Wednesday

A demo of the Hazelcast PCF Tile, written on a Wednesday

Do not share, the UI is laughable and there's a license key in the JSON files.

To use on a full PCF environment, with the Tile ready uploaded

1 Login

cf login -a api.system.pcf.hazelcast.com

Refer to the wiki for credentials. I use admin login which is probably excessive.

• Validate

Try cf marketplace, there should be a hazelcast entry for the Tile. Against this tile should be some pre-defined service plans, where a plan defines the virtual machine strength.

2 Create a Service

cf create-service hazelcast t2.micro cfsummit -c ..../before.json

A Service in CloudFoundry terms is a back-end application, available for front-end applications to bind to.

The back-end application here that the Tile holds is a Hazelcast IMDG server. Specifically, hazelcast-enterprise.jar and nothing else. No user code, no other Hazelcast jars.

What the create-service command is doing here is selecting the hazelcast Tile, the t2.micro service plan (a small machine, something like 2 CPUs, 4Gb RAM) to form a service named cfsummit.

The file before.json is used to configure the service. Two important ones are instanceCount which dictates how many virtual machines to make, and mancenterAppName.

• Validate

Try cf s, the service should take a few minutes to build as it is spinning up AWS instances.

3 Mancenter

Once the service is started, the Mancenter will be available at http://mancenter-cfsummit.apps.pcf.hazelcast.com/mancenter.

Note the URL is the concatenation of mancenterAppName from the JSON configuration file, and the base domain for the PCF environment.

4 On a demo

What this means is three AWS instances are built for Hazelcast servers and one for the Mancenter.

Mancenter doesn't seem to be the last one to be built, though I don't know if you can rely on that. But it's worth trying that URL before the service creation has completed.

5 Application time

Deploy the application (Hazelcast Client).

On STS, using the Boot Dashboard panel. Probably a similar idea on Intellij.

This uses manifest.yml.

In this file, route: app.apps.pcf.hazelcast.com names the URL that the application will be available on. And services: cfsummit names the service(s) that the front-end application is bound to.

If successful, the application will be available as http://app.apps.pcf.hazelcast.com/

6 Scaling time

Now try

cf update-service cfsummit -c ..../after.json

This applies the new configuration file after.json to the running service.

What should happen is one at a time the servers are removed and restored. Not the Mancenter though, so you can keep this open and watch.

CF waits for the isClusterSafe() signal from a new VM before proceeding to the next one, and it's building AWS instances, so the whole thing will take a few minutes. So, get everyone in the room to use the application while this occurs.

Comparing before.json and after.json you'll see it's just the count of the number of servers that changes.

PCF (v1.10) isn't yet bright enough to spot that the optimisation available to just start an extra server. As far as it's is concerned the configuration has changed so each process needs restarted to pick up the new configuration.

To hack use on a PCF Dev environment, no Tile applicable

This is a hack. The Hazelcast server is external to the CloudFoundry environment. The application with the Hazelcast client is internal to the CloudFoundry environment. We create a dummy service with no implementation, so the application can bind to it and retrieve environment variables for the external application's address.

Really, we may as well provide that external address in the application's properties.

1 Create a Service

Use cups (Create User Provided Service) with the svc jar file in the project.

cf cups cfsummit -p "host,port"

When prompted, enter the external IP address of your localhost, then 5701. (eg. ifconfig | grep inet).

This makes a dummy service in PCF Dev, basically a way of passing binding parameters to the application.

• Validate

cf s

2 Start the service

From your localhost, java -jar svc/target/svc.jar

3 Deploy the application to PCF Dev

As before, varies if you do from IDE.

From command line

cf bind-service app cfsummit

cf restage cfsummit

NOTE Make sure the manifest.yml specifies the correct route. For PCF Dev it will be "app.local.pcfdev.io"

• Validate

cf a

and

cf env app

Then try http://app.local.pcfdev.io

To properly use on a PCF Dev environment, no Tile applicable

We need a service broker.

1 Deploy svc as an application

cf push -f svc/manifest-pcfdev.yml -p svc/target/svc.jar

Look in the start-up logs for the password generated. On the console, or cf logs svc --recent.

2017-06-13 13:24:27.809  INFO 7 --- [           main] b.a.s.AuthenticationManagerConfiguration : 
Using default security password: 19c17490-25c9-44ec-a4f2-60cd6c69a710

So the password is 19c17490-25c9-44ec-a4f2-60cd6c69a710, and this is for an account user.

• Validate

When this is done, cf a should list it.

2. Turn that application into a service broker

A service broker creates instances.

The command is

cf create-service-broker hazelcast-service-broker user 9b71a499-9665-453f-aff2-1cbdad373ca1 http://svc.local.pcfdev.io --space-scoped

With the password from the previous step.

• Validate

Try cf m to see if it is listed on the marketplace.

3 Create the service

Now try

cf create-service hazelcast plan1 cfsummit

to create a service using the hazelcast service, with the plan1 maching plan, and to call that service neil.

4 Deploy app as an application

Make sure the manifest.yml binds the app "app" to the service "neil".

cf push -f app/manifest-pcfdev.yml -p app/target/app.jar

5 Deploy app.js as an application

Make sure the manifest.yml binds the app "app.js" to the service "cfsummit".

cf push -f app.js/manifest.yml

To use without CF at all

Start the standalone service, java -Dserver.port=0 -jar svc/target/svc.jar

Start the application, java -jar app/target/app.jar

Start the Node.js client application, node app.js/app.js

Run http://localhost:8080

If the application gets nothing back from the Cloud Foundry lookup, it assumes localhost and 127.0.0.1.

Watch that the service has to be a web-app so we can deploy internally on PCF Dev, so make sure it doesn't pick 8080 or that will clash with the port the client tries to use.

Binding

When an application is bound to a service, this makes information available in an environment variable VCAP_SERVICES.

The "ui" on the application allows you to view this, and you can figure out how the client connects once you see this.

Note this is an environment variable, it doesn't change when we run update-service.

Use the Server IPs page on the application to see what was originally passed and what is currently in use. Do this during or after the update-service.

Application

The rest of the application shows two things, with a Stats and Person pages.

AtomicLong to count the number of hits to any page and the front page. Ideally you need to delete and redeploy the application while the service stays running to show distributed atomic counters.

Person and PersonRepository use Spring Data Hazelcast, so make everything Spring friendly. That means java.io.Serializable so no good for Node.js.