Server-side Fingerprinting

Server-side fingerprinting is also configured with a config similar to grouping enhancements, but the syntax is slightly different. The matchers are the same, but instead of flipping flags, a fingerprint is assigned and it overrides the default grouping entirely.

These rules can be configured on a per-project basis under Settings > Projects > [project] > General Settings > Grouping Settings. Group Settings has input fields where you can write custom fingerprinting rules. The syntax follows the syntax from Discover queries. If you want to negate the match, prefix the expression with an exclamation mark (!).

All values are matched against, and in the case of stack traces, all frames are considered. If all matches in a line match, then the fingerprint is applied.

# You can use comments to explain the rules.  Rules themselves follow the
# following syntax:
matcher:expression -> list of values
# The list of values can be hardcoded or substituted values.

Below is a practical example, which groups exceptions of a specific type together:

error.type:DatabaseUnavailable -> system-down
error.type:ConnectionError -> system-down

error.value:"connection error: *" -> connection-error, {{ transaction }}


Matchers generally use globbing syntax. The following matchers are available:


alias: type

Matches on an exception type (exception name). The match is performed as a case sensitive glob.

error.type:ZeroDivisionError -> zero-division
error.type:ConnectionError -> connection-error


alias: value

Matches on the exception value. Errors or exceptions often have human-readable descriptions (values) associated with them. This matcher allows a case insensitive match.

error.value:"connection error (code: *)" -> connection-error
error.value:"could not connect (*)" -> connection-error


Matches on a log message. It will also automatically check for the additional exception value as they can be hard to keep apart. The matching is case insensitive.

message:"system encountered a fatal problem: *" -> fatal-log


Matches on the name of the logger, which is useful to combine all messages of a logger together. This match is case sensitive.

logger:"com.myapp.mypackage.*" -> mypackage-logger


Matches on the log level. The match is case insensitive.

logger:"com.myapp.FooLogger" level:"error" -> mylogger-error


Matches on the value of the tag tag_name. This can be useful to filter down certain types of events. For instance, you can separate events caused by a specific server:

tags.server_name:"canary-*.mycompany.internal" -> canary-events


alias: path

Matches on the path of an event and is case insensitive. It uses path globbing semantics, which means that * does not match a slash, but ** does. Note that this matcher matches on both abs_path and filename as SDKs can be quite inconsistent about how these values are supported. If the glob matches on either of these values, it's considered a match.

stack.abs_path:"**/my-utils/*.js" -> my-utils, {{ error.type }}


alias: module

Similar to stack.abs_path but matches on the module name instead. The match is case sensitive and regular globbing rules apply (* also matches slashes).

stack.module:"*/my-utils/*" -> my-utils, {{ error.type }}


alias: function

Checks if any of the functions in the stack trace match the glob. The match is case sensitive:

stack.function:"my_assertion_failed" -> my-assertion-failed


alias: package

Matches on the "package" of a frame. This is typically the name of the debug symbol/object file that contains a frame. If any of the frames match this object file, then it matches.

stack.package:"**/libcurl.dylib" -> libcurl
stack.package:"**/" -> libcurl


Used to "scope" down the matcher. The following families exist: javascript for any type of JavaScript event, native for any type of Native event. Any other platform is called other.

family:native !stack.module:"myproject::*" -> not-from-my-project


Checks if the frame is in-app or not. It is particularly useful when combined with another matcher. Possible values are yes and no:

app:yes stack.function:"assert" -> assert

Combining Matchers

When multiple matchers are combined, they all need to match. Matchers that operate on frames must all apply to the same frame; otherwise, they are not considered a match.

For instance, if you match on both the function name and module name, then a match only exists if a frame matches both the function name and the module name. It's not enough for a frame to match only with the function name, even if another frame would match the module name by itself.

# this matches if a frame exists with a specific function and module name
# and also a specific error type is thrown
error.type:ConnectionError stack.function:"connect" stack.module:"bot" -> bot-error


On the right-hand side of the fingerprint, you can use constant values and variables. Variables are substituted automatically and have the same name as matchers, but they might be filled in differently.

Variables are enclosed in double braces ({{ variable_name }}).

{{ default }}

This fills in the default fingerprint that would be produced by the normal grouping operation. It is useful if you want to subdivide an already existing group by something else:

stack.function:"query_database" -> {{ default }}, {{ transaction }}

{{ transaction }}

This fills in the name of the transaction into the fingerprint. It will force the creation of a group per transaction:

error.type:"ApiError" -> api-error, {{ transaction }}

{{ error.type }}

alias: {{ type }}

This fills in the name of the error that occurred. When chained exceptions are used, it will be the most recently thrown error. This will force the creation of a group per transaction:

stack.function:"evaluate_script" -> script-evaluation, {{ error.type }}

{{ stack.function }}

alias: {{ function }}

This fills in the function name of the "crashing frame," also known as the application code's topmost frame.

error.type:"ScriptError" -> script-evaluation, {{ stack.function }}

{{ stack.module }}

alias: {{ module }}

This fills in the module name of the "crashing frame," also known as the application code's topmost frame.

error.type:"ScriptError" -> script-evaluation, {{ stack.module }}

{{ stack.package }}

alias: {{ package }}

This fills in the package name (object file) of the "crashing frame," also known as the application code's topmost frame.

stack.function:"assert" -> assertion, {{ stack.package }}

{{ logger }}

This fills in the name of the logger that caused an event.

message:"critical connection error*" -> connection-error, {{ logger }}

{{ level }}

This fills in the name of the log level that was used to create an event.

message:"connection error*" -> connection-error, {{ logger }}, {{ level }}

{{ tags.tag_name }}

This fills in the value of a tag into the fingerprint, which can, for instance, be used to split events by server name or something similar.

message:"connection error*" -> connection-error, {{ tags.server_name }}
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