(#5849) Convert rst to markdown (#6040)

Converting some of the rst documentation to markdown.  Attempted to
preserve whitespace and line breaks to minimize cosmetic change.

1 files changed, 0 insertions, 123 deletions

diff --git a/docs/opentracing.rst b/docs/opentracing.rst
deleted file mode 100644
index 6e98ab56ba..0000000000
--- a/docs/opentracing.rst
+++ /dev/null
@@ -1,123 +0,0 @@
-===========
-OpenTracing
-===========
-
-Background
-----------
-
-OpenTracing is a semi-standard being adopted by a number of distributed tracing
-platforms. It is a common api for facilitating vendor-agnostic tracing
-instrumentation. That is, we can use the OpenTracing api and select one of a
-number of tracer implementations to do the heavy lifting in the background.
-Our current selected implementation is Jaeger.
-
-OpenTracing is a tool which gives an insight into the causal relationship of
-work done in and between servers. The servers each track events and report them
-to a centralised server - in Synapse's case: Jaeger. The basic unit used to
-represent events is the span. The span roughly represents a single piece of work
-that was done and the time at which it occurred. A span can have child spans,
-meaning that the work of the child had to be completed for the parent span to
-complete, or it can have follow-on spans which represent work that is undertaken
-as a result of the parent but is not depended on by the parent to in order to
-finish.
-
-Since this is undertaken in a distributed environment a request to another
-server, such as an RPC or a simple GET, can be considered a span (a unit or
-work) for the local server. This causal link is what OpenTracing aims to
-capture and visualise. In order to do this metadata about the local server's
-span, i.e the 'span context', needs to be included with the request to the
-remote.
-
-It is up to the remote server to decide what it does with the spans
-it creates. This is called the sampling policy and it can be configured
-through Jaeger's settings.
-
-For OpenTracing concepts see
-https://opentracing.io/docs/overview/what-is-tracing/.
-
-For more information about Jaeger's implementation see
-https://www.jaegertracing.io/docs/
-
-=====================
-Seting up OpenTracing
-=====================
-
-To receive OpenTracing spans, start up a Jaeger server. This can be done
-using docker like so:
-
-.. code-block:: bash
-
-   docker run -d --name jaeger
-     -p 6831:6831/udp \
-     -p 6832:6832/udp \
-     -p 5778:5778 \
-     -p 16686:16686 \
-     -p 14268:14268 \
-     jaegertracing/all-in-one:1.13
-
-Latest documentation is probably at
-https://www.jaegertracing.io/docs/1.13/getting-started/
-
-
-Enable OpenTracing in Synapse
------------------------------
-
-OpenTracing is not enabled by default. It must be enabled in the homeserver
-config by uncommenting the config options under ``opentracing`` as shown in
-the `sample config <./sample_config.yaml>`_. For example:
-
-.. code-block:: yaml
-
-  opentracing:
-    tracer_enabled: true
-    homeserver_whitelist:
-      - "mytrustedhomeserver.org"
-      - "*.myotherhomeservers.com"
-
-Homeserver whitelisting
------------------------
-
-The homeserver whitelist is configured using regular expressions. A list of regular
-expressions can be given and their union will be compared when propagating any
-spans contexts to another homeserver.
-
-Though it's mostly safe to send and receive span contexts to and from
-untrusted users since span contexts are usually opaque ids it can lead to
-two problems, namely:
-
-- If the span context is marked as sampled by the sending homeserver the receiver will
-  sample it. Therefore two homeservers with wildly different sampling policies
-  could incur higher sampling counts than intended.
-- Sending servers can attach arbitrary data to spans, known as 'baggage'. For safety this has been disabled in Synapse
-  but that doesn't prevent another server sending you baggage which will be logged
-  to OpenTracing's logs.
-
-==========
-EDU FORMAT
-==========
-
-EDUs can contain tracing data in their content. This is not specced but
-it could be of interest for other homeservers.
-
-EDU format (if you're using jaeger):
-
-.. code-block:: json
-
-   {
-     "edu_type": "type",
-     "content": {
-       "org.matrix.opentracing_context": {
-         "uber-trace-id": "fe57cf3e65083289"
-       }
-     }
-   }
-
-Though you don't have to use jaeger you must inject the span context into
-`org.matrix.opentracing_context` using the opentracing `Format.TEXT_MAP` inject method.
-
-==================
-Configuring Jaeger
-==================
-
-Sampling strategies can be set as in this document:
-https://www.jaegertracing.io/docs/1.13/sampling/