-`rabbitmq_exchange_type` – The type of RabbitMQ exchange: `direct`, `fanout`, `topic`, `headers`, `consistent_hash`. Default: `fanout`.
-`rabbitmq_routing_key_list` – A comma-separated list of routing keys.
-`rabbitmq_row_delimiter` – Delimiter character, which ends the message.
-`rabbitmq_schema` – Parameter that must be used if the format requires a schema definition. For example, [Cap’n Proto](https://capnproto.org/) requires the path to the schema file and the name of the root `schema.capnp:Message` object.
-`rabbitmq_num_consumers` – The number of consumers per table. Default: `1`. Specify more consumers if the throughput of one consumer is insufficient.
-`rabbitmq_num_queues` – The number of queues per consumer. Default: `1`. Specify more queues if the capacity of one queue per consumer is insufficient.
-`rabbitmq_transactional_channel` – Wrap insert queries in transactions. Default: `0`.
-`rabbitmq_queue_base` - Specify a base name for queues that will be declared.
-`rabbitmq_queue_base` - Specify a base name for queues that will be declared. By default, queues are declared unique to tables based on db and table names.
-`rabbitmq_deadletter_exchange` - Specify name for a [dead letter exchange](https://www.rabbitmq.com/dlx.html). You can create another table with this exchange name and collect messages in cases when they are republished to dead letter exchange. By default dead letter exchange is not specified.
-`persistent` - If set to 1 (true), in insert query delivery mode will be set to 2 (marks messages as 'persistent'). Default: `0`.
-`rabbitmq_skip_broken_messages` – RabbitMQ message parser tolerance to schema-incompatible messages per block. Default: `0`. If `rabbitmq_skip_broken_messages = N` then the engine skips *N* RabbitMQ messages that cannot be parsed (a message equals a row of data).
-`rabbitmq_max_block_size`
-`rabbitmq_flush_interval_ms`
Required configuration:
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@@ -96,16 +105,18 @@ Exchange type options:
-`consistent-hash` - Data is evenly distributed between all bound tables (where exchange name is the same). Note that this exchange type must be enabled with RabbitMQ plugin: `rabbitmq-plugins enable rabbitmq_consistent_hash_exchange`.
Setting `rabbitmq_queue_base` may be used for the following cases:
- to be able to restore reading from certain durable queues when not all messages were successfully consumed. Note: it makes sence only if messages are sent with delivery mode 2 - marked 'persistent', durable. To be able to resume consumption from one specific queue - set its name in `rabbitmq_queue_base` setting and do not specify `rabbitmq_num_consumers` and `rabbitmq_num_queues` (defaults to 1). To be able to resume consumption from all queues, which were declared for a specific table - just specify the same settings: `rabbitmq_queue_base`, `rabbitmq_num_consumers`, `rabbitmq_num_queues`. By default, queue names will be unique to tables.
- to let different tables share queues, so that multiple consumers could be registered for the same queues, which makes a better performance. If using `rabbitmq_num_consumers` and/or `rabbitmq_num_queues` settings, the exact match of queues is achieved in case these parameters are the same.
- to be able to restore reading from certain durable queues when not all messages were successfully consumed. To be able to resume consumption from one specific queue - set its name in `rabbitmq_queue_base` setting and do not specify `rabbitmq_num_consumers` and `rabbitmq_num_queues` (defaults to 1). To be able to resume consumption from all queues, which were declared for a specific table - just specify the same settings: `rabbitmq_queue_base`, `rabbitmq_num_consumers`, `rabbitmq_num_queues`. By default, queue names will be unique to tables. Note: it makes sence only if messages are sent with delivery mode 2 - marked 'persistent', durable.
- to reuse queues as they are declared durable and not auto-deleted.
- to let different tables share queues, so that multiple consumers could be registered for the same queues, which makes better performance. If using `rabbitmq_num_consumers` and/or `rabbitmq_num_queues` settings, the exact match of queues is achieved in case these parameters are the same.
To improve performance, received messages are grouped into blocks the size of [max\_insert\_block\_size](../../../operations/server-configuration-parameters/settings.md#settings-max_insert_block_size). If the block wasn’t formed within [stream\_flush\_interval\_ms](../../../operations/server-configuration-parameters/settings.md) milliseconds, the data will be flushed to the table regardless of the completeness of the block.
If `rabbitmq_num_consumers` and/or `rabbitmq_num_queues` settings are specified along with `rabbitmq_exchange_type`, then:
-`rabbitmq-consistent-hash-exchange` plugin must be enabled.
-`message_id` property of the published messages must be specified (unique for each message/batch).
For insert query there is message metadata, which is added for each published message: messageID and republished flag - can be accessed via message headers.
For insert query there is message metadata, which is added for each published message: `messageID` and `republished` flag (true, if published more than once) - can be accessed via message headers.
Do not use the same table for inserts and materialized views.
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@@ -134,6 +145,7 @@ Example:
## Virtual Columns {#virtual-columns}
-`_exchange_name` - RabbitMQ exchange name.
-`_consumer_tag` - ConsumerTag of the consumer that received the message.
-`_delivery_tag` - DeliveryTag if the message. Scoped per consumer.
-`_channel_id` - ChannelID, on which consumer, who received the message, was declared.
-`_delivery_tag` - DeliveryTag of the received message. Scoped per channel.
-`_redelivered` - Redelivered flag of the message.
-`_message_id` - messageID of the received message; non-empty if was set, when message was published.
