Execution order

The order of action performed on the target host does NOT depend of the order in the description file. Action order is the following:

• Linux local groups are created
• Linux local users are created.
• Linux nodes folders are created.
• Files and trees with nodes as target are deployed
• Apache Ranger policies are applied
• hdfs_relay host is configured, if needed
• HDFS folders are created
• Files and trees with HDFS as target are deployed
• Elastic indices and templates are created
• hbase_relay host is configured if needed.
• HBase namespaces and table are created.
• HBase datasets are loaded
• hive_relay host is configured if needed.
• Hive databases and tables are created
• kafka_relay host is configured, if needed
• Kafka topics are created
• Services and Supervisor are deployed

Removal action order is the reverse.

Inside each action group, order is preserved. For example, with:

folders:
- { scope: en, path: /etc/broadapp, owner: root, group: root, mode: "0755" }
- { scope: en, path: /opt/broadapp, owner: root, group: root, mode: "0755" }

/etc/broadapp will be create before /opt/broadapp.

Same for variables. This is a single pass evaluation. So, obviously:

  app_version: "0.1.1"
  repository_server: "myserver.com"
  app_jar_url: "http://${repository_server}/repo/broadapp-${app_version}.jar"

Will be OK. While:

  app_jar_url: "http://${repository_server}/repo/broadapp-${app_version}.jar"
  app_version: "0.1.1"
  repository_server: "myserver.com"

Will fail, with a variable undefined error.

Plugin Priority

The order described above result from an ordering of the plugin execution.

To achieve this, internally, each plugin is granted with a priority for each action. And execution follow ascending order of priority.

Here are the values per plugin and action:

Plugin	grooming	deploy	remove	start	stop	status
header	1100	1100	1100	-	-	-
ansible_inventories	1200	1200	1200	-	-	-
inventory	1300 (3)	1300	1300	-	-	-
ansible	1400	(2)	(2)	-	-	-
users	2000	2000	7000	-	-	-
Nodes files & folders	3000	3000	4000	-	-	-
ranger	8000 (1)	3200	3700	-	-	-
hdfs files & folders	3500 (4)	3500	3500	-	-	-
Elastic	3700	3700	3200	-	-	-
hbase	4000	4000	3000	-	-	-
hive	4500	4500	2500	-	-	-
kafka	5000	5000	2000	-	-	-
Systemd	2500 (6)	6000	1800	5000	5000	5000
Supervisor	2510 (6)	7000	1600	6000	4000	5000
Storm	2520 (6)	7100 (5)	1500 (7)	6500	3500	5000
Yarn	2520 (6)	7050 (5)	1550 (7)	6400	3600	5000

NB: grooming is an internal action, performed on step 4 of the run

These priorities value are of interest if you insert some raw ansible playbooks or roles (Using ansible module) and want to control at which steps they will be executed.

(1): Ranger grooming must occurs after all ranger aware resources grooming

(2): Configured by the user in the deployment file

(3): Must be after ansible inventory, for host overriding

(4): Must be after files

(5): This plugin is involved in 'deploy' action only by files notification

(6): Must be before 'files', for notification handling

(7): Does not remove anything, but stop all running Storm topologies and/or Yarn services