I have a Java snippet that reads records from a remote Oracle DB (atleast 65k records). Essentially, we are trying to pass the hourly filter to the dataframe to fetch the records, on an hourly partition x 24.
The source view is based on a table with millions of records.
The problem we are facing is that, Spark (on YARN or as a SPARK cluster) processes 22 out of 24 partitions in under 3 mins. The last 2 partitions are taking more than 5 hours to complete.
Is there any way we can speed this up using DataFrames ?
HashMap<String, String> options = new HashMap<>();
sqlContext.setConf("spark.sql.shuffle.partition", "50");
options.put("dbtable", "( select * from "+VIEW_NAME+" where 1=1)");
options.put("driver", "oracle.jdbc.OracleDriver");
options.put("url", JDBC_URL);
options.put("partitionColumn", "hrs");
options.put("lowerBound", "00");
options.put("upperBound", "23");
options.put("numPartitions", "24");
DataFrame dk = sqlContext.load("jdbc", options).cache();
dk.registerTempTable(VIEW_NAME);
dk.printSchema();
DateTime dt = new DateTime(2015, 5, 8, 10, 0, 0);
String s = SQL_DATE_FORMATTER.print(dt);
dt = dt.plusHours(24);
String t = SQL_DATE_FORMATTER.print(dt);
System.out.println("S is " + s + "and t is "+ t);
Stream<Row> rows = dk.filter("DATETIME >= '" + s + "' and DATETIME <= '" + t + "'").collectAsList().parallelStream();
System.out.println("Collected" + rows.count());
