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Production operations

HA

D8A supports running the HTTP receiver and the background worker separately, allowing HA setups.

Constraints:

Multiple receivers are supported.
Only a single worker is supported (session state lives in the worker's local BoltDB). Horizontal scaling of workers is not possible, so you're left with vertical scaling, but it shouldn't be a big problem—a machine with 16 cores and 30GB of RAM should handle traffic around 7K reqps, which translates to around 7B events/month. For ~100M traffic you should be good with 2 CPUs and 4GB of RAM.

Modes

d8a server: receiver + worker in one process (default).
d8a receiver: receiver only (HTTP server; publishes to queue).
d8a worker: worker only (consumes from queue; no HTTP server).

Queue backends

Two queue backends exist for the receiver/worker boundary:

filesystem (default): a local directory queue.
objectstorage: a shared object-storage-backed queue (Go CDK blob.Bucket).

When running multiple receivers on different nodes, use objectstorage.

Example: MinIO (S3-compatible)

YAML (config.yaml):

queue:
  backend: object_storage
  
  object_storage:
    prefix: d8a/dev/queue
    type: s3
    s3:
      host: 127.0.0.1
      port: 9000
      protocol: http
      bucket: d8a-queue
      access_key: minioadmin
      secret_key: minioadmin
      region: us-east-1
      create_bucket: true

Run receiver(s):

go run . receiver --config config.yaml --server-port 8080

Run the worker (single instance):

go run . worker --config config.yaml --storage-bolt-directory ./state

Notes:

Use queue.object_storage.prefix to namespace environments (prevents cross-talk within a shared bucket).
The system is at-least-once: tasks can be replayed if the worker crashes after processing but before deletion.

HA