commit

solr/modules/jaegertracer-configurator/README.md

@@ -0,0 +1,48 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+
+Welcome to Apache Solr Jaeger Tracer Configurator
+========
+
+**WARNING**: This module is deprecated for removal in v10.0.
+
+Apache Solr Jaeger Tracer Configurator provides a way for you to expose Solr's tracing to Jaeger.
+
+# Setup Jaeger Tracer Configurator
+
+Add this Solr Module to your Solr installation by enabling it via `-Dsolr.modules=jaegertracer-configurator`
+
+There are a number of sampler's available to Jaeger.  Learn more about the available samplers at https://www.jaegertracing.io/docs/sampling/#client-sampling-configuration.
+
+The Jaeger Tracer Configurator is added to `solr.xml` like this:
+
+```
+<tracerConfig name="tracerConfig" class="org.apache.solr.jaeger.JaegerTracerConfigurator" />
+```
+
+There are no configuration elements in the XML; instead, this 3rd party system is configured using System Properties or Environment Variables.  The full list are listed at [Jaeger-README](https://github.com/jaegertracing/jaeger-client-java/blob/master/jaeger-core/README.md).
+For example, to use the probabilistic sampler, you could set this environment variable:
+
+```
+export JAEGER_SAMPLER_TYPE=probabilistic
+```
+
+or System property:
+
+```
+bin/solr start -DJAEGER_SAMPLER_TYPE=probabilistic
+```