druid/dev/intellij-setup.md

<!--
  ~ 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.
  -->

# IntelliJ Setup
This document contains some examples and instructions on how to get IntelliJ setup to run local debugging and test
setups of Druid.

## Project SDK

The "SDK", configured for the Druid project, *must* be called `1.8`, to avoid annoying changes of
[.idea/misc.xml](`.idea/misc.xml`) file, that you shouldn't check into your commits. If you don't have an SDK on your
dev machine with this name, you should either rename one of the existing SDKs to `1.8`, or create another one with this
name, and it could point to the same files as some other existing SDK, even if it's actually JDK 9+. `1.8` is just
an alias name. You can do this in Using `File` -> `Project Structure...` -> `Platform Settings` -> `SDKs`
(see also [IntelliJ help page about this](https://www.jetbrains.com/help/idea/configuring-intellij-platform-plugin-sdk.html)):
![IntelliJ SDK Config](intellij-sdk-config.jpg)

## Code Style
The Code Style is available in XML format at [druid_intellij_formatting.xml](druid_intellij_formatting.xml) and can be [imported into IntelliJ](https://www.jetbrains.com/help/idea/2017.1/copying-code-style-settings.html).

## Metadata
The installation of a MySQL metadata store is outside the scope of this document, but instructions on setting up MySQL can be found at [docs/development/extensions-core/mysql.md](/docs/development/extensions-core/mysql.md). This assumes you followed the example there and have a database named `druid` with proper permissions for a user named `druid` and a password of `diurd`.

Use of other databases such as Postgres or Derby are entirely reasonable, but doing so is left as an excercise to the reader.

## ZooKeeper
This also assumes you have [ZooKeeper](http://zookeeper.apache.org/releases.html) running locally, which usually just involves downloading the latst distribution of ZooKeeper, doing some minor configuration in ZooKeeper's `conf/` directory (most defaults are fine), then running `./bin/zkServer.sh start` in the ZooKeeper directory. 

## Initial Build
Before running the apps, you should do a `mvn clean install -DskipTests` in the Druid source in order to make sure directories are populated correctly.

## XML App Def
You can configure application definitions in XML for import into IntelliJ. Below are a few examples. These should be placed in an XML file in [.idea/runConfigurations](.idea/runConfigurations) in the Druid source code.

### Historical.xml
```xml
<component name="ProjectRunConfigurationManager">
  <configuration default="false" name="Historical" type="Application" factoryName="Application">
    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
    <option name="MAIN_CLASS_NAME" value="org.apache.druid.cli.Main" />
    <option name="VM_PARAMETERS" value="-server -Duser.timezone=UTC -Dfile.encoding=UTF-8 -Xmx2G -XX:MaxJavaStackTraceDepth=9999 -XX:+UseG1GC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintAdaptiveSizePolicy -XX:+PrintReferenceGC -verbose:gc -XX:+PrintFlagsFinal -Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager -Dorg.jboss.logging.provider=slf4j -Dlog4j.configurationFile=$PROJECT_DIR$/core/src/main/resources/log4j2.debug.xml -Ddruid.host=localhost -Ddruid.service=historical -Ddruid.server.maxSize=10000000000 -Ddruid.processing.buffer.sizeBytes=100000000 -Ddruid.extensions.hadoopDependenciesDir=$PROJECT_DIR$/distribution/target/hadoop-dependencies/ -Ddruid.extensions.directory=$PROJECT_DIR$/distribution/target/extensions/ -Ddruid.extensions.loadList=[\&quot;druid-s3-extensions\&quot;,\&quot;druid-histogram\&quot;,\&quot;mysql-metadata-storage\&quot;] -Ddruid.historical.cache.useCache=false -Ddruid.historical.cache.populateCache=false -Ddruid.segmentCache.locations=&quot;[{\&quot;path\&quot;:\&quot;/tmp/druid/indexCache\&quot;,\&quot;maxSize\&quot;:10000000000}]&quot; -Ddruid.zk.service.host=localhost -Ddruid.processing.numThreads=1 -Ddruid.server.http.numThreads=50 -Ddruid.serverview.type=batch -Ddruid.emitter=logging" />
    <option name="PROGRAM_PARAMETERS" value="server historical" />
    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$" />
    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
    <option name="ALTERNATIVE_JRE_PATH" value="1.8" />
    <option name="ENABLE_SWING_INSPECTOR" value="false" />
    <option name="ENV_VARIABLES" />
    <option name="PASS_PARENT_ENVS" value="true" />
    <module name="druid-services" />
    <envs />
    <method />
  </configuration>
</component>
```

### Coordinator.xml
```xml
<component name="ProjectRunConfigurationManager">
  <configuration default="false" name="Coordinator" type="Application" factoryName="Application">
    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
    <option name="MAIN_CLASS_NAME" value="org.apache.druid.cli.Main" />
    <option name="VM_PARAMETERS" value="-server -Duser.timezone=UTC -Dfile.encoding=UTF-8 -Xmx256M -Xmx256M -XX:+UseG1GC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintAdaptiveSizePolicy -XX:+PrintReferenceGC -verbose:gc -XX:+PrintFlagsFinal -Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager -Dorg.jboss.logging.provider=slf4j -Ddruid.host=localhost -Ddruid.service=coordinator -Ddruid.extensions.directory=$PROJECT_DIR$/distribution/target/extensions/ -Ddruid.extensions.loadList=[\&quot;druid-s3-extensions\&quot;,\&quot;druid-histogram\&quot;,\&quot;mysql-metadata-storage\&quot;] -Ddruid.zk.service.host=localhost -Ddruid.metadata.storage.type=mysql -Ddruid.metadata.storage.connector.connectURI=&quot;jdbc:mysql://localhost:3306/druid&quot; -Ddruid.metadata.storage.connector.user=druid -Ddruid.metadata.storage.connector.password=diurd -Ddruid.serverview.type=batch -Ddruid.emitter=logging -Ddruid.coordinator.period=PT10S -Ddruid.coordinator.startDelay=PT5S" />
    <option name="PROGRAM_PARAMETERS" value="server coordinator" />
    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$" />
    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
    <option name="ALTERNATIVE_JRE_PATH" value="1.8" />
    <option name="ENABLE_SWING_INSPECTOR" value="false" />
    <option name="ENV_VARIABLES" />
    <option name="PASS_PARENT_ENVS" value="true" />
    <module name="druid-services" />
    <envs />
    <method />
  </configuration>
</component>
```