:sectnums:
= Batch Job on Cloud Foundry

In this demonstration, you will learn how to orchestrate short-lived data processing application (_eg: Spring Batch Jobs_) using http://cloud.spring.io/spring-cloud-task/[Spring Cloud Task] and http://cloud.spring.io/spring-cloud-dataflow/[Spring Cloud Data Flow] on Cloud Foundry.

== Using Cloud Foundry Server

=== Prerequisites

In order to get started, make sure that you have the following components:

* Local https://pivotal.io/pcf-dev[PCFDev] instance 
* Local install of https://github.com/cloudfoundry/v3-cli-plugin[V3-CF-CLI] plugin
* Local build of https://github.com/spring-cloud/spring-cloud-dataflow[Spring Cloud Data Flow]
* Local build of Spring Cloud Data Flow's https://github.com/spring-cloud/spring-cloud-dataflow-server-cloudfoundry[Cloud Foundry Server]
* Running instance of mysql in PCFDev

NOTE: PCF 1.7.12 or greater is required to run Tasks on Spring Cloud Data Flow. As of this writing, PCFDev and PWS supports builds upon this version.

=== Running the Sample in Cloud Foundry

. Verify that CF instance is reachable
+

```
→ cf api
API endpoint: https://api.local.pcfdev.io (API version: 2.54.0)

$ cf apps
Getting apps in org user-dataflow / space development as user...
OK

No apps found
```
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. Follow the http://docs.spring.io/spring-cloud-dataflow-server-cloudfoundry/docs/current-SNAPSHOT/reference/htmlsingle/#getting-started[getting-started] instructions to deploy Spring Cloud Data Flow's Cloud Foundry Server

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NOTE: For this sample, all you need is the `mysql` service and in PCFDev, the `mysql` service comes with a different plan. From CF CLI, create the service by: `cf create-service p-mysql 512mb mysql` and bind this service to `dataflow-server` by: `cf bind-service dataflow-server mysql`.
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NOTE: All the apps deployed to PCFDev start with low memory by default. It is recommended to change it to at least 512MB for `dataflow-server`. Change the memory by: `cf set-env dataflow-server SPRING_CLOUD_DEPLOYER_CLOUDFOUNDRY_MEMORY 512`. Likewise, we would have to skip SSL validation by: `cf set-env dataflow-server SPRING_CLOUD_DEPLOYER_CLOUDFOUNDRY_SKIP_SSL_VALIDATION true`.

. Once you complete the instructions, you'll be able to list the newly deployed `dataflow-server`

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```
$ cf apps
Getting apps in org user-dataflow / space development as user...
OK

name             requested state   instances   memory   disk   urls
dataflow-server  started           1/1         512M     512M   dataflow-server.local.pcfdev.io
```
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NOTE: The `ORG`, `SPACE` and `USER` could vary depending on your Cloud Foundry environment in use.

. Tasks in Spring Cloud Data Flow requires an RDBMS to host "task repository" (see http://docs.spring.io/spring-cloud-dataflow/docs/1.0.0.RELEASE/reference/htmlsingle/#spring-cloud-dataflow-task-repository[here] for more details), so let's bind `mysql` service and restage the `dataflow-server`

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```
$ cf set-env dataflow-server SPRING_CLOUD_DEPLOYER_CLOUDFOUNDRY_TASK_SERVICES mysql
$ cf restage dataflow-server
```
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NOTE: We only need `mysql` service for this sample.

. Notice that `dataflow-server` application is started and ready for interaction via `http://dataflow-server.local.pcfdev.io` endpoint

. Connect to Spring Cloud Data Flow's `shell`. 
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```
$ cd <PATH/TO/SPRING-CLOUD-DATAFLOW>
$ java -jar spring-cloud-dataflow-shell/target/spring-cloud-dataflow-shell-<VERSION>.jar

  ____                              ____ _                __
 / ___| _ __  _ __(_)_ __   __ _   / ___| | ___  _   _  __| |
 \___ \| '_ \| '__| | '_ \ / _` | | |   | |/ _ \| | | |/ _` |
  ___) | |_) | |  | | | | | (_| | | |___| | (_) | |_| | (_| |
 |____/| .__/|_|  |_|_| |_|\__, |  \____|_|\___/ \__,_|\__,_|
  ____ |_|    _          __|___/                 __________
 |  _ \  __ _| |_ __ _  |  ___| | _____      __  \ \ \ \ \ \
 | | | |/ _` | __/ _` | | |_  | |/ _ \ \ /\ / /   \ \ \ \ \ \
 | |_| | (_| | || (_| | |  _| | | (_) \ V  V /    / / / / / /
 |____/ \__,_|\__\__,_| |_|   |_|\___/ \_/\_/    /_/_/_/_/_/

<VERSION>

Welcome to the Spring Cloud Data Flow shell. For assistance hit TAB or type "help".
server-unknown:>
```
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. Connect `shell` with the `server` running at `http://dataflow-server.local.pcfdev.io`
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```
server-unknown:>dataflow config server http://dataflow-server.local.pcfdev.io
Successfully targeted http://dataflow-server.local.pcfdev.io
dataflow:>version
<VERSION>
```
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. Verify there's no Task applications running on PCFDev using `v3-cf-cli`

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```
→ cf v3-apps
No v3 apps found.
```
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. Let's build and register the batch-job https://github.com/spring-cloud/spring-cloud-task/tree/master/spring-cloud-task-samples/batch-job[example] from Spring Cloud Task samples. For convenience, the final https://github.com/spring-cloud/spring-cloud-dataflow-samples/raw/master/tasks/simple-batch-job/batch-job-1.0.0.BUILD-SNAPSHOT.jar[uber-jar artifact] is provided with this sample

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```
dataflow:>app register --type task --name simple_batch_job --uri https://github.com/spring-cloud/spring-cloud-dataflow-samples/raw/master/tasks/simple-batch-job/batch-job-1.0.0.BUILD-SNAPSHOT.jar
```
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. Create the task with `simple-batch-job` application

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```
dataflow:>task create foo --definition "simple_batch_job"
```
NOTE: Unlike Streams, the Task definitions don't require explicit deployment. They can be launched on-demand, scheduled, or triggered by streams. 

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. Verify there's *still* no Task applications running on PCFDev - they are listed only after the initial launch/staging attempt on PCF

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```
→ cf v3-apps
No v3 apps found.
```
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. Let's launch `foo`

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```
dataflow:>task launch foo 
```
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. Verify the execution of `foo` by tailing the logs

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```
→ cf v3-logs foo 
Tailing logs for app foo...

2016-08-14T18:48:54.22-0700 [APP/TASK/foo/0]OUT Creating container
2016-08-14T18:48:55.47-0700 [APP/TASK/foo/0]OUT

2016-08-14T18:49:06.59-0700 [APP/TASK/foo/0]OUT 2016-08-15 01:49:06.598  INFO 14 --- [           main] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=job1]] launched with the following parameters: [{}]

...
...

2016-08-14T18:49:06.78-0700 [APP/TASK/foo/0]OUT 2016-08-15 01:49:06.785  INFO 14 --- [           main] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=job1]] completed with the following parameters: [{}] and the following status: [COMPLETED]

...
...

2016-08-14T18:49:07.36-0700 [APP/TASK/foo/0]OUT 2016-08-15 01:49:07.363  INFO 14 --- [           main] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=job2]] launched with the following parameters: [{}]

...
...

2016-08-14T18:49:07.53-0700 [APP/TASK/foo/0]OUT 2016-08-15 01:49:07.536  INFO 14 --- [           main] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=job2]] completed with the following parameters: [{}] and the following status: [COMPLETED]

...
...

2016-08-14T18:49:07.71-0700 [APP/TASK/foo/0]OUT Exit status 0
2016-08-14T18:49:07.78-0700 [APP/TASK/foo/0]OUT Destroying container
2016-08-14T18:49:08.47-0700 [APP/TASK/foo/0]OUT Successfully destroyed container

```
NOTE: Verify `job1` and `job2` operations embeddded in `simple-batch-job` application are launched independently and they returned with the status `COMPLETED`.

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NOTE: Unlike LRPs in Cloud Foundry, tasks are short-lived, so the logs aren't always available. They are generated only when the Task application runs; at the end of Task operation, the container that ran the Task application is destroyed to free-up resources.
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. List Tasks in Cloud Foundry

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```
→ cf v3-apps
name       total_desired_instances
foo        0
```
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. Verify Task execution details

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```
dataflow:>task execution list
╔══════════════════════════╤══╤════════════════════════════╤════════════════════════════╤═════════╗
║        Task Name         │ID│         Start Time         │          End Time          │Exit Code║
╠══════════════════════════╪══╪════════════════════════════╪════════════════════════════╪═════════╣
║Demo Batch Job Task:cloud:│1 │Sun Aug 14 18:49:05 PDT 2016│Sun Aug 14 18:49:07 PDT 2016│0        ║
╚══════════════════════════╧══╧════════════════════════════╧════════════════════════════╧═════════╝
```

. Verify Job execution details

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```
dataflow:>job execution list
╔═══╤═══════╤═════════╤════════════════════════════╤═════════════════════╤══════════════════╗
║ID │Task ID│Job Name │         Start Time         │Step Execution Count │Definition Status ║
╠═══╪═══════╪═════════╪════════════════════════════╪═════════════════════╪══════════════════╣
║2  │1      │job2     │Sun Aug 14 18:49:07 PDT 2016│1                    │Destroyed         ║
║1  │1      │job1     │Sun Aug 14 18:49:06 PDT 2016│1                    │Destroyed         ║
╚═══╧═══════╧═════════╧════════════════════════════╧═════════════════════╧══════════════════╝
```
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== Summary 

In this sample, you have learned:

* How to register and orchestrate Spring Batch jobs in Spring Cloud Data Flow
* How to use `v3-cf-cli` in the context of Task applications orchestrated by Spring Cloud Data Flow
* How to verify task executions and task repository 
