mirror of
https://github.com/ceph/ceph
synced 2024-12-12 06:28:31 +00:00
75 lines
3.1 KiB
ReStructuredText
75 lines
3.1 KiB
ReStructuredText
|
JAEGER- DISTRIBUTED TRACING
|
||
|
|
===========================
|
||
|
|
|
||
|
|
Jaeger + Opentracing provides ready to use tracing services for distributed
|
||
|
|
systems and is becoming the widely used standard because of their simplicity and
|
||
|
|
standardization.
|
||
|
|
|
||
|
|
We use a modified `jaeger-cpp-client
|
||
|
|
<https://github.com/ceph/jaeger-client-cpp>`_ the backend provided to the
|
||
|
|
Opentracing API, which is responsible for the collection of spans, these spans
|
||
|
|
are made with the use of smart pointers that carry the timestamp, TraceID and other
|
||
|
|
meta info like a specific tag/log associated with the span to uniquely identify
|
||
|
|
it across the distributed system.
|
||
|
|
|
||
|
|
|
||
|
|
BASIC ARCHITECTURE AND TERMINOLOGY
|
||
|
|
----------------------------------
|
||
|
|
|
||
|
|
* TRACE: A trace shows the data/execution path through a system.
|
||
|
|
* SPAN: A single unit of a trace, it is a data structure that stores
|
||
|
|
information like operation name, timestamps, ordering in a trace.
|
||
|
|
* JAEGER CLIENT: language-specific implementations of the OpenTracing API.
|
||
|
|
* JAEGER AGENT: a daemon that listens for spans sent over User Datagram Protocol.
|
||
|
|
The agent is meant to be placed on the same host as the instrumented
|
||
|
|
application. (acts like a sidecar listener)
|
||
|
|
* JAEGER COLLECTOR: Jaeger agent sends the spans to this daemon which then
|
||
|
|
stitches the spans together to form a trace(if enabled, also persists a database
|
||
|
|
for these traces)
|
||
|
|
* JAEGER QUERY AND CONSOLE FRONTEND: UI based frontend to checkout the jaeger
|
||
|
|
traces, navigate to http://localhost:16686 (if using default `all-in-one
|
||
|
|
docker <https://www.jaegertracing.io/docs/1.22/getting-started/#all-in-one>`_ to access the Jaeger UI.
|
||
|
|
|
||
|
|
HOW TO GET STARTED USING TRACING?
|
||
|
|
---------------------------------
|
||
|
|
|
||
|
|
Enabling jaegertracing with Ceph needs deployment Jaeger daemons + compiling
|
||
|
|
Ceph with Jaeger, orchestrated to be used in vstart cluster for developers, this
|
||
|
|
uses a jaeger `all-in-one docker
|
||
|
|
<https://www.jaegertracing.io/docs/1.22/getting-started/#all-in-one>`_ which
|
||
|
|
isn't recommended for production, but for testing purposes. Let's look at all the
|
||
|
|
steps needed:
|
||
|
|
|
||
|
|
1. Update system with Jaeger dependencies, using install-deps::
|
||
|
|
|
||
|
|
$ WITH_JAEGER=true ./install-deps.sh
|
||
|
|
|
||
|
|
2. Compile Ceph with Jaeger enabled:
|
||
|
|
|
||
|
|
- for precompiled build::
|
||
|
|
|
||
|
|
$ cd build
|
||
|
|
$ cmake -DWITH_JAEGER=ON ..
|
||
|
|
|
||
|
|
- for fresh compilation using do_cmake.sh::
|
||
|
|
|
||
|
|
$ ./do_cmake.sh -DWITH_JAEGER=ON && ninja vstart
|
||
|
|
|
||
|
|
3. After successful compiling, start a vstart cluster with `--jaeger` which
|
||
|
|
will deploy `jaeger all-in-one <https://www.jaegertracing.io/docs/1.20/getting-started/#all-in-one>`_
|
||
|
|
using container deployment services(docker/podman)::
|
||
|
|
|
||
|
|
$ MON=1 MGR=0 OSD=1 ../src/vstart.sh --with-jaeger
|
||
|
|
|
||
|
|
if the deployment is unsuccessful, you can deploy `all-in-one
|
||
|
|
<https://www.jaegertracing.io/docs/1.20/getting- started/#all-in-one>`_
|
||
|
|
service manually and start vstart cluster without jaeger as well.
|
||
|
|
|
||
|
|
|
||
|
|
4. Test the traces using rados-bench write::
|
||
|
|
|
||
|
|
$ bin/rados -p test bench 5 write --no-cleanup
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
`using-jaeger-cpp-client-for-distributed-tracing-in-ceph <https://medium.com/@deepikaupadhyay/using-jaeger-cpp-client-for-distributed-tracing-in-ceph-8b1f4906ca2>`_
|