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Make English in jaegertracing/index.rst more elegant. Signed-off-by: Zac Dover <zac.dover@gmail.com>
108 lines
3.1 KiB
ReStructuredText
108 lines
3.1 KiB
ReStructuredText
JAEGER- DISTRIBUTED TRACING
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===========================
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Jaeger provides ready-to-use tracing services for distributed systems.
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BASIC ARCHITECTURE AND TERMINOLOGY
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----------------------------------
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* TRACE: A trace shows the data/execution path through a system.
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* SPAN: A single unit of a trace. A data structure that stores information such
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as the operation name, timestamps, and the ordering within a trace.
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* JAEGER CLIENT: Language-specific implementations of the OpenTracing API.
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* JAEGER AGENT: A daemon that listens for spans sent over User Datagram
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Protocol. The agent is meant to be placed on the same host as the
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instrumented application. (The Jaeger agent acts like a sidecar listener.)
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* JAEGER COLLECTOR: A daemon that receives spans sent by the Jaeger agent. The
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Jaeger collector then stitches the spans together to form a trace. (A databse
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can be enabled to persist a database for these traces).
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* JAEGER QUERY AND CONSOLE FRONTEND: The UI-based frontend that presents
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reports of the jaeger traces. Accessible at http://<jaeger frontend host>:16686.
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Read more about jaeger tracing:.
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https://www.jaegertracing.io/docs/
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JAEGER DEPLOYMENT
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-----------------
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Jaeger can be deployed using cephadm, and Jaeger can be deployed manually.
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Refer to one of the following:
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`Cephadm Jaeger Services Deployment <../cephadm/services/tracing/>`_
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`Jaeger Deployment <https://www.jaegertracing.io/docs/1.25/deployment/>`_
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`Jaeger Performance Tuning <https://www.jaegertracing.io/docs/1.25/performance-tuning/>`_
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Important Notes:
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^^^^^^^^^^^^^^^^
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- The Jaeger agent must be running on each host (and not running in all-in-one
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mode). This is because spans are sent to the local Jaeger agent. Spans of
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hosts that do not have active Jaeger agents will be lost.
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- Ceph tracers are configured to send tracers to agents that listen to port
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6799. Use the option "--processor.jaeger-compact.server-host-port=6799" for
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manual Jaeger deployments.
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HOW TO ENABLE TRACING IN CEPH
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-----------------------------
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Tracing in Ceph is disabled by default.
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Tracing can be enabled globally, and tracing can also be enabled separately for
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each entity (for example, for rgw).
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Enable tracing globally:
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.. prompt:: bash $
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ceph config set global jaeger_tracing_enable true
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Enable tracing for each entity:
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.. prompt:: bash $
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ceph config set <entity> jaeger_tracing_enable true
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TRACES IN RGW
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-------------
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Traces run on RGW can be found under the Service `rgw` in the Jaeger Frontend.
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REQUESTS
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^^^^^^^^
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Every user request is traced. Each trace contains tags for `Operation name`,
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`User id`, `Object name` and `Bucket name`.
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There is also an `Upload id` tag for Multipart upload operations.
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The names of request traces have the following format: `<command> <transaction
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id>`.
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MULTIPART UPLOAD
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^^^^^^^^^^^^^^^^
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There is a kind of trace that consists of a span for each request made by a
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multipart upload, and it includes all `Put Object` requests.
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The names of multipart traces have the following format: `multipart_upload
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<upload id>`.
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rgw service in Jaeger Frontend:
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.. image:: ./rgw_jaeger.png
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:width: 400
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osd service in Jaeger Frontend:
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.. image:: ./osd_jaeger.png
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:width: 400
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