Consumer Properties¶

AMPS-specific consumer properties control how the binder subscribes to AMPS topics and processes messages.

Prefix: spring.cloud.stream.amps.bindings.<channelName>.consumer

These properties can also be set as defaults for all bindings under spring.cloud.stream.amps.default.consumer.

Subscription Mode¶

`snapshot`¶

Type: boolean
Default: false

When true, the consumer performs a SOW query (snapshot only). The binder issues an AMPS SOW command, receives the current state-of-the-world, and does not continue subscribing for live updates.

Note

snapshot and sow are mutually exclusive. If both are true, snapshot takes precedence.

`sow`¶

Type: boolean
Default: false

When true, the consumer performs a SOW-and-Subscribe. The binder first receives the current state (SOW) and then continues to receive live updates as they arrive.

When both snapshot and sow are false (the default), the consumer uses a plain Subscribe command.

`snapshot`	`sow`	AMPS Command
`false`	`false`	`Subscribe`
`false`	`true`	`SOWAndSubscribe`
`true`	ignored	`SOW`

See SOW Queries for a detailed guide.

Content Filtering¶

`filter`¶

Type: String
Default: null

An AMPS content filter expression applied server-side to limit which messages the consumer receives. The filter syntax depends on the message type (e.g., JSON XPath for json message types).

spring.cloud.stream.amps.bindings:
  orders-in-0:
    consumer:
      filter: "/status = 'ACTIVE' AND /quantity > 100"

Bookmarks¶

`bookmarkType`¶

Type: BookmarkType enum
Default: DEFAULT
Values: DEFAULT, MOST_RECENT, EPOCH, NOW

Controls the starting bookmark for subscriptions.

Value	Behavior
`DEFAULT`	Use the AMPS client default (typically the beginning of the transaction log)
`MOST_RECENT`	Resume from the most recent bookmark stored by the bookmark store
`EPOCH`	Replay all messages from the beginning of the transaction log
`NOW`	Start from the current point in the transaction log (no replay)

spring.cloud.stream.amps.bindings:
  orders-in-0:
    consumer:
      bookmarkType: MOST_RECENT

`bookmarkProviderBeanName`¶

Type: String
Default: null

Name of a Spring bean implementing BookmarkProvider that supplies a custom initial bookmark string. When set, this overrides bookmarkType.

See Bookmarks for advanced bookmark scenarios.

Timing & Throughput¶

`rate`¶

Type: String
Default: null

Rate-limiting option for the subscription. Sets the maximum message delivery rate for a bookmark subscription. This option is only valid for bookmark subscriptions that do not use the live option. The rate can be specified as:

Number of messages per second (e.g., "1000")
Number of bytes per second (e.g., "100KB")
A multiple of the original replay rate (e.g., "1.5X")

`timeout`¶

Type: Duration
Default: null

Sets the timeout for the subscription command. If the client does not receive and consume a processed ack within the specified timeout, an exception is thrown. The timeout is monitored in the AMPS client, not on the server.

spring.cloud.stream.amps.bindings:
  orders-in-0:
    consumer:
      timeout: 30s

`batchSize`¶

Type: Integer
Default: null

Batch size for SOW queries. Sets the number of records returned in a batch during a SOW query.

`maxBacklog`¶

Type: Integer
Default: null

Formats the max_backlog option for a command, used when subscribing to a queue. When consuming from a queue, this option sets the maximum number of messages the client is willing to have outstanding at a given time.

Acknowledgment¶

`ackBatchSize`¶

Type: Integer
Default: null

Number of messages to accumulate before sending a batch ACK (which are sow_delete messages) to the server. When combined with maxBacklog and the AMPS server's MaxPerSubscriptionBacklog configuration, greater network efficiency can be achieved when using message queues. Setting this parameter causes calls to ack and successful auto-acks to be batched; unsuccessful/cancel acks are sent immediately. Default batch size is 1.

`ackTimeout`¶

Type: Duration
Default: null

Sets the ack timeout — the maximum time to let a success ack be cached before sending. Ensures acknowledgments are sent even if the batch isn't full.

spring.cloud.stream.amps.bindings:
  orders-in-0:
    consumer:
      ackBatchSize: 100
      ackTimeout: 5s

Heartbeat¶

`heartbeat`¶

Type: Duration
Default: null

Per-subscription heartbeat interval. Requests a server heartbeat and configures the client to close the connection if a heartbeat (or other activity) is not seen on the connection after two heartbeat intervals. This is separate from the binder-level heartBeatInterval.

Out-of-Focus (OOF)¶

`oof`¶

Type: boolean
Default: false

When true, enables Out-of-Focus (OOF) messages for SOW subscriptions. An OOF message is sent when a record no longer matches the subscription filter or has been deleted from the SOW cache.

Info

OOF messages are only meaningful for SOW-and-Subscribe subscriptions with a filter.

Timestamp¶

`withTimestamp`¶

Type: boolean
Default: false

When true, AMPS will include a header with the time at which AMPS processed the incoming publish command for this message. The timestamp is an ISO-8601 formatted string, propagated as the ampsTimestamp message header.

Custom Options¶

`options`¶

Type: String[]
Default: null

Additional AMPS command options to include in the subscription. Each string is added verbatim to the command's options.

spring.cloud.stream.amps.bindings:
  orders-in-0:
    consumer:
      options:
        - replace
        - no_empties

Concurrency¶

Consumer concurrency is controlled by the standard Spring Cloud Stream property:

spring:
  cloud:
    stream:
      bindings:
        orders-in-0:
          consumer:
            concurrency: 3

This creates 3 parallel AMPS connections for the binding, each subscribing to the same topic. See Concurrent Consumers for details.

Complete Example¶

spring:
  cloud:
    stream:
      amps:
        bindings:
          orders-in-0:
            consumer:
              sow: true
              filter: "/status = 'ACTIVE'"
              bookmarkType: MOST_RECENT
              rate: "50"
              ackBatchSize: 100
              ackTimeout: 5s
              heartbeat: 15s
              timeout: 30s
              oof: true
              withTimestamp: true
              batchSize: 200
              maxBacklog: 10000
              options:
                - replace
      bindings:
        orders-in-0:
          destination: orders
          group: order-service
          consumer:
            concurrency: 2

Consumer Properties¶

Subscription Mode¶

snapshot¶

sow¶

Content Filtering¶

filter¶

Bookmarks¶

bookmarkType¶

bookmarkProviderBeanName¶

Timing & Throughput¶

rate¶

timeout¶

batchSize¶

maxBacklog¶