Ansible Role: ZooKeeper

This is an Ansible role for installing and setting up Apache ZooKeeper.

Role Variables

Here are the available settings (with default values) you can change in the defaults/main.yml file:

• zookeeper_version: 3.6.2
  Version of the ZooKeeper application.

• zookeeper_dir: /opt/zookeeper
  Directory for storing application files.

• zookeeper_data_dir: /var/zookeeper
  Directory for server data.

• zookeeper_conf_dir: /etc/zookeeper
  Directory for server configuration.

• zookeeper_log_dir: /var/log/zookeeper
  Directory for server logs.

• zookeeper_log_file: zookeeper.log
  Name of the log file.

• zookeeper_log_level: INFO
  Level of logging.

• zookeeper_log_max_file_size: 265MB
  Maximum size of the log file before it rotates.

• zookeeper_log_max_backup_index: 20
  Maximum number of log files to keep.

• zookeeper_client_port: 2181
  Port for client connections.

• zookeeper_init_limit: 5

• zookeeper_sync_limit: 2

• zookeeper_tick_time: 2000
  For more information, check the official ZooKeeper documentation.

• zookeeper_members: "{{ groups['all'] | map('extract', hostvars, 'ansible_default_ipv4') | map(attribute='address') | list }}"
  Members of the ZooKeeper cluster. You can use a list of hostnames, fully qualified domain names (FQDN), or IP addresses.

• zookeeper_member_id: "{{ ansible_default_ipv4.address }}"
  ID for the current cluster member (its position in the zookeeper_members list).

• zookeeper_server_username: foo

• zookeeper_server_password: foz
  Credentials for the cluster member's communication.

• zookeeper_clients:

  • username: bar
    password: baz
    Credentials for client access.

• zookeeper_jmx_host: 127.0.0.1
  JMX will be accessible on this hostname/IP.

• zookeeper_jmx_port: 9181
  Port for the JMX remote agent.

• zookeeper_jmx_rmi_port: 9182
  Port for the RMI connector.

• zookeeper_jmx_username: foz

• zookeeper_jmx_password: baz
  Credentials for JMX access.

• zookeeper_jmx_role: readonly
  Role for the JMX user.

• zookeeper_4lw_commands_whitelist: srvr,stat,mntr
  List of allowed ZooKeeper 4lw commands.

• zookeeper_global_outstanding_limit: 1000
  Reference: [ZooKeeper Administrator's Guide].

• zookeeper_prealloc_size: 64M
  Reference: [ZooKeeper Administrator's Guide].

• zookeeper_snap_count: 100000
  Reference: [ZooKeeper Administrator's Guide].

• zookeeper_max_client_cnxns: 10
  Reference: [ZooKeeper Administrator's Guide].

• zookeeper_min_session_timeout: "{{ 2 * zookeeper_tick_time }}"
  Reference: [ZooKeeper Administrator's Guide].

• zookeeper_max_session_timeout: "{{ 20 * zookeeper_tick_time }}"
  Reference: [ZooKeeper Administrator's Guide].

• zookeeper_autopurge_snapretain_count: 10
  Reference: [Clickhouse Usage Recommendations for ZooKeeper].

• zookeeper_purge_interval: 1
  Reference: [Clickhouse Usage Recommendations for ZooKeeper].

• zookeeper_fsync_warning_threshold_ms: 1000
  Reference: [ZooKeeper Administrator's Guide].

• zookeeper_heap_size: 1024
  The JVM heap size in MB.

Dependencies

Requires nl2go.openjdk.

Example Playbook

- hosts: all
  roles:
    - nl2go.zookeeper

Development

Use docker-molecule as per the instructions to run Molecule, or you can install Molecule locally (note: this may lead to version conflicts).

Set your Hetzner Cloud token:

export HCLOUD_TOKEN=123abc456efg

To run tests, use:

molecule test --all

Maintainers

• build-failure

License

Please refer to the LICENSE.md file for details.

Author Information

This role was created in 2020 by Newsletter2Go GmbH.

For more information, check the ZooKeeper Administrator's Guide and Clickhouse Usage Recommendations for Zoookeper.