This is a set of Chef cookbooks to bring up Hadoop and Kafka clusters. In addition, there are a number of additional services provided with these cookbooks - such as DNS, metrics, and monitoring - see below for a partial list of services provided by these cookbooks.

Each Hadoop head node is Hadoop component specific. The roles are intended to be run so that they can be layered in a highly-available manner. E.g. multiple BCPC-Hadoop-Head-* machines will correctly build a MySQL, Zookeeper, HDFS JournalNode, etc. cluster and deploy the named component as well. Further, for components which support HA, the intention is one can simply add the role to multiple machines and the right thing will be done to support HA (except in the case of HDFS).

To setup HDFS HA, please follow the following model from your Bootstrap VM:

• Install the cluster once with a non-HA HDFS:
  • with a BCPC-Hadoop-Head-Namenode-NoHA role
  • with the following node variable [:bcpc][:hadoop][:hdfs][:HA] = false
  • ensure at least three machines are installed with BCPC-Hadoop-Head roles
  • ensure at least one machine is a datanode
  • run cluster-assign-roles.sh <Environment> Hadoop successfully
• Re-configure the cluster with an HA HDFS:
  • change the BCPC-Hadoop-Head-Namenode-NoHA machine's role to BCPC-Hadoop-Head-Namenode
  • set the following node variable [:bcpc][:hadoop][:hdfs][:HA] = true on all nodes (e.g. in the environment)
  • run cluster-assign-roles.sh <Environment> Hadoop successfully

These recipes are currently intended for building a BACH cluster on top of Ubuntu 12.04 servers using Chef 11. When setting this up in VMs, be sure to add a few dedicated disks (for HDFS data nodes) aside from boot volume. In addition, it's expected that you have three separate NICs per machine, with the following as defaults (and recommendations for VM settings):

• eth0 - management traffic (host-only NIC in VM)
• eth1 - reserved traffic (host-only NIC in VM)
• eth2 - compute traffic (host-only NIC in VM)

You should look at the various settings in cookbooks/bcpc/attributes/default.rb and tweak accordingly for your setup (by adding them to an environment file).

The provided scripts which sets up a Chef and Cobbler server via Vagrant permits imaging of the cluster via PXE.

Once the Chef server is set up, you can bootstrap any number of nodes to get them registered with the Chef server for your environment - see the next section for enrolling the nodes.

To build a new BACH cluster, you have to start with building head nodes first. (This assumes that you have already completed the bootstrap process and have a Chef server available.) Since the recipes will automatically generate all passwords and keys for this new cluster, the nodes must temporarily become admin's in the chef server, so that the recipes can write the generated info to a databag. The databag will be called configs and the databag item will be the same name as the environment (Test-Laptop in this example). You only need to leave the node as an admin for the first chef-client run. You can also manually create the databag & item (as per the example in data_bags/configs/Example.json) and manually upload it if you'd rather not bother with the whole admin thing for the first run.

To assign machines a role, one can update the cluster.txt file and ensure all necessary information is provided as per cluster-readme.txt.

Using the script tests/automated_install.sh, one can run through what is the expected "happy-path" install for a single machine running (by default) four VirtualBox VMs. This simple install supports only changing DNS, proxy and VM resource settings. (This is the basis of our automated build tests.)

In addition to the "happy-path" integration test using automated_install.sh there are ways to deploy on OpenStack or to bare-metal hosts. Lastly, for those using test-kitchen there are various test-kitchen suites one can run as well.

A view of the various full-cluster deployment types:

Once the nodes are configured and bootstrapped, BACH services will be accessible via the floating IP. (For the Test-Laptop environment, it is 10.0.100.5.)

For example, you can go to https://10.0.100.5:8888 for the Graphite web interface. To find the automatically-generated service credentials, look in the data bag for your environment.

ubuntu@bcpc-bootstrap:~$ knife data bag show configs Test-Laptop | grep mysql-root-password
mysql-root-password:       abcdefgh

For example, to check on HDFS:

ubuntu@bcpc-vm1:~$ HADOOP_USER_NAME=hdfs hdfs dfsadmin -report
Configured Capacity: 40781217792 (37.98 GB)
Present Capacity: 40114298221 (37.36 GB)
DFS Remaining: 39727463789 (37.00 GB)
DFS Used: 386834432 (368.91 MB)
DFS Used%: 0.96%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0

-------------------------------------------------
Live datanodes (1):

Name: 192.168.100.13:50010 (f-bcpc-vm3.bcpc.example.com)
Hostname: bcpc-vm3.bcpc.example.com
Decommission Status : Normal
Configured Capacity: 40781217792 (37.98 GB)
DFS Used: 386834432 (368.91 MB)
Non DFS Used: 666919571 (636.02 MB)
DFS Remaining: 39727463789 (37.00 GB)
DFS Used%: 0.95%
DFS Remaining%: 97.42%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 12
Last contact: Fri Aug 14 21:08:23 EDT 2015

BACH currently relies upon a number of open-source packages:

• Apache Bigtop
• Apache Hadoop
• Apache Spark
• Apache HBase
• Apache Hive
• Apache HTTP Server
• Apache Mahout
• Apache Oozie
• Apache Pig
• Apache Phoenix
• Apache Sqoop
• Apache Tez
• Apache Zookeeper
• Sentric Hannibal
• Twitter HDFS-DU
• Chef
• Cobbler
• Diamond
• Etherboot
• Graphite
• HAProxy
• Keepalived
• Percona XtraDB Cluster
• PowerDNS
• Ubuntu
• Vagrant - Verified with version 1.2.2
• VirtualBox - >= 4.3.x supported
• Zabbix

Thanks to all of these communities for producing this software!

To propose changes to Chef-BACH, please fork the GitHub repo and issue a pull request with your proposed change. We are endeavoring to follow the following standards:

Libraries:

• Chef Library Recommendations

All Chef Code:

• TomDoc

Static Code Analysis:

• Warnings not increased:
  • RuboCop
  • Foodcritic
    • Etsy rules
    • CustomInk rules
• Markup Verified With:
  • JSON: python -m json.tool <json files>
  • XML: xmllint --format <xml files>
  • ERB: erb -P -x -T '-' <erb file> | ruby -c

Otherwise generally follow bbatsov/ruby-style-guide

The GitHub workflow we follow is captured below: