Strip number suffix from instance name to consolidate services that traces are spread over (#13729)

The problem with many services is that it makes it hard to find which service has the trace you want, see https://github.com/jaegertracing/jaeger-ui/issues/985

Previously, we split traces out into services based on their instance name like `matrix.org client_reader-1`, etc but there are many worker instances of the same `client_reader` so there is a lot to click through.

With this PR, all of the traces are just collected under the worker type like `client_reader`, `event_persister` 😇

Note: A Synapse worker instance name is an opaque string with the number convention only being our own thing for the `matrix.org` deployment. But seems pretty sensible to group things this way.
This commit is contained in:
Eric Eastwood 2022-09-09 11:30:06 -05:00 committed by GitHub
parent 3d9f82efcb
commit f694bb71b7
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2 changed files with 13 additions and 1 deletions

1
changelog.d/13729.misc Normal file
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@ -0,0 +1 @@
Strip number suffix from instance name to consolidate services that traces are spread over.

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@ -203,6 +203,9 @@ if TYPE_CHECKING:
# Helper class
# Matches the number suffix in an instance name like "matrix.org client_reader-8"
STRIP_INSTANCE_NUMBER_SUFFIX_REGEX = re.compile(r"[_-]?\d+$")
class _DummyTagNames:
"""wrapper of opentracings tags. We need to have them if we
@ -441,9 +444,17 @@ def init_tracer(hs: "HomeServer") -> None:
from jaeger_client.metrics.prometheus import PrometheusMetricsFactory
# Instance names are opaque strings but by stripping off the number suffix,
# we can get something that looks like a "worker type", e.g.
# "client_reader-1" -> "client_reader" so we don't spread the traces across
# so many services.
instance_name_by_type = re.sub(
STRIP_INSTANCE_NUMBER_SUFFIX_REGEX, "", hs.get_instance_name()
)
config = JaegerConfig(
config=hs.config.tracing.jaeger_config,
service_name=f"{hs.config.server.server_name} {hs.get_instance_name()}",
service_name=f"{hs.config.server.server_name} {instance_name_by_type}",
scope_manager=LogContextScopeManager(),
metrics_factory=PrometheusMetricsFactory(),
)