sparklyr (version 0.9.2)

stream_write_json: Write JSON Stream

Description

Writes a Spark dataframe stream into a JSON stream.

Usage

stream_write_json(x, path, mode = c("append", "complete", "update"),
  trigger = stream_trigger_interval(), checkpoint = file.path(path,
  "checkpoints", random_string("")), options = list(), ...)

Arguments

x

A Spark DataFrame or dplyr operation

path

The destination path. Needs to be accessible from the cluster. Supports the "hdfs://", "s3a://" and "file://" protocols.

mode

Specifies how data is written to a streaming sink. Valid values are "append", "complete" or "update".

trigger

The trigger for the stream query, defaults to micro-batches runnnig every 5 seconds. See stream_trigger_interval and stream_trigger_continuous.

checkpoint

The location where the system will write all the checkpoint information to guarantee end-to-end fault-tolerance.

options

A list of strings with additional options.

...

Optional arguments; currently unused.

See Also

Other Spark stream serialization: stream_read_csv, stream_read_jdbc, stream_read_json, stream_read_kafka, stream_read_orc, stream_read_parquet, stream_read_text, stream_write_csv, stream_write_jdbc, stream_write_kafka, stream_write_memory, stream_write_orc, stream_write_parquet, stream_write_text

Examples

# NOT RUN {
sc <- spark_connect(master = "local")

dir.create("json-in")
jsonlite::write_json(list(a = c(1,2), b = c(10,20)), "../streaming/json-in/data.json")

stream <- stream_read_json(sc, "json-in") %>% stream_write_json("json-out")

stop_stream(stream)

# }
# NOT RUN {
# }