stream_write_json
Write JSON Stream
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_intervalandstream_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 {
# }