Reading structured streaming data from Elasticsearch into Spark using Python

Elastic Stack Elasticsearch
1

I believe Elasticsearch supports Spark Structured Streaming since version 6. I have seen examples of WRITING structured streaming data from spark to Elasticsearch in append mode. But I have not seen a single example of reading from Elasticsearch.

For example, here is how you write to ES:

query = df.writeStream \
.outputMode("append") \
.queryName("writing_to_es") \
.format("org.elasticsearch.spark.sql") \
.option("checkpointLocation", "/tmp/") \
.option("es.resource", "index/type") \
.option("es.nodes", "localhost") \
.start()

query.awaitTermination()

But how do you read from ES using spark structured streaming ? Please share an example .....

Thanks,
Saurab

2

Hi @saurab. As you mention, es-spark does support writing to Elasticsearch with spark structured streaming. But it does not support reading from Elasticsearch as a spark structured streaming source.

3

Here is the ticket for the work -- Support Spark Structured Streaming read from ES · Issue #1227 · elastic/elasticsearch-hadoop · GitHub. The problem is that we currently don't have an efficient way to listen for changes to an Elasticsearch index.