Working with Policies

1. Creating Policy

Property	Description	Values
name	Name of the policy	`string`
pattern	Regular expression to match queue/exchange names	`string`
definition	JSON object defining the policy rules	`object`
priority	Priority of the policy (0-2147483647)	`integer`

Example: Creating a Policy

rabbitmq-policy set my-policy "^my-queue" '{"ha-mode":"all"}' 1

Note: Policies are applied to queues and exchanges matching the pattern.

2. Using Policy Pattern

Example: Define a policy for message TTL

{
  "name": "message-ttl-policy",
  "pattern": "^queue-.*",
  "definition": {
    "x-message-ttl": 30000
  },
  "priority": 1
}

Property	Description	Values
name	Unique identifier for the policy	`string`
pattern	Regex to match queue names	`string`
definition	Policy configuration as key-value pairs	`object`
priority	Higher values override lower ones	`integer`

Note: Policies apply to queues matching the pattern. They can override queue-level settings.

Warning: Policies are applied at queue creation time. Changing a policy does not affect existing queues.

3. Setting Policy Priority

Property	Values	Description
priority	`0-100`	Defines the priority of the policy. Higher numbers indicate higher priority.

Example: Setting Policy Priority

rabbitmq-policy set --priority 50 my-policy-name ^my-queue$ '{"max-length": 1000}'

4. Setting HA Policy

Property	Value	Description
pattern	`^my-queue.*`	Regular expression to match queue names
definition	`ha-mode`	Policy to apply to matching queues
priority	`0`	Priority of the policy (higher number = higher priority)

Example: Setting HA Policy

rabbitmq-policy set ha-all "^my-queue.*" '{"ha-mode":"all"}'

Note: The ha-mode can be set to all, exactly, or nodedown.

Warning: Ensure that the pattern matches the intended queues to avoid unintended policy application.

5. Setting Federation Policy

Property	Value	Description
federation.upstream	`string`	Name of the upstream federation exchange or queue
federation.upstream-exchange	`string`	Name of the upstream exchange to federate
federation.max-hops	`integer`	Maximum number of federation hops allowed (default: 1)
federation.reconnect-delay	`integer`	Seconds to wait before reconnecting (default: 5)

Example: Setting Federation Policy

rabbitmq-policy set federation-policy "federation-upstream" "^federated\." "{\"federation.upstream\":\"upstream-exchange\",\"federation.max-hops\":2}"

Note: Policies are applied to queues and exchanges matching a given pattern. Ensure the policy is set on the correct queue or exchange for federation to work.

6. Setting TTL Policy

Property	Value	Description
ttl	`3600000`	TTL in milliseconds (1 hour)
message-ttl	`3600000`	Time-to-live for messages in queue (1 hour)

Example: Set TTL Policy

rabbitmq-policy set ttl ^queue-name$ "{""message-ttl"":3600000}"

Note: The policy applies to all queues matching the pattern ^queue-name$.

7. Setting Max-Length Policy

Policy Name	Value	Description
max-length	`1000`	Maximum number of messages to keep in a queue before removing the oldest ones
max-length-bytes	`10485760`	Maximum total size of messages in bytes to keep in a queue before removing the oldest ones

Example: Setting max-length policy via CLI

rabbitmq-policy set --vhost / my-max-length-policy "^\w+queue$" "{\"max-length\": 1000}"

Example: Setting max-length-bytes policy via CLI

rabbitmq-policy set --vhost / my-max-length-bytes-policy "^\w+queue$" "{\"max-length-bytes\": 10485760}"

Note: The max-length policy applies to all queues matching the pattern, and will remove messages in FIFO order when the limit is reached.

8. Setting Queue Mode

Mode	Description	Configuration
classic	Standard queue type, stored in memory and disk	`"queue-mode": "classic"`
lazy	Messages are stored on disk and only loaded into memory when needed	`"queue-mode": "lazy"`
quorum	Highly available queue, replicated across cluster nodes	`"queue-mode": "quorum"`

Example: Setting Queue Mode via Policy

{
  "pattern": "^myqueue.*",
  "definition": {
    "queue-mode": "lazy"
  },
  "priority": 10
}

Note: Queue mode can be set at queue creation time or via a policy. Changing the mode of an existing queue requires deletion and recreation.

9. Combining Multiple Definitions

Example: Combining Policy Definitions

{
  "definition": "{\\"ha-mode\\":\\"all\\"}",
  "pattern": "^ha-.*$",
  "priority": 0,
  "apply-to": "all"
}

Property	Description	Values
definition	JSON string defining the policy	`{"ha-mode":"all"}`
pattern	Regex to match queue names	`^ha-.*$`
priority	Policy priority (0-2147483647)	`0`
apply-to	Which entities the policy applies to	`all`

Note: Policies are applied in order of priority, with higher numbers taking precedence.

Warning: Ensure pattern matches are specific enough to avoid unintended application.

10. Understanding Policy Application

Policy Property	Description	Values
pattern	Regular expression to match queue/exchange names	`^myqueue.*`
definition	JSON object defining the policy rules	`{"ha-mode":"all"}`
priority	Higher values take precedence over lower ones	`0`

Example: Applying a Policy to Queues

rabbitmq-policy set ha-all "^myqueue.*" '{"ha-mode":"all"}' --priority 1

Note: Policies are applied at the virtual host level and can target queues, exchanges, or both.

11. Listing Policies

Policy Name	Pattern	Definition	Priority
ha-all	`.*`	`{ "ha-mode": "all" }`	0
ttl-30days	`logs.*`	`{ "message-ttl": 2592000 }`	1

Example: List all policies

rabbitmqctl list_policies

Example: List policies with specific pattern

rabbitmqctl list_policies 'ha-.*'

12. Clearing Policy

Property	Description	Values
policy-name	Name of the policy to clear	`string`
vhost	Virtual host where the policy is defined	`string`

Example: Clearing a Policy

rabbitmqctl clear_policy -p /my_vhost my_policy_name

Note: The policy will be removed from the specified virtual host. If no virtual host is specified, the default vhost (/) will be used.