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memory

Tags: In Memory

Stores consumed messages in memory and acknowledge them at the input level. During a shutdown, Benthos will make the best attempt at flushing all remaining messages before exiting cleanly.

YAML Configurations

Common Config

# Common config fields, showing default values
buffer:
  memory:
    limit: 524288000
    batch_policy:
      enabled: false
      count: 0
      byte_size: 0
      period: ""
      check: ""

Advanced Config

# All config fields, showing default values
buffer:
  memory:
    limit: 524288000
    batch_policy:
      enabled: false
      count: 0
      byte_size: 0
      period: ""
      check: ""
      processors: []

This buffer is appropriate when consuming messages from inputs that do not gracefully handle back pressure and where delivery guarantees aren't critical.

This buffer has a configurable limit, where consumption will be stopped with back pressure upstream if the total size of messages in the buffer reaches this amount. Since this calculation is only an estimate, and the real size of messages in RAM is always higher, it is recommended to set the limit significantly below the amount of RAM available.

Delivery Guarantees

This buffer intentionally weakens the delivery guarantees of the pipeline and, therefore, should never be used in places where data loss is unacceptable.

Batching

It is possible to batch up messages sent from this buffer using a batch policy.

Fields

limit

The maximum buffer size (in bytes) to allow before applying backpressure upstream.

Type: int

Default: 524288000


batch_policy

Optionally configure a policy to flush buffered messages in batches.

Type: object


batch_policy.enabled

Whether to batch messages as they are flushed.

Type: bool

Default: false


batch_policy.count

A number of messages at which the batch should be flushed. If 0 disables count-based batching.

Type: int

Default: 0


batch_policy.byte_size

An amount of bytes at which the batch should be flushed. If 0 disables size-based batching.

Type: int

Default: 0


batch_policy.period

A period in which an incomplete batch should be flushed regardless of its size.

Type: string

Default: ""

# Examples

period: 1s

period: 1m

period: 500ms

batch_policy.check

Bloblang query that should return a boolean value indicating whether a message should end a batch.

Type: string

Default: ""

# Examples

check: this.type == "end_of_transaction"

batch_policy.processors

A list of processors to apply to a batch as it is flushed. This allows you to aggregate and archive the batch however you see fit. Please note that all resulting messages are flushed as a single batch, therefore splitting the batch into smaller batches using these processors is a no-op.

Type: array

# Examples

processors:
  - archive:
      format: concatenate

processors:
  - archive:
      format: lines

processors:
  - archive:
      format: json_array