How to query an Elasticsearch index using Pyspark and Dataframes
Elasticsaerch's documentation only covers loading a complete index to Spark.
from pyspark.sql import SQLContext
sqlContext = SQLContext(sc)
df = sqlContext.read.format("org.elasticsearch.spark.sql").load("index/type")
df.printSchema()
How can you perform a query to return data from an Elasticsearch index and load them to Spark as a DataFrame using pyspark?
Below is how I do it.
General environment settings and command:
export SPARK_HOME=/home/ezerkar/spark-1.6.0-bin-hadoop2.6
export PYSPARK_DRIVER_PYTHON=ipython2
./spark-1.6.0-bin-hadoop2.6/bin/pyspark --driver-class-path=/home/eyald/spark-1.6.0-bin-hadoop2.6/lib/elasticsearch-hadoop-2.3.1.jar
Code:
from pyspark import SparkConf
from pyspark.sql import SQLContext
conf = SparkConf().setAppName("ESTest")
sc = SparkContext(conf=conf)
sqlContext = SQLContext(sc)
q ="""{
"query": {
"filtered": {
"filter": {
"exists": {
"field": "label"
}
},
"query": {
"match_all": {}
}
}
}
}"""
es_read_conf = {
"es.nodes" : "localhost",
"es.port" : "9200",
"es.resource" : "titanic/passenger",
"es.query" : q
}
es_rdd = sc.newAPIHadoopRDD(
inputFormatClass="org.elasticsearch.hadoop.mr.EsInputFormat",
keyClass="org.apache.hadoop.io.NullWritable",
valueClass="org.elasticsearch.hadoop.mr.LinkedMapWritable",
conf=es_read_conf)
sqlContext.createDataFrame(es_rdd).collect()
You can also define data-frame columns. Refer Here for more info.
Hope that it helps!
I am running my code in a EMR cluster from Amazon using pyspark. Then, the way I made it work was following these steps:
1) Put this bootstrap action in the cluster creation (to create localhost elasticsearch server):
s3://awssupportdatasvcs.com/bootstrap-actions/elasticsearch/elasticsearch_install.4.0.0.rb
2) I run these commands to populate the elasticsearch database with some data:
curl -XPUT "http://localhost:9200/movies/movie/1" -d' {
"title": "The Godfather",
"director": "Francis Ford Coppola",
"year": 1972
}'
You can also run other curl commands if you wish, like:
curl -XGET http://localhost:9200/_search?pretty=true&q={'matchAll':{''}}
3) I inited pyspark using the following parameters:
pyspark --driver-memory 5G --executor-memory 10G --executor-cores 2 --jars=elasticsearch-hadoop-5.5.1.jar
I had downloaded the elasticsearch python client previously
4) I run the following code:
from pyspark import SparkConf
from pyspark.sql import SQLContext
q ="""{
"query": {
"match_all": {}
}
}"""
es_read_conf = {
"es.nodes" : "localhost",
"es.port" : "9200",
"es.resource" : "movies/movie",
"es.query" : q
}
es_rdd = sc.newAPIHadoopRDD(
inputFormatClass="org.elasticsearch.hadoop.mr.EsInputFormat",
keyClass="org.apache.hadoop.io.NullWritable",
valueClass="org.elasticsearch.hadoop.mr.LinkedMapWritable",
conf=es_read_conf)
sqlContext.createDataFrame(es_rdd).collect()
Then I finally got successful result from the command.
I have faced a issue similar to this to get geo-filtered data into a PySpark DataFrame. I am using elasticsearch-spark-20_2.11-5.2.2.jar with Spark version 2.1.1 and ES version 5.2. I was able to load the data into a DataFrame by specifying my query as an option while creating the DataFrame
My geo-query
q ="""{
"query": {
"bool" : {
"must" : {
"match_all" : {}
},
"filter" : {
"geo_distance" : {
"distance" : "100km",
"location" : {
"lat" : 35.825,
"lon" : -87.99
}
}
}
}
}
}"""
I used the following command to load data into DataFrame
spark_df = spark.read.format("es").option("es.query", q).load("index_name")
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