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hdfs

Sends message parts as files to a HDFS directory.

# Common config fields, showing default values
output:
  label: ""
  hdfs:
    hosts: [] # No default (required)
    user: ""
    directory: "" # No default (required)
    path: ${!count("files")}-${!timestamp_unix_nano()}.txt
    max_in_flight: 64
    batching:
      count: 0
      byte_size: 0
      period: ""
      jitter: 0
      check: ""

Each file is written with the path specified with the 'path' field, in order to have a different path for each object you should use function interpolations described here.

Performance​

This output benefits from sending multiple messages in flight in parallel for improved performance. You can tune the max number of in flight messages (or message batches) with the field max_in_flight.

Fields​

hosts​

A list of target host addresses to connect to.

Type: array

# Examples

hosts: localhost:9000

user​

A user ID to connect as.

Type: string
Default: ""

directory​

A directory to store message files within. If the directory does not exist it will be created. This field supports interpolation functions.

Type: string

path​

The path to upload messages as, interpolation functions should be used in order to generate unique file paths. This field supports interpolation functions.

Type: string
Default: "${!count(\"files\")}-${!timestamp_unix_nano()}.txt"

max_in_flight​

The maximum number of messages to have in flight at a given time. Increase this to improve throughput.

Type: int
Default: 64

batching​

Allows you to configure a batching policy.

Type: object

# Examples

batching:
  byte_size: 5000
  count: 0
  period: 1s

batching:
  count: 10
  period: 1s

batching:
  check: this.contains("END BATCH")
  count: 0
  period: 1m

batching:
  count: 10
  jitter: 0.1
  period: 10s

batching.count​

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

Type: int
Default: 0

batching.byte_size​

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

Type: int
Default: 0

batching.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

batching.jitter​

A non-negative factor that adds random delay to batch flush intervals, where delay is determined uniformly at random between 0 and jitter * period. For example, with period: 100ms and jitter: 0.1, each flush will be delayed by a random duration between 0-10ms.

Type: float
Default: 0

# Examples

jitter: 0.01

jitter: 0.1

jitter: 1

batching.check​

A 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"

batching.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