This repository contains a set of Ansible playbooks to easily create a simple BDR or UDR test set-up with two or more nodes running on localhost.

• Ansible ( http://www.ansible.com/ )
• psycopg2
• BDR-enabled PostgreSQL ( http://bdr-project.org/docs/stable/quickstart.html ) Note: bdr_demo_ansible will not build a BDR-enabled PostgreSQL; see http://bdr-project.org/docs/stable/installation-source.html for details on how to do this.

Create a file your_hostname.yml in the host_vars directory with the following variables (default values in parentheses):

• db_superuser (postgres)
• db_name (bdrdemo)
• bdr_bin: path to the BDR PostgreSQL bin/ directory
• base_data_dir: arbitrary directory for each BDR instance's data files
• base_log_dir (/tmp): directory for BDR/UDR PostgreSQL log files
• bdr_ports: list of ports for BDR PostgreSQL instances
• bdr_replica_src: port number of the initial BDR PostgreSQL instance, from which the other instances will replicate from (if in doubt, just use the first entry in bdr_ports).

Add your_hostname to the [bdr_hosts] section of hosts.ini

The file host_vars/sample_host.yml provides a useful template containing the parameters which will probably need to be configured.

MacPorts users: if Ansible complains about psycopg2 being missing, it is probably using the OS X native Python interpreter; set ansible_python_interpreter to point to the MacPorts version.

$ ansible-playbook -i hosts.ini bdr_init.yml

PLAY [all] ********************************************************************

TASK: [bdr_init | Create data directories] ************************************
changed: [nara] => (item=5597)
changed: [nara] => (item=5598)
changed: [nara] => (item=5599)

(...)

TASK: [bdr_init | Create BDR group] *******************************************
changed: [osaka]

TASK: [bdr_init | Add other nodes to group] ***********************************
skipping: [osaka] => (item=5597)
changed: [osaka] => (item=5598)
changed: [osaka] => (item=5599)

PLAY RECAP ********************************************************************
osaka                      : ok=15   changed=13   unreachable=0    failed=0


$ /path/to/pg_bdr/bin/psql -p 5597 bdrdemo
psql (9.4beta2)
Type "help" for help.

bdrdemo=# CREATE TABLE foo(id INT);
DEBUG:  attempting to acquire global DDL lock for (bdr (6056475237161047104,1,16384,))
DEBUG:  sent DDL lock request, waiting for confirmation
DEBUG:  global DDL lock acquired successfully by (bdr (6056475237161047104,1,16384,))
CREATE TABLE
Time: 16.755 ms
bdrdemo=# COMMENT ON TABLE foo IS 'Created on 5597';
COMMENT
Time: 28.503 ms
bdrdemo=# \q

$ /path/to/pg_bdr/bin/psql -p 5598 bdrdemo
psql (9.4beta2)
Type "help" for help.

bdrdemo=# \dt+
                      List of relations
 Schema | Name | Type  |  Owner  |  Size   |   Description
--------+------+-------+---------+---------+-----------------
 public | foo  | table | barwick | 0 bytes | Created on 5597
(1 row)

UDR setup is essentially the same as BDR setup.

Create a file your_hostname_udr.yml in the host_vars directory with the following variables (default values in parentheses):

• db_superuser (postgres)
• db_name (bdrdemo)
• bdr_bin: path to the UDR PostgreSQL bin/ directory
• base_data_dir: arbitrary directory for each BDR instance's data files
• base_log_dir (/tmp): directory for BDR/UDR PostgreSQL log files
• udr_ports: list of ports for UDR PostgreSQL instances
• udr_replica_src: port number of the initial UDR PostgreSQL instance, from which the other instances will replicate from (if in doubt, just use the first entry in udr_ports).

Currently only the servers will be set up (with appropriate configuration and extensions installed); the actual UDR configuration must be done manually

Following playbooks have been defined:

• bdr_init.yml

  Creates and configures BDR-enabled instances

• bdr_destroy.yml

  Halts existing BDR-enabled instances and removes the database directories

• bdr_start.yml

  Starts previously configured but not running BDR-enabled instances

• bdr_stop.yml

  Stops running BDR-enabled instances