc
xiang17 Jun 29, 2022
29d453e
Update unit for exception.count
xiang17 Jun 30, 2022
67c3857
Apply suggestions from code review
xiang17 Jul 1, 2022
16b728b
Reverting the change for "contention"
xiang17 Jul 1, 2022
cf8f67f
Evenly distribute table
xiang17 Jul 1, 2022
efe8206
Update code according to feedback on doc
xiang17 Jul 1, 2022
7c056dc
Merge branch 'main' into xiang17/updatedoc
xiang17 Jul 1, 2022
f15617a
Remove version/view parameter
xiang17 Jul 6, 2022
ec93083
Update unit to `{contended_acquisitions}`
xiang17 Jul 6, 2022
6209a63
Merge branch 'main' into xiang17/updatedoc
cijothomas Jul 6, 2022
b678023
Update `exceptions.count`
xiang17 Jul 7, 2022
aa17f91
Merge branch 'main' into xiang17/updatedoc
xiang17 Jul 7, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
132 changes: 132 additions & 0 deletions src/OpenTelemetry.Instrumentation.Runtime/README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -60,6 +60,138 @@ using var meterProvider = Sdk.CreateMeterProviderBuilder()
Refer to [Program.cs](../../examples/runtime-instrumentation/Program.cs) for a
complete demo.

## Metrics

### GC related metrics
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'd suggest to use heading for each of the metric, instead of the table. It'll be easier to link to individual metric that way. And we can write very long, details about the metric. (Description in this doc is not that important, as it is already part of metric descripption.) We could do more here, like "what value is considered typically okay, what is the action item if this value is high/low etc."

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

eventually "tutorials:" like this : https://docs.microsoft.com/en-us/dotnet/core/diagnostics/debug-threadpool-starvation

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I was more of thinking to make it easier for people who want to have a quick glance to know what to expect without having to dive into the code. I like your tutorial idea, and we can also include tools to use, etc. but it would be much more than the scope of this PR.


| Name | Description | Units | Instrument Type | Value Type | Attribute Key(s) | Attribute Values |
|-------------------------------------------------|-----------------------------------------------------------------------|-----------------|-------------------|------------|------------------|------------------|
| process.runtime.dotnet.**gc.collections.count** | Number of garbage collections that have occurred since process start. | `{collections}` | ObservableCounter | `Int64` | generation | gen0, gen1, gen2 |

Note: Collecting a generation means collecting objects in that generation and all
its younger generations. However, each dimension for this metrics doesn't include
the collection counts for the lower generation.
e.g. count for gen1 is `GC.CollectionCount(1) - GC.CollectionCount(0)`.

The API used to retrieve the value is:

* [GC.CollectionCount](https://docs.microsoft.com/dotnet/api/system.gc.collectioncount):
The number of times garbage collection has occurred for the specified generation
of objects.

#### Additional GC metrics only available when targeting .NET Core 3.1 or later

| Name | Description | Units | Instrument Type | Value Type | Attribute Key(s) | Attribute Values |
|------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|-------------------|------------|------------------|------------------|
| process.runtime.dotnet.**gc.allocations.size** | Count of bytes allocated on the managed GC heap since the process start. .NET objects are allocated from this heap. Object allocations from unmanaged languages such as C/C++ do not use this heap. | `bytes` | ObservableCounter | `Int64` | | |

The API used to retrieve the value is:

* [GC.GetTotalAllocatedBytes](https://docs.microsoft.com/dotnet/api/system.gc.gettotalallocatedbytes):
Gets a count of the bytes allocated over the lifetime of the process. The returned
value does not include any native allocations. The value is an approximate count.

#### Additional GC metrics only available when targeting .NET6 or later

| Name | Description | Units | Instrument Type | Value Type | Attribute Key(s) | Attribute Values |
|-------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|-----------------|------------|------------------|----------------------------|
| process.runtime.dotnet.**gc.committed_memory.size** | The amount of committed virtual memory for the managed GC heap, as observed during the latest garbage collection. Committed virtual memory may be larger than the heap size because it includes both memory for storing existing objects (the heap size) and some extra memory that is ready to handle newly allocated objects in the future. The value will be unavailable until garbage collection has occurred. | `bytes` | ObservableGauge | `Int64` | | |
| process.runtime.dotnet.**gc.heap.size** | The heap size (including fragmentation), as observed during the latest garbage collection. The value will be unavailable until garbage collection has occurred. | `bytes` | ObservableGauge | `Int64` | generation | gen0, gen1, gen2, loh, poh |
| process.runtime.dotnet.**gc.heap.fragmentation.size** | The heap fragmentation, as observed during the latest garbage collection. The value will be unavailable until garbage collection has occurred. | `bytes` | ObservableGauge | `Int64` | generation | gen0, gen1, gen2, loh, poh |

Note: `ObservableGauge` should be changed to `ObservableUpDownCounter` once available,
as `ObservableUpDownCounter` is the best fit of instrument type. The same applies
to all the `ObservableGauge` below.

The APIs used to retrieve the values are:

* [GCMemoryInfo.TotalCommittedBytes](https://docs.microsoft.com/dotnet/api/system.gcmemoryinfo.totalcommittedbytes):
Gets the total committed bytes of the managed heap.

* [GC.GetGCMemoryInfo().GenerationInfo[i].SizeAfterBytes](https://docs.microsoft.com/dotnet/api/system.gcgenerationinfo):
Represents the size in bytes of a generation on exit of the GC reported in GCMemoryInfo.

* [GCGenerationInfo.FragmentationAfterBytes Property](https://docs.microsoft.com/dotnet/api/system.gcgenerationinfo.fragmentationafterbytes)
Gets the fragmentation in bytes on exit from the reported collection.

### JIT Compiler related metrics

These metrics are only available when targeting .NET6 or later.

| Name | Description | Units | Instrument Type | Value Type | Attribute Key(s) | Attribute Values |
|-------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|-------------------|------------|------------------|------------------|
| process.runtime.dotnet.**jit.il_compiled.size** | Count of bytes of intermediate language that have been compiled since the process start. | `bytes` | ObservableCounter | `Int64` | | |
| process.runtime.dotnet.**jit.methods_compiled.count** | The number of times the JIT compiler compiled a method since the process start. The JIT compiler may be invoked multiple times for the same method to compile with different generic parameters, or because tiered compilation requested different optimization settings. | `{methods}` | ObservableCounter | `Int64` | | |
| process.runtime.dotnet.**jit.compilation_time** | The amount of time the JIT compiler has spent compiling methods since the process start. | `ns` | ObservableCounter | `Int64` | | |

The APIs used to retrieve the values are:

* [JitInfo.GetCompiledILBytes](https://docs.microsoft.com/dotnet/api/system.runtime.jitinfo.getcompiledilbytes):
Gets the number of bytes of intermediate language that have been compiled.
The scope of this value is global. The same applies for other JIT related metrics.

* [JitInfo.GetCompiledMethodCount](https://docs.microsoft.com/dotnet/api/system.runtime.jitinfo.getcompiledmethodcount):
Gets the number of methods that have been compiled.

* [JitInfo.GetCompilationTime](https://docs.microsoft.com/dotnet/api/system.runtime.jitinfo.getcompilationtime):
Gets the amount of time the JIT Compiler has spent compiling methods.

### Threading related metrics

These metrics are only available when targeting .NET Core 3.1 or later.

| Name | Description | Units | Instrument Type | Value Type | Attribute Key(s) | Attribute Values |
|--------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------|-------------------|------------|------------------|------------------|
| process.runtime.dotnet.**monitor.lock_contention.count** | The number of times there was contention when trying to acquire a monitor lock since the process start. Monitor locks are commonly acquired by using the lock keyword in C#, or by calling Monitor.Enter() and Monitor.TryEnter(). | `{contended_acquisitions}` | ObservableCounter | `Int64` | | |
| process.runtime.dotnet.**thread_pool.threads.count** | The number of thread pool threads that currently exist. | `{threads}` | ObservableGauge | `Int32` | | |
| process.runtime.dotnet.**thread_pool.completed_items.count** | The number of work items that have been processed by the thread pool since the process start. | `{items}` | ObservableCounter | `Int64` | | |
| process.runtime.dotnet.**thread_pool.queue.length** | The number of work items that are currently queued to be processed by the thread pool. | `{items}` | ObservableGauge | `Int64` | | |
| process.runtime.dotnet.**timer.count** | The number of timer instances that are currently active. Timers can be created by many sources such as System.Threading.Timer, Task.Delay, or the timeout in a CancellationSource. An active timer is registered to tick at some point in the future and has not yet been canceled. | `{timers}` | ObservableGauge | `Int64` | | |

The APIs used to retrieve the values are:

* [Monitor.LockContentionCount](https://docs.microsoft.com/dotnet/api/system.threading.monitor.lockcontentioncount):
Gets the number of times there was contention when trying to take the monitor's
lock.
* [ThreadPool.ThreadCount](https://docs.microsoft.com/dotnet/api/system.threading.threadpool.threadcount):
Gets the number of thread pool threads that currently exist.
* [ThreadPool.CompletedWorkItemCount](https://docs.microsoft.com/dotnet/api/system.threading.threadpool.completedworkitemcount):
Gets the number of work items that have been processed so far.
* [ThreadPool.PendingWorkItemCount](https://docs.microsoft.com/dotnet/api/system.threading.threadpool.pendingworkitemcount):
Gets the number of work items that are currently queued to be processed.
* [Timer.ActiveCount](https://docs.microsoft.com/dotnet/api/system.threading.timer.activecount):
Gets the number of timers that are currently active. An active timer is registered
to tick at some point in the future, and has not yet been canceled.

### Assemblies related metrics

| Name | Description | Units | Instrument Type | Value Type | Attribute Key(s) | Attribute Values |
|---------------------------------------------|----------------------------------------------------------|----------------|-----------------|------------|------------------|------------------|
| process.runtime.dotnet.**assemblies.count** | The number of .NET assemblies that are currently loaded. | `{assemblies}` | ObservableGauge | `Int64` | | |

The API used to retrieve the value is:

* [AppDomain.GetAssemblies](https://docs.microsoft.com/dotnet/api/system.appdomain.getassemblies):
Gets the number of the assemblies that have been loaded into the execution context
of this application domain.

### Exception counter metric

| Name | Description | Units | Instrument Type | Value Type | Attribute Key(s) | Attribute Values |
|---------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|-----------------|------------|------------------|------------------|
| process.runtime.dotnet.**exceptions.count** | Count of exceptions that have been thrown in managed code, since the observation started. The value will be unavailable until an exception has been thrown after OpenTelemetry.Instrumentation.Runtime initialization. | `{exceptions}` | Counter | `Int64` | | |

Note: The value is tracked by incrementing a counter whenever an AppDomain.FirstChanceException
event occurs. The observation starts when the Runtime instrumentation library is
initialized, so the value will be unavailable until an exception has been
thrown after the initialization.

Relevant API:

* [AppDomain.FirstChanceException](https://docs.microsoft.com/dotnet/api/system.appdomain.firstchanceexception)
Occurs when an exception is thrown in managed code, before the runtime searches
the call stack for an exception handler in the application domain.

## Troubleshooting

This component uses an
Expand Down
Loading