Write JSON Stream

Writes a Spark dataframe stream into a JSON stream.

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

Examples

if (FALSE) { sc <- spark_connect(master = "local") dir.create("json-in") jsonlite::write_json(list(a = c(1,2), b = c(10,20)), "json-in/data.json") json_path <- file.path("file://", getwd(), "json-in") stream <- stream_read_json(sc, json_path) %>% stream_write_json("json-out") stream_stop(stream) }