[hotfix][doc] Add note on how to use custom loggers with a per-job-yarn cluster

docs/_local_preview_conf.yml

+# 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.
+
+# We unset the baseurl for local testing
+baseurl: ""

docs/apis/best_practices.md

@@ -279,7 +279,7 @@ Apache Flink is using [slf4j](http://www.slf4j.org/) as the logging abstraction
 
 Sfl4j is a compile-time logging interface that can use different logging implementations at runtime, such as [log4j](http://logging.apache.org/log4j/2.x/) or [Logback](http://logback.qos.ch/).
 
-Flink is depending on Log4j by default. This page describes how to use Flink with Logback.
+Flink is depending on Log4j by default. This page describes how to use Flink with Logback. Users reported that they were also able to set up centralized logging with Graylog using this tutorial.
 
 To get a logger instance in the code, use the following code:
 
@@ -397,3 +397,7 @@ Next, you need to put the following jar files into the `lib/` folder:
  * `logback-classic.jar`
  * `logback-core.jar`
  * `log4j-over-slf4j.jar`: This bridge needs to be present in the classpath for redirecting logging calls from Hadoop (which is using Log4j) to Slf4j.
+
+Note that you need to explicitly set the `lib/` directory when using a per job YARN cluster.
+
+The command to submit Flink on YARN with a custom logger is: `./bin/flink run -yt $FLINK_HOME/lib <... remaining arguments ...>`

docs/build_docs.sh

@@ -54,7 +54,7 @@ JEKYLL_CMD="build"
 while getopts ":p" opt; do
 	case $opt in
 		p)
-		JEKYLL_CMD="serve --baseurl "" --watch"
+		JEKYLL_CMD="serve --config _config.yml,_local_preview_conf.yml --watch"
 		;;
 	esac
 done