Custom Grouping Enhancements

If you use stack traces for grouping, the enhancements rules influence the data that feed into that algorithm. These rules can be configured on a per-project basis under Settings > Projects > [project] > General Settings > Grouping Settings.

Enhancements are straightforward rules. Each line is a single enhancement rule; one or multiple match expressions are followed by one or multiple actions to be executed when all expressions match. All rules are executed from top to bottom on all frames in the stack trace.

The syntax for grouping enhancements is similar to:

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matcher-name:expression other-matcher:expression ... action1 action2 ...

The syntax follows the syntax from Discover queries. If you want to negate the match, you can prefix the expression with an exclamation mark (!).

The following is a practical example of how this looks:

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# mark all functions in the std namespace to be outside the app
family:native stack.function:std::*       -app

# mark all code in node modules not to be in app
stack.abs_path:**/node_modules/**         -app

# remove all generated javascript code from all grouping
stack.abs_path:**/generated/**.js         -group

Matchers

Multiple matchers can be defined in a line. The following matchers are available:

family

Matches on the general platform family, which currently includes javascript, native and other. Comma separate rules to apply them to multiple platforms.

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family:javascript,native stack.abs_path:**/generated/**  -group

stack.abs_path

alias: path

This matcher is case insensitive with Unix glob behavior on a path in a stack trace. The path separators are normalized to /. As a special rule, if the filename is relative, it still matches on **/.

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# match on all files under `project` with a `.c` extension
stack.abs_path:**/project/**.c` +app

# matches on vendor/foo without sub folders
stack.abs_path:**/vendor/foo/*.c` -app

# matches on `foo.c` as well as `foo/bar.c`.
stack.abs_path:**/*.gen.c` -group

stack.module

alias: module

Module is similar to path but matches on the module. This is not used for Native but it is used for JavaScript, Python, and similar platforms. Matches are case sensitive, and normal globbing is available. Note that modules are not packages, which can be confusing for Native environments.

stack.function

alias: function

Matches on a function in a stack trace, and is case sensitive with normal globbing.

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stack.function:myproject_* +app
stack.function:malloc      -group

stack.package

alias: package

Matches on a package in a stack trace. The package is the container that contains a function or module. This is a .jar, a .dylib or similar. The same matching rules as for path apply. For example, this is typically an absolute path.

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stack.package:**/libcurl.dylib -group

app

Matches on the current state of the in-app flag of a stack trace frame. yes means the frame is in-app, no means it's not.

Actions

There are two types of actions: flag and variables setting.

  • flag: Flags identify the action to be taken if all matchers match. A flag needs to be prefixed with + to set it or - to unset it. If this expression is prefixed with a ^, it applies to frames above the matching frame (toward the crash). If prefixed with v it applies to frames below the matching frame (away from the crash). For instance, -group ^-group removes the matching frame and all frames above it from the grouping.
    • app: marks or unmarks a frame in-app
    • group: adds or removes a frame from grouping
  • variables: Variables can be set (variable=value). Currently, there is just one:
    • max-frames: sets the total number of frames to be considered for grouping. The default is 0 which means "all frames." If set to 3, only the top three frames are considereds.

If a line is prefixed with a hash (#), it's a comment and ignored.

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stack.abs_path:**/node_modules/** -group
stack.abs_path:**/app/utils/requestError.jsx -group
stack.abs_path:**src/getsentry/src/getsentry/** +app

family:native max-frames=3

stack.function:fetchSavedSearches v-group
stack.abs_path:**/app/views/**.jsx stack.function:fetchData ^-group

family:native stack.function:SpawnThread v-app -app
family:native stack.function:_NSRaiseError ^-group -app
family:native stack.function:std::* -app
family:native stack.function:core::* -app

Recommendations

These recommendations will greatly improve your out-of-the-box grouping experience.

Mark in-app Frames

To proactively improve your experience, help Sentry determine which frames in your stack trace are "in-app" (part of your own application) and which are not. The SDK defines the default rules, but in many cases, this can be improved on the server as well. In particular, for languages where server-side processing is necessary (for example, Native C, C++, or JavaScript), it's better to override this on the server.

For instance, the following marks all frames that are below a specific C++ namespace are in-app:

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stack.function:myapplication::* +app

You can also achieve the same result by marking other frames "not in-app." However, if that's the case, you should ensure that first all frames are set to "in-app" to override the defaults:

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app:no                   +app
stack.function:std::*    -app
stack.function:boost::*  -app

You need to force all frames to be in-app first because there might already have been some defaults set by the client SDK or earlier processing.

Cut Stack Traces

In many cases, you want to remove the top or bottom of the stack trace. For instance, many code bases use a common function to generate an error. In this case, the error machinery will appear as part of the stack trace. For example, if you use Rust, you likely want to remove some frames that are related to panic handling:

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stack.function:std::panicking::begin_panic       ^-app -app ^-group
stack.function:core::panicking::begin_panic      ^-app -app ^-group

Here we tell the system that all frames from begin-panic to the crash location are not part of the application (including the panic frame itself). All frames above are, in all cases, irrelevant for grouping.

Likewise, you can also remove the base of a stack trace. This is particularly useful if you have different main loops that drive an application:

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stack.function:myapp::LinuxMainLoop         v-group -group
stack.function:myapp::MacMainLoop           v-group -group
stack.function:myapp::WinMainLoop           v-group -group

Stack Trace Frame Limits

This isn't useful for all projects, but it can work well for large applications with many crashes. The default strategy is to consider most of the stack trace relevant for grouping. This means that every different stack trace that leads to a crashing function will cause a different group to be created. If you do not want that, you can force the groups to be much larger by limiting how many frames should be considered.

For instance, if any of the frames in the stack trace refer to a common external library, you could tell the system only to consider the top N frames:

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# always only consider the top 1 frame for all native events
family:native max-frames=1

# if the bug is in proprietarymodule.so, only consider top 2 frames
family:native stack.package:**/proprietarymodule.so  max-frames=2

# these are functions we want to consider much more of the stack trace for
family:native stack.function:KnownBadFunction1  max-frames=5
family:native stack.function:KnownBadFunction2  max-frames=5
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