update spark, add 2.3.1

spark/2.3.1/README.md

@@ -0,0 +1,64 @@
+# Deploy Spark Cluster of standalone mode
+
+## Master
+
+```bash
+docker service create \
+	--name spark-master \
+	--hostname spark-master \
+	--network swarm-net \
+	--replicas 1 \
+	--detach true \
+	--endpoint-mode dnsrr \
+	newnius/spark:2.3.1 master
+```
+
+## Slaves
+
+```bash
+docker service create \
+	--name spark-slave \
+	--network swarm-net \
+	--replicas 5 \
+	--detach true \
+	--endpoint-mode dnsrr \
+	newnius/spark:2.3.1 slave spark://spark-master:7077
+```
+
+## Validate installation
+
+#### spark-submit PI
+
+```bash
+spark-submit \
+	--master spark://spark-master:7077 \
+	--deploy-mode cluster \
+	--class org.apache.spark.examples.JavaSparkPi \
+	./examples/jars/spark-examples_2.11-2.3.1.jar 100
+```
+
+#### spark-shell HDFS wordcount
+
+Enter `spark-shell --master spark://spark-master:7077` to enter shell.
+
+```shell
+val lines = sc.textFile("hdfs://hadoop-master:8020/user/root/input")
+
+val words = lines.flatMap(_.split("\\s+"))
+
+val wc = words.map(word => (word, 1)).reduceByKey(_ + _)
+
+wc.collect()
+
+val cnt = words.map(word => 1).reduce(_ + _)
+```
+
+## Browse the web UI
+
+You can expose the ports in the script, but I'd rather not since the slaves shoule occupy the same ports.
+
+To access the web UI, deploy another (socks5) proxy to route the traffic.
+
+If you don't one, try [newnius/docker-proxy](https://hub.docker.com/r/newnius/docker-proxy/), it is rather easy to use.
+
+Visit [spark-master:8080](http://spark-master:8080) to view the cluster.