Alextest

docs/platforms/python/tracing/configure-sampling/index.mdx

@@ -0,0 +1,288 @@
+---
+title: Configure Sampling
+description: "Learn how to configure sampling in your app."
+sidebar_order: 30
+---
+
+Sentry's tracing functionality helps you monitor application performance by capturing distributed traces, attaching attributes, and adding span performance metrics across your application. However, capturing traces for every transaction can generate significant volumes of data. Sampling allows you to control the amount of spans that are sent to Sentry from your application.
+
+Effective sampling is key to getting the most value from Sentry's performance monitoring while minimizing overhead. The `traces_sampler` function gives you precise control over which transactions to record, allowing you to focus on the most important parts of your application.
+
+## Sampling Configuration Options
+
+The Python SDK provides two main options for controlling the sampling rate:
+
+1. Uniform Sample Rate (`traces_sample_rate`)
+
+This option sets a fixed percentage of transactions to be captured:
+
+<PlatformContent includePath="/performance/traces-sample-rate" />
+
+With `traces_sample_rate` set to `0.25`, approximately 25% of transactions will be recorded and sent to Sentry. This provides an even cross-section of transactions regardless of where in your app they occur.
+
+2. Sampling Function (`traces_sampler`)
+
+For more granular control, you can use the `traces_sampler` function. This approach allows you to:
+
+- Apply different sampling rates to different types of transactions
+- Filter out specific transactions entirely
+- Make sampling decisions based on transaction data
+- Control the inheritance of sampling decisions in distributed traces
+
+<PlatformContent includePath="/performance/traces-sampler-as-sampler" />
+
+### Trace Sampler Examples
+
+1. Prioritizing Critical User Flows
+
+```python
+def traces_sampler(sampling_context):
+    ctx = sampling_context.get("transaction_context", {})
+    name = ctx.get("name", "")
+
+    # Sample all checkout transactions
+    if name and ('/checkout' in name or 
+                ctx.get("op") == 'checkout'):
+        return 1.0
+
+    # Sample 50% of login transactions
+    if name and ('/login' in name or 
+                ctx.get("op") == 'login'):
+        return 0.5
+
+    # Sample 10% of everything else
+    return 0.1
+
+sentry_sdk.init(
+    dsn="your-dsn",
+    traces_sampler=traces_sampler,
+)
+```
+
+2. Handling Different Environments and Error Rates
+
+```python
+def traces_sampler(sampling_context):
+    ctx = sampling_context.get("transaction_context", {})
+    environment = os.environ.get("ENVIRONMENT", "development")
+
+    # Sample all transactions in development
+    if environment == "development":
+        return 1.0
+
+    # Sample more transactions if there are recent errors
+    if ctx.get("data", {}).get("hasRecentErrors"):
+        return 0.8
+
+    # Sample based on environment
+    if environment == "production":
+        return 0.05  # 5% in production
+    elif environment == "staging":
+        return 0.2   # 20% in staging
+
+    return 0.1  # 10% default
+
+sentry_sdk.init(
+    dsn="your-dsn",
+    traces_sampler=traces_sampler,
+)
+```
+
+3. Controlling Sampling Based on User and Transaction Properties
+
+```python
+def traces_sampler(sampling_context):
+    ctx = sampling_context.get("transaction_context", {})
+    data = ctx.get("data", {})
+
+    # Always sample for premium users
+    if data.get("user", {}).get("tier") == "premium":
+        return 1.0
+
+    # Sample more transactions for users experiencing errors
+    if data.get("hasRecentErrors"):
+        return 0.8
+
+    # Sample less for high-volume, low-value paths
+    if ctx.get("name", "").startswith("/api/metrics"):
+        return 0.01
+
+    # Sample more for slow transactions
+    if data.get("duration_ms", 0) > 1000:  # Transactions over 1 second
+        return 0.5
+
+    # If there's a parent sampling decision, respect it
+    if sampling_context.get("parent_sampled") is not None:
+        return sampling_context["parent_sampled"]
+
+    # Default sampling rate
+    return 0.2
+
+sentry_sdk.init(
+    dsn="your-dsn",
+    traces_sampler=traces_sampler,
+)
+```
+
+4. Complex Business Logic Sampling
+
+```python
+def traces_sampler(sampling_context):
+    ctx = sampling_context.get("transaction_context", {})
+    data = ctx.get("data", {})
+
+    # Always sample critical business operations
+    if ctx.get("op") in ["payment.process", "order.create", "user.verify"]:
+        return 1.0
+
+    # Sample based on user segment
+    user_segment = data.get("user", {}).get("segment")
+    if user_segment == "enterprise":
+        return 0.8
+    elif user_segment == "premium":
+        return 0.5
+
+    # Sample based on transaction value
+    transaction_value = data.get("transaction", {}).get("value", 0)
+    if transaction_value > 1000:  # High-value transactions
+        return 0.7
+
+    # Sample based on error rate in the service
+    error_rate = data.get("service", {}).get("error_rate", 0)
+    if error_rate > 0.05:  # Error rate above 5%
+        return 0.9
+
+    # Inherit parent sampling decision if available
+    if sampling_context.get("parent_sampled") is not None:
+        return sampling_context["parent_sampled"]
+
+    # Default sampling rate
+    return 0.1
+
+sentry_sdk.init(
+    dsn="your-dsn",
+    traces_sampler=traces_sampler,
+)
+```
+
+5. Performance-Based Sampling
+
+```python
+def traces_sampler(sampling_context):
+    ctx = sampling_context.get("transaction_context", {})
+    data = ctx.get("data", {})
+
+    # Sample all slow transactions
+    if data.get("duration_ms", 0) > 2000:  # Over 2 seconds
+        return 1.0
+
+    # Sample more transactions with high memory usage
+    if data.get("memory_usage_mb", 0) > 500:  # Over 500MB
+        return 0.8
+
+    # Sample more transactions with high CPU usage
+    if data.get("cpu_percent", 0) > 80:  # Over 80% CPU
+        return 0.8
+
+    # Sample more transactions with high database load
+    if data.get("db_connections", 0) > 100:  # Over 100 connections
+        return 0.7
+
+    # Default sampling rate
+    return 0.1
+
+sentry_sdk.init(
+    dsn="your-dsn",
+    traces_sampler=traces_sampler,
+)
+```
+
+## The Sampling Context Object
+
+When the `traces_sampler` function is called, the Sentry SDK  passes a `sampling_context` object with information from the relevant span to help make sampling decisions:
+
+```python
+{
+    "transaction_context": {
+        "name": str,  # transaction title at creation time
+        "op": str,    # short description of transaction type, like "http.request"
+        # other transaction data...
+    },
+    "parent_sampled": bool,  # whether the parent transaction was sampled (if any)
+    "parent_sample_rate": float,  # the sample rate used by the parent (if any)
+    # Custom context as passed to start_transaction
+}
+```
+
+The sampling context contains:
+
+- `transaction_context`: Includes the transaction name, operation type, and other metadata
+- `parent_sampled`: Whether the parent transaction was sampled (for distributed tracing)
+- `parent_sample_rate`: The sample rate used in the parent transaction
+- Any custom sampling context data passed to `start_transaction`
+
+## Inheritance in Distributed Tracing
+
+In distributed systems, trace information is propagated between services. You can implement inheritance logic like this:
+
+```python
+def traces_sampler(sampling_context):
+    # Examine provided context data
+    if "transaction_context" in sampling_context:
+        name = sampling_context["transaction_context"].get("name", "")
+
+        # Apply specific rules first
+        if "critical-path" in name:
+            return 1.0  # Always sample
+
+    # Inherit parent sampling decision if available
+    if sampling_context.get("parent_sampled") is not None:
+        return sampling_context["parent_sampled"]
+
+    # Otherwise use a default rate
+    return 0.1
+```
+
+This approach ensures consistent sampling decisions across your entire distributed trace. All transactions in a given trace will share the same sampling decision, preventing broken or incomplete traces.
+
+## Sampling Decision Precedence
+
+When multiple sampling mechanisms could apply, Sentry follows this order of precedence:
+
+1. If a sampling decision is passed to `start_transaction`, that decision is used
+2. If `traces_sampler` is defined, its decision is used (can consider parent sampling)
+3. If no `traces_sampler` but parent sampling is available, parent decision is used
+4. If neither of the above, `traces_sample_rate` is used
+5. If none of the above are set, no transactions are sampled (0%)
+
+## How Sampling Propagates in Distributed Traces
+
+Sentry uses a "head-based" sampling approach:
+
+- A sampling decision is made in the originating service (the "head")
+- This decision is propagated to all downstream services via HTTP headers
+
+The two key headers are:
+- `sentry-trace`: Contains trace ID, span ID, and sampling decision
+- `baggage`: Contains additional trace metadata including sample rate
+
+The Sentry Python SDK automatically attaches these headers to outgoing HTTP requests when using auto-instrumentation with libraries like `requests`, `urllib3`, or `httpx`. For other communication channels, you can manually propagate trace information:
+
+```python
+# Extract trace data from the current scope
+trace_data = sentry_sdk.get_current_scope().get_trace_context()
+sentry_trace_header = trace_data.get("sentry-trace")
+baggage_header = trace_data.get("baggage")
+
+# Add to your custom request (example using a message queue)
+message = {
+    "data": "Your data here",
+    "metadata": {
+        "sentry_trace": sentry_trace_header,
+        "baggage": baggage_header
+    }
+}
+queue.send(json.dumps(message))
+```
+
+By implementing a thoughtful sampling strategy, you'll get the performance insights you need without overwhelming your systems or your Sentry quota.

docs/platforms/python/tracing/trace-propagation/index.mdx → docs/platforms/python/tracing/distributed-tracing/index.mdx

@@ -1,10 +1,10 @@
 ---
-title: Trace Propagation
+title: Set Up Distributed Tracing
 description: "Learn how to connect events across applications/services."
-sidebar_order: 3000
+sidebar_order: 20
 ---
 
-If the overall application landscape that you want to observe with Sentry consists of more than just a single service or application, distributed tracing can add a lot of value.
+<PlatformContent includePath="distributed-tracing/explanation" />
 
 ## What is Distributed Tracing?