Bookmarks

AMPS bookmarks enable durable subscriptions — the ability to resume message consumption from a specific point in the transaction log, even after a client restart.

Bookmark Types

The bookmarkType consumer property controls the starting position for a subscription.

DEFAULT

Uses the AMPS client default behavior. Typically starts from the beginning of the transaction log for new subscriptions, or from the last stored bookmark for resuming subscriptions.

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

MOST_RECENT

Resumes from the most recent bookmark stored in the bookmark store. This is the typical choice for durable subscriptions that should pick up where they left off.

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

Tip

For MOST_RECENT to work correctly across restarts, use a persistent bookmark store (not the default in-memory store).

EPOCH

Replays all messages from the beginning of the transaction log. Useful for rebuilding state or reprocessing.

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

NOW

Starts from the current point in the transaction log. No historical messages are replayed. Only messages published after the subscription is established are received.

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

Bookmark Store

The bookmark store persists the last-consumed bookmark for each subscription. On reconnection or restart, the client can resume from the stored bookmark.

Default (In-Memory)

By default, the binder uses a MemoryBookmarkStore. Bookmarks are lost when the application stops.

Persistent Store

For durable bookmarks, provide a custom BookmarkStoreProvider bean:

@Bean
public BookmarkStoreProvider myBookmarkStore() {
    return () -> new LoggedBookmarkStore("./data/bookmarks");
}

Then reference it in the binder configuration:

spring.cloud.stream.amps.binder:
  subscriptionBookmarkStoreProviderBeanName: myBookmarkStore

Custom Bookmark Provider

For advanced scenarios where you need full control over the initial bookmark value, implement the BookmarkProvider interface:

@Bean
public BookmarkProvider customBookmarkProvider() {
    return () -> {
        // Return a specific bookmark string, e.g., from a database
        return myDatabase.getLastProcessedBookmark("orders");
    };
}

Reference it in the consumer configuration:

spring.cloud.stream.amps.bindings:
  orders-in-0:
    consumer:
      bookmarkProviderBeanName: customBookmarkProvider

Note

When bookmarkProviderBeanName is set, it takes precedence over bookmarkType.

Resolution Order

The binder resolves the initial bookmark in this order:

1. bookmarkProviderBeanName — If set, the bean's bookmark is used.
2. bookmarkType — Maps to the corresponding AMPS Client.Bookmarks.* constant.
3. Fallback — DEFAULT (AMPS client default).

Example: Durable Subscription with Persistent Bookmarks

@Configuration
public class BookmarkConfig {

    @Bean
    public BookmarkStoreProvider persistentBookmarkStore() {
        return () -> new LoggedBookmarkStore("./data/bookmarks");
    }
}

spring:
  cloud:
    stream:
      amps:
        binder:
          brokers:
            - tcp://amps-server:50000/json
          subscriptionBookmarkStoreProviderBeanName: persistentBookmarkStore
        bindings:
          orders-in-0:
            consumer:
              bookmarkType: MOST_RECENT
              sow: true
      bindings:
        orders-in-0:
          destination: orders
          group: order-processor