Adding Sentry to your app gives you a great deal of very valuable information about errors and performance you wouldn't otherwise get. And lots of information is good -- as long as it's the right information, at a reasonable volume.
The Sentry SDKs have several configuration options to help you filter out events.
We also offer Inbound Filters to filter events in sentry.io. We recommend filtering at the client level though, because it removes the overhead of sending events you don't actually want. Learn more about the fields available in an event.
Configure your SDK to filter error events by using the
before_send callback method and configuring, enabling, or disabling integrations.
All Sentry SDKs support the
before_send callback method.
before_send is called immediately before the event is sent to the server, so it’s the final place where you can edit its data. It receives the event object as a parameter, so you can use that to modify the event’s data or drop it completely (by returning
null) based on custom logic and the data available on the event.
In Python a function can be used to modify the event or return a completely new one. If you return
None, the event will be discarded.
import sentry_sdk def strip_sensitive_data(event, hint): # modify event here return event sentry_sdk.init( # ... before_send=strip_sensitive_data, )
Note also that breadcrumbs can be filtered, as discussed in our Breadcrumbs documentation.
before_send callback is passed both the
event and a second argument,
hint, that holds one or more hints.
hint holds the original exception so that additional data can be extracted or grouping is affected. In this example, the fingerprint is forced to a common value if an exception of a certain type has been caught:
import sentry_sdk def before_send(event, hint): if 'exc_info' in hint: exc_type, exc_value, tb = hint['exc_info'] if isinstance(exc_value, DatabaseUnavailable): event['fingerprint'] = ['database-unavailable'] return event sentry_sdk.init( # ... before_send=before_send, )
For information about which hints are available see hints in Python.
When the SDK creates an event or breadcrumb for transmission, that transmission is typically created from some sort of source object. For instance, an error event is typically created from a log record or exception instance. For better customization, SDKs send these objects to certain callbacks (
before_breadcrumb or the event processor system in the SDK).
Hints are available in two places:
Event and breadcrumb
hints are objects containing various information used to put together an event or a breadcrumb. Typically
hints hold the original exception so that additional data can be extracted or grouping can be affected.
For events, hints contain properties such as
syntheticException (used internally to generate cleaner stack trace), and any other arbitrary
data that you attach.
For breadcrumbs, the use of
hints is implementation dependent. For XHR requests, the hint contains the xhr object itself; for user interactions the hint contains the DOM element and event name and so forth.
In this example, the fingerprint is forced to a common value if an exception of a certain type has been caught:
import sentry_sdk def before_send(event, hint): exc_info = hint.get("exc_info") if exc_info and isinstance(exc_info, DatabaseUnavailable): event["fingerprint"] = ["database-unavailable"] return event sentry_sdk.init( # ... before_send=before_send, )
- The original exception that caused the Sentry SDK to create the event. This is useful for changing how the Sentry SDK groups events or to extract additional information.
- When a string or a non-error object is raised, Sentry creates a synthetic exception so you can get a basic stack trace. This exception is stored here for further data extraction.
- For breadcrumbs created from browser events, the Sentry SDK often supplies the event to the breadcrumb as a hint. This, for instance, can be used to extract data from the target DOM element into a breadcrumb.
- For breadcrumbs created from console log interceptions. This holds the original console log level and the original input data to the log function.
- For breadcrumbs created from HTTP requests. This holds the response object (from the fetch API) and the input parameters to the fetch function.
- For breadcrumbs created from HTTP requests. This holds the request and response object (from the node HTTP API) as well as the node event (
- For breadcrumbs created from HTTP requests done via the legacy
XMLHttpRequestAPI. This holds the original xhr object.
By default the Python SDK captures all error logs as events. If you see a particular kind of error very often that has a
logger tag, you can ignore that particular logger entirely. For more information see our logging integration.
To prevent certain transactions from being reported to Sentry, use the
traces_sampler configuration option, which allows you to provide a function to evaluate the current transaction and drop it if it's not one you want. (It also allows you to sample different transactions at different rates.)
traces_sample_rate config options are mutually exclusive. If you define a
traces_sampler to filter out certain transactions, you must also handle the case of non-filtered transactions by returning the rate at which you'd like them sampled.
In its simplest form, used just for filtering the transaction, it looks like this:
def traces_sampler(sampling_context): if "...": # Drop this transaction, by setting its sample rate to 0% return 0 else: # Default sample rate for all others (replaces traces_sample_rate) return 0.1 sentry_sdk.init( # ... traces_sampler=traces_sampler, )
Learn more about configuring the sample rate.