Generating custom subsegments with the X-Ray SDK for Python
Subsegments extend a trace's segment with details about work done in order to serve a request. Each time you make a call with an instrumented client, the X-Ray SDK records the information generated in a subsegment. You can create additional subsegments to group other subsegments, to measure the performance of a section of code, or to record annotations and metadata.
To manage subsegments, use the begin_subsegment and end_subsegment methods.
Example main.py – Custom subsegment
from aws_xray_sdk.core import xray_recorder
subsegment = xray_recorder.begin_subsegment('annotations')
subsegment.put_annotation('id', 12345)
xray_recorder.end_subsegment()To create a subsegment for a synchronous function, use the
@xray_recorder.capture decorator. You can pass a name for the subsegment to the
capture function or leave it out to use the function name.
Example main.py – Function subsegment
from aws_xray_sdk.core import xray_recorder
@xray_recorder.capture('## create_user')
def create_user():
...For an asynchronous function, use the @xray_recorder.capture_async decorator,
and pass an async context to the recorder.
Example main.py – Asynchronous function subsegment
from aws_xray_sdk.core.async_context import AsyncContext
from aws_xray_sdk.core import xray_recorder
xray_recorder.configure(service='my_service', context=AsyncContext())
@xray_recorder.capture_async('## create_user')
async def create_user():
...
async def main():
await myfunc()When you create a subsegment within a segment or another subsegment, the X-Ray SDK for Python generates an ID for it and records the start time and end time.
Example Subsegment with metadata
"subsegments": [{
"id": "6f1605cd8a07cb70",
"start_time": 1.480305974194E9,
"end_time": 1.4803059742E9,
"name": "Custom subsegment for UserModel.saveUser function",
"metadata": {
"debug": {
"test": "Metadata string from UserModel.saveUser"
}
},