CycleCloud ZooKeeper Sample Cluster

The CycleCloud ZooKeeper sample demonstrates configuring and launching a basic Apache ZooKeeper ( https://zookeeper.apache.org/ ) cluster from the CycleCloud GUI.

Pre-Requisites

This sample requires the following:

1. CycleCloud must be installed and running.
   1. If this is not the case, see the CycleCloud QuickStart Guide for assistance.
2. The CycleCloud CLI must be installed and configured for use.
3. You must have access to log in to CycleCloud.
4. You must have access to upload data and launch instances in your chosen Cloud Provider account.
5. You must have access to a configured CycleCloud "Locker" for Project Storage (Cluster-Init and Chef).
6. Optional: To use the cyclecloud project upload <locker> command, you must have a Pogo configuration file set up with write-access to your locker.
   1. You may use your preferred tool to interact with your storage "Locker" instead.

NOTE:

The instructions in this guide assume the use of Amazon Web Services for the Cloud Provider account.

Usage

A. Configuring the Project

The first step is to configure the project for use with your storage locker:

1. Open a terminal session with the CycleCloud CLI enabled.

2. Switch to the ZooKeeper sample directory.

3. Run cyclecloud project add_target my_locker (assuming the locker is named "my_locker"). The locker name will generally be the same as the cloud provider you created when configuring CycleCloud. The expected output looks like this::

   $ cyclecloud project add_target my_locker
   Name: zookeeper
   Version: 1.0.0
   Targets:
      my_locker: {'default': 'true', 'is_locker': 'true'}
   

   NOTE: You may call add_target as many times as needed to add additional target lockers.

B. Deploying the Project

To upload the project (including any local changes) to your target locker, run the cyclecloud project upload command from the project directory. The expected output looks like this::

$ cyclecloud project upload
Sync completed!

IMPORTANT

For the upload to succeed, you must have a valid Pogo configuration for your target Locker.

C. Importing the Cluster Template

To import the cluster:

1. Open a terminal session with the CycleCloud CLI enabled.

2. Switch to the ZooKeeper sample directory.

3. Run cyclecloud import_template zookeeper -f ./templates/zookeeper.txt. The expected output looks like this::

   $ cyclecloud import_template zookeeper -f ./zookeeper.txt
   Importing template zookeeper....
   ----------------------
   ZooKeeper : *template*
   ----------------------
   Keypair: $keypair
   Cluster nodes:
       proxy: off
   Total nodes: 1
   

D. Creating a ZooKeeper Cluster

1. Log in to your CycleCloud from your browser.
2. Click the "Clusters" to navigate to the CycleCloud "Clusters" page, if you are not already there.
3. Click the "+" button in the "Clusters" frame to create a new cluster.
4. In the cluster creation page, click on the ZooKeeper cluster icon.
5. At a minimum, select the Cloud Provider Credentials to use and enter a Name for the cluster.
6. Click the "Start" button.

E. Starting and Stopping the ZooKeeper Cluster

1. Select the newly created ZooKeeper cluster from the Clusters frame on the CycleCloud "Clusters" page
2. To start the cluster, click the Start link in the cluster status frame.
3. Later, to stop a started cluster, click the Terminate link in the cluster status frame.

F. Monitoring ZooKeeper

1. Use the ZooKeeper 4-letter words (see: https://zookeeper.apache.org/doc/trunk/zookeeperAdmin.html#The+Four+Letter+Words ):
   1. Install Netcat: yum install -y nc
   2. Send 4-letter words via echo: echo mntr | nc localhost 2181
2. Download zkTop to one of the ensemble members:
   1. Download the zip from https://github.com/phunt/zktop
   2. Extract the zip onto an ensemble member
   3. Run: python zkTop.py --config /etc/zookeeper/zoo.cfg
3. You can also use JMX for detailed monitoring. See: https://zookeeper.apache.org/doc/trunk/zookeeperJMX.html