sthetland commented on a change in pull request #11463:
URL: https://github.com/apache/druid/pull/11463#discussion_r682706555



##########
File path: docs/tutorials/docker.md
##########
@@ -21,67 +21,108 @@ title: "Docker"
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-  
+
 In this quickstart, we will download the Apache Druid image from [Docker 
Hub](https://hub.docker.com/r/apache/druid) and set it up on a single machine 
using [Docker](https://www.docker.com/get-started) and [Docker 
Compose](https://docs.docker.com/compose/). The cluster will be ready to load 
data after completing this initial setup.
 
-Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with Docker is recommended.
+Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with 
[Docker](https://www.docker.com/get-started) is recommended.
+
+This tutorial assumes you will download the required files from GitHub. The 
files are also available in a Druid installation and in the Druid sources.
 
 ## Prerequisites
 
-* Docker
+* [Docker](https://www.docker.com/get-started)
 
 ## Getting started
 
-The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which can pull an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments.
+Create a directory to hold the Druid Docker files.
+
+The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which pulls an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 this file to the directory created above.
 
 ### Compose file
 
-The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store. 
+The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store.
 
-It will also create a named volumes `druid_shared`, which is mounted as 
`opt/shared` in container, as deep storage to keep and share segments and task 
logs among Druid services.
+It will also create a named volume `druid_shared` as deep storage to keep and 
share segments and task logs among Druid services. The volume is mounted as 
`opt/shared` in the container.
 
-The Druid containers are configured via an [environment 
file](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment).
+### Environment file
+
+The Druid `docker-compose.yml` example utilizes an [environment 
file](https://docs.docker.com/compose/environment-variables/#the-env_file-configuration-option)
 to specify the complete Druid configuration, including the environment 
variables listed below. This file is named `environment` by default, and must 
be in the same directory as the `docker-compose.yml` file. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/environment)
 the example `environment` file to the directory created above. The options in 
this file work well for trying Druid and for using the tutorial.
+
+The single-file approach is inadequate for a production system. Instead we 
suggest using either `DRUID_COMMON_CONFIG` and `DRUID_CONFIG_${service}` or 
specially tailored, service-specific environment files.
 
 ### Configuration
 
-Configuration of the Druid Docker container is done via environment variables, 
which may additionally specify paths to [the standard Druid configuration 
files](../configuration/index.md)
+Configuration of the Druid Docker container is done via environment variables 
set within the container. Docker Compose passes the values from the 
`environment file` into the container. The variables may additionally specify 
paths to [the standard Druid configuration files](../configuration/index.md) 
which must be available within the container.
+
+The default values are fine for the Quickstart. Production systems will want 
to modify the defaults.
 
-Special environment variables:
+Basic configuration:
+
+* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size. Default is 6 
GB.
+* `DRUID_XMX` -- set Java `Xmx`, the maximum heap size. Default is 1 GB.
+
+Production configuration:
 
-* `JAVA_OPTS` -- set java options
-* `DRUID_LOG4J` -- set the entire `log4j.xml` verbatim
-* `DRUID_LOG_LEVEL` -- override the default log level in default log4j
-* `DRUID_XMX` -- set Java `Xmx`
-* `DRUID_XMS` -- set Java `Xms`
-* `DRUID_MAXNEWSIZE` -- set Java max new size
-* `DRUID_NEWSIZE` -- set Java new size
-* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size
 * `DRUID_CONFIG_COMMON` -- full path to a file for druid 'common' properties

Review comment:
       ```suggestion
   * `DRUID_CONFIG_COMMON` -- full path to a file for Druid common properties
   ```

##########
File path: docs/tutorials/docker.md
##########
@@ -21,67 +21,108 @@ title: "Docker"
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-  
+
 In this quickstart, we will download the Apache Druid image from [Docker 
Hub](https://hub.docker.com/r/apache/druid) and set it up on a single machine 
using [Docker](https://www.docker.com/get-started) and [Docker 
Compose](https://docs.docker.com/compose/). The cluster will be ready to load 
data after completing this initial setup.
 
-Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with Docker is recommended.
+Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with 
[Docker](https://www.docker.com/get-started) is recommended.
+
+This tutorial assumes you will download the required files from GitHub. The 
files are also available in a Druid installation and in the Druid sources.
 
 ## Prerequisites
 
-* Docker
+* [Docker](https://www.docker.com/get-started)
 
 ## Getting started
 
-The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which can pull an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments.
+Create a directory to hold the Druid Docker files.
+
+The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which pulls an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 this file to the directory created above.
 
 ### Compose file
 
-The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store. 
+The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store.
 
-It will also create a named volumes `druid_shared`, which is mounted as 
`opt/shared` in container, as deep storage to keep and share segments and task 
logs among Druid services.
+It will also create a named volume `druid_shared` as deep storage to keep and 
share segments and task logs among Druid services. The volume is mounted as 
`opt/shared` in the container.
 
-The Druid containers are configured via an [environment 
file](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment).
+### Environment file
+
+The Druid `docker-compose.yml` example utilizes an [environment 
file](https://docs.docker.com/compose/environment-variables/#the-env_file-configuration-option)
 to specify the complete Druid configuration, including the environment 
variables listed below. This file is named `environment` by default, and must 
be in the same directory as the `docker-compose.yml` file. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/environment)
 the example `environment` file to the directory created above. The options in 
this file work well for trying Druid and for using the tutorial.
+
+The single-file approach is inadequate for a production system. Instead we 
suggest using either `DRUID_COMMON_CONFIG` and `DRUID_CONFIG_${service}` or 
specially tailored, service-specific environment files.
 
 ### Configuration
 
-Configuration of the Druid Docker container is done via environment variables, 
which may additionally specify paths to [the standard Druid configuration 
files](../configuration/index.md)
+Configuration of the Druid Docker container is done via environment variables 
set within the container. Docker Compose passes the values from the 
`environment file` into the container. The variables may additionally specify 
paths to [the standard Druid configuration files](../configuration/index.md) 
which must be available within the container.
+
+The default values are fine for the Quickstart. Production systems will want 
to modify the defaults.
 
-Special environment variables:
+Basic configuration:
+
+* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size. Default is 6 
GB.
+* `DRUID_XMX` -- set Java `Xmx`, the maximum heap size. Default is 1 GB.
+
+Production configuration:
 
-* `JAVA_OPTS` -- set java options
-* `DRUID_LOG4J` -- set the entire `log4j.xml` verbatim
-* `DRUID_LOG_LEVEL` -- override the default log level in default log4j
-* `DRUID_XMX` -- set Java `Xmx`
-* `DRUID_XMS` -- set Java `Xms`
-* `DRUID_MAXNEWSIZE` -- set Java max new size
-* `DRUID_NEWSIZE` -- set Java new size
-* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size
 * `DRUID_CONFIG_COMMON` -- full path to a file for druid 'common' properties
 * `DRUID_CONFIG_${service}` -- full path to a file for druid 'service' 
properties
+* `JAVA_OPTS` -- set Java options
+
+Logging configuration:
+
+* `DRUID_LOG4J` -- set the entire [`log4j.xml` configuration 
file](https://logging.apache.org/log4j/2.x/manual/configuration.html#XML)  
verbatim. 
([Example](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment#L52))
+* `DRUID_LOG_LEVEL` -- override the default [Log4j log 
level](https://en.wikipedia.org/wiki/Log4j#Log4j_log_levels)
+
+Advanced memory configuration:
+
+* `DRUID_XMS` -- set Java 
[`Xms`](https://docs.oracle.com/cd/E19900-01/819-4742/abeik/index.html), the 
initial heap size. Default is 1 GB.
+* `DRUID_MAXNEWSIZE` -- set [Java max new 
size](https://docs.oracle.com/cd/E19900-01/819-4742/abeik/index.html)
+* `DRUID_NEWSIZE` -- set [Java new 
size](https://docs.oracle.com/cd/E19900-01/819-4742/abeik/index.html)
 
-In addition to the special environment variables, the script which launches 
Druid in the container will also attempt to use any environment variable 
starting with the `druid_` prefix as a command-line configuration. For example, 
an environment variable
- 
-```druid_metadata_storage_type=postgresql```
- 
-would be translated into 
+In addition to the special environment variables, the script which launches 
Druid in the container will use any environment variable starting with the 
`druid_` prefix as command-line configuration. For example, an environment 
variable
 
-```-Ddruid.metadata.storage.type=postgresql```
- 
-for the Druid process in the container.
+`druid_metadata_storage_type=postgresql`
+
+is translated into the following option in the Java launch command for the 
Druid process in the container:
+
+`-Ddruid.metadata.storage.type=postgresql`
+
+Note that Druid uses port 8888 for the console. This port is also used by 
Jupyter and other tools. To avoid conflicts, you can change the port in the 
[ports](https://github.com/apache/druid/blob/0.21.1/distribution/docker/docker-compose.yml#L125)
 section of the `docker-compose.yml` file. Example to expose the Console on 
port 9999 of the host:

Review comment:
       ```suggestion
   Note that Druid uses port 8888 for the console. This port is also used by 
Jupyter and other tools. To avoid conflicts, you can change the port in the 
[`ports`](https://github.com/apache/druid/blob/0.21.1/distribution/docker/docker-compose.yml#L125)
 section of the `docker-compose.yml` file. For example, to expose the console 
on port 9999 of the host:
   ```

##########
File path: docs/tutorials/docker.md
##########
@@ -21,67 +21,108 @@ title: "Docker"
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-  
+
 In this quickstart, we will download the Apache Druid image from [Docker 
Hub](https://hub.docker.com/r/apache/druid) and set it up on a single machine 
using [Docker](https://www.docker.com/get-started) and [Docker 
Compose](https://docs.docker.com/compose/). The cluster will be ready to load 
data after completing this initial setup.
 
-Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with Docker is recommended.
+Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with 
[Docker](https://www.docker.com/get-started) is recommended.
+
+This tutorial assumes you will download the required files from GitHub. The 
files are also available in a Druid installation and in the Druid sources.
 
 ## Prerequisites
 
-* Docker
+* [Docker](https://www.docker.com/get-started)
 
 ## Getting started
 
-The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which can pull an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments.
+Create a directory to hold the Druid Docker files.
+
+The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which pulls an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 this file to the directory created above.
 
 ### Compose file
 
-The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store. 
+The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store.
 
-It will also create a named volumes `druid_shared`, which is mounted as 
`opt/shared` in container, as deep storage to keep and share segments and task 
logs among Druid services.
+It will also create a named volume `druid_shared` as deep storage to keep and 
share segments and task logs among Druid services. The volume is mounted as 
`opt/shared` in the container.
 
-The Druid containers are configured via an [environment 
file](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment).
+### Environment file
+
+The Druid `docker-compose.yml` example utilizes an [environment 
file](https://docs.docker.com/compose/environment-variables/#the-env_file-configuration-option)
 to specify the complete Druid configuration, including the environment 
variables listed below. This file is named `environment` by default, and must 
be in the same directory as the `docker-compose.yml` file. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/environment)
 the example `environment` file to the directory created above. The options in 
this file work well for trying Druid and for using the tutorial.
+
+The single-file approach is inadequate for a production system. Instead we 
suggest using either `DRUID_COMMON_CONFIG` and `DRUID_CONFIG_${service}` or 
specially tailored, service-specific environment files.
 
 ### Configuration
 
-Configuration of the Druid Docker container is done via environment variables, 
which may additionally specify paths to [the standard Druid configuration 
files](../configuration/index.md)
+Configuration of the Druid Docker container is done via environment variables 
set within the container. Docker Compose passes the values from the 
`environment file` into the container. The variables may additionally specify 
paths to [the standard Druid configuration files](../configuration/index.md) 
which must be available within the container.
+
+The default values are fine for the Quickstart. Production systems will want 
to modify the defaults.
 
-Special environment variables:
+Basic configuration:
+
+* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size. Default is 6 
GB.

Review comment:
       About "6 GB"... a recently merged PR 
(https://github.com/apache/druid/pull/11333) updated the docs to distinguish 
between decimal format and binary format for all size notations. Just to 
confirm, looks like these values should indeed be in Decimal format based on 
the docker config, if I'm reading the config file correctly?  

##########
File path: docs/tutorials/docker.md
##########
@@ -21,67 +21,108 @@ title: "Docker"
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-  
+
 In this quickstart, we will download the Apache Druid image from [Docker 
Hub](https://hub.docker.com/r/apache/druid) and set it up on a single machine 
using [Docker](https://www.docker.com/get-started) and [Docker 
Compose](https://docs.docker.com/compose/). The cluster will be ready to load 
data after completing this initial setup.
 
-Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with Docker is recommended.
+Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with 
[Docker](https://www.docker.com/get-started) is recommended.
+
+This tutorial assumes you will download the required files from GitHub. The 
files are also available in a Druid installation and in the Druid sources.
 
 ## Prerequisites
 
-* Docker
+* [Docker](https://www.docker.com/get-started)
 
 ## Getting started
 
-The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which can pull an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments.
+Create a directory to hold the Druid Docker files.
+
+The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which pulls an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 this file to the directory created above.
 
 ### Compose file
 
-The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store. 
+The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store.
 
-It will also create a named volumes `druid_shared`, which is mounted as 
`opt/shared` in container, as deep storage to keep and share segments and task 
logs among Druid services.
+It will also create a named volume `druid_shared` as deep storage to keep and 
share segments and task logs among Druid services. The volume is mounted as 
`opt/shared` in the container.
 
-The Druid containers are configured via an [environment 
file](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment).
+### Environment file
+
+The Druid `docker-compose.yml` example utilizes an [environment 
file](https://docs.docker.com/compose/environment-variables/#the-env_file-configuration-option)
 to specify the complete Druid configuration, including the environment 
variables listed below. This file is named `environment` by default, and must 
be in the same directory as the `docker-compose.yml` file. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/environment)
 the example `environment` file to the directory created above. The options in 
this file work well for trying Druid and for using the tutorial.
+
+The single-file approach is inadequate for a production system. Instead we 
suggest using either `DRUID_COMMON_CONFIG` and `DRUID_CONFIG_${service}` or 
specially tailored, service-specific environment files.
 
 ### Configuration
 
-Configuration of the Druid Docker container is done via environment variables, 
which may additionally specify paths to [the standard Druid configuration 
files](../configuration/index.md)
+Configuration of the Druid Docker container is done via environment variables 
set within the container. Docker Compose passes the values from the 
`environment file` into the container. The variables may additionally specify 
paths to [the standard Druid configuration files](../configuration/index.md) 
which must be available within the container.
+
+The default values are fine for the Quickstart. Production systems will want 
to modify the defaults.
 
-Special environment variables:
+Basic configuration:
+
+* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size. Default is 6 
GB.
+* `DRUID_XMX` -- set Java `Xmx`, the maximum heap size. Default is 1 GB.
+
+Production configuration:
 
-* `JAVA_OPTS` -- set java options
-* `DRUID_LOG4J` -- set the entire `log4j.xml` verbatim
-* `DRUID_LOG_LEVEL` -- override the default log level in default log4j
-* `DRUID_XMX` -- set Java `Xmx`
-* `DRUID_XMS` -- set Java `Xms`
-* `DRUID_MAXNEWSIZE` -- set Java max new size
-* `DRUID_NEWSIZE` -- set Java new size
-* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size
 * `DRUID_CONFIG_COMMON` -- full path to a file for druid 'common' properties
 * `DRUID_CONFIG_${service}` -- full path to a file for druid 'service' 
properties
+* `JAVA_OPTS` -- set Java options
+
+Logging configuration:
+
+* `DRUID_LOG4J` -- set the entire [`log4j.xml` configuration 
file](https://logging.apache.org/log4j/2.x/manual/configuration.html#XML)  
verbatim. 
([Example](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment#L52))
+* `DRUID_LOG_LEVEL` -- override the default [Log4j log 
level](https://en.wikipedia.org/wiki/Log4j#Log4j_log_levels)
+
+Advanced memory configuration:
+
+* `DRUID_XMS` -- set Java 
[`Xms`](https://docs.oracle.com/cd/E19900-01/819-4742/abeik/index.html), the 
initial heap size. Default is 1 GB.
+* `DRUID_MAXNEWSIZE` -- set [Java max new 
size](https://docs.oracle.com/cd/E19900-01/819-4742/abeik/index.html)
+* `DRUID_NEWSIZE` -- set [Java new 
size](https://docs.oracle.com/cd/E19900-01/819-4742/abeik/index.html)
 
-In addition to the special environment variables, the script which launches 
Druid in the container will also attempt to use any environment variable 
starting with the `druid_` prefix as a command-line configuration. For example, 
an environment variable
- 
-```druid_metadata_storage_type=postgresql```
- 
-would be translated into 
+In addition to the special environment variables, the script which launches 
Druid in the container will use any environment variable starting with the 
`druid_` prefix as command-line configuration. For example, an environment 
variable
 
-```-Ddruid.metadata.storage.type=postgresql```
- 
-for the Druid process in the container.
+`druid_metadata_storage_type=postgresql`
+
+is translated into the following option in the Java launch command for the 
Druid process in the container:
+
+`-Ddruid.metadata.storage.type=postgresql`
+
+Note that Druid uses port 8888 for the console. This port is also used by 
Jupyter and other tools. To avoid conflicts, you can change the port in the 
[ports](https://github.com/apache/druid/blob/0.21.1/distribution/docker/docker-compose.yml#L125)
 section of the `docker-compose.yml` file. Example to expose the Console on 
port 9999 of the host:

Review comment:
       Should the version `0.21.1`  be replaced with the `{{DRUIDVERSION}}` in 
these github links? 
   
   ```suggestion
   Note that Druid uses port 8888 for the console. This port is also used by 
Jupyter and other tools. To avoid conflicts, you can change the port in the 
[ports](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml#L125)
 section of the `docker-compose.yml` file. Example to expose the Console on 
port 9999 of the host:
   ```

##########
File path: docs/tutorials/docker.md
##########
@@ -21,67 +21,108 @@ title: "Docker"
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-  
+
 In this quickstart, we will download the Apache Druid image from [Docker 
Hub](https://hub.docker.com/r/apache/druid) and set it up on a single machine 
using [Docker](https://www.docker.com/get-started) and [Docker 
Compose](https://docs.docker.com/compose/). The cluster will be ready to load 
data after completing this initial setup.
 
-Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with Docker is recommended.
+Before beginning the quickstart, it is helpful to read the [general Druid 
overview](../design/index.md) and the [ingestion 
overview](../ingestion/index.md), as the tutorials will refer to concepts 
discussed on those pages. Additionally, familiarity with 
[Docker](https://www.docker.com/get-started) is recommended.
+
+This tutorial assumes you will download the required files from GitHub. The 
files are also available in a Druid installation and in the Druid sources.
 
 ## Prerequisites
 
-* Docker
+* [Docker](https://www.docker.com/get-started)
 
 ## Getting started
 
-The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which can pull an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments.
+Create a directory to hold the Druid Docker files.
+
+The Druid source code contains [an example 
`docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 which pulls an image from Docker Hub and is suited to be used as an example 
environment and to experiment with Docker based Druid configuration and 
deployments. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml)
 this file to the directory created above.
 
 ### Compose file
 
-The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store. 
+The example `docker-compose.yml` will create a container for each Druid 
service, as well as ZooKeeper and a PostgreSQL container as the metadata store.
 
-It will also create a named volumes `druid_shared`, which is mounted as 
`opt/shared` in container, as deep storage to keep and share segments and task 
logs among Druid services.
+It will also create a named volume `druid_shared` as deep storage to keep and 
share segments and task logs among Druid services. The volume is mounted as 
`opt/shared` in the container.
 
-The Druid containers are configured via an [environment 
file](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment).
+### Environment file
+
+The Druid `docker-compose.yml` example utilizes an [environment 
file](https://docs.docker.com/compose/environment-variables/#the-env_file-configuration-option)
 to specify the complete Druid configuration, including the environment 
variables listed below. This file is named `environment` by default, and must 
be in the same directory as the `docker-compose.yml` file. 
[Download](https://raw.githubusercontent.com/apache/druid/{{DRUIDVERSION}}/distribution/docker/environment)
 the example `environment` file to the directory created above. The options in 
this file work well for trying Druid and for using the tutorial.
+
+The single-file approach is inadequate for a production system. Instead we 
suggest using either `DRUID_COMMON_CONFIG` and `DRUID_CONFIG_${service}` or 
specially tailored, service-specific environment files.
 
 ### Configuration
 
-Configuration of the Druid Docker container is done via environment variables, 
which may additionally specify paths to [the standard Druid configuration 
files](../configuration/index.md)
+Configuration of the Druid Docker container is done via environment variables 
set within the container. Docker Compose passes the values from the 
`environment file` into the container. The variables may additionally specify 
paths to [the standard Druid configuration files](../configuration/index.md) 
which must be available within the container.
+
+The default values are fine for the Quickstart. Production systems will want 
to modify the defaults.
 
-Special environment variables:
+Basic configuration:
+
+* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size. Default is 6 
GB.
+* `DRUID_XMX` -- set Java `Xmx`, the maximum heap size. Default is 1 GB.
+
+Production configuration:
 
-* `JAVA_OPTS` -- set java options
-* `DRUID_LOG4J` -- set the entire `log4j.xml` verbatim
-* `DRUID_LOG_LEVEL` -- override the default log level in default log4j
-* `DRUID_XMX` -- set Java `Xmx`
-* `DRUID_XMS` -- set Java `Xms`
-* `DRUID_MAXNEWSIZE` -- set Java max new size
-* `DRUID_NEWSIZE` -- set Java new size
-* `DRUID_MAXDIRECTMEMORYSIZE` -- set Java max direct memory size
 * `DRUID_CONFIG_COMMON` -- full path to a file for druid 'common' properties
 * `DRUID_CONFIG_${service}` -- full path to a file for druid 'service' 
properties

Review comment:
       ```suggestion
   * `DRUID_CONFIG_${service}` -- full path to a file for Druid service 
properties
   ```




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