IN Apache Beam how to handle exceptions/errors at Pipeline-IO level - apache-spark

Question

i am using running spark runner as pipeline runner in apache beam and found an error.
by getting the error, my question araised. I know the error was due to incorrect Column_name in sql query but my question is how to handle an error/exception at IO level
org.apache.beam.sdk.util.UserCodeException: java.sql.SQLSyntaxErrorException: Unknown column 'FIRST_NAME' in 'field list'
at org.apache.beam.sdk.util.UserCodeException.wrap(UserCodeException.java:36)
at org.apache.beam.sdk.io.jdbc.JdbcIO$ReadFn$DoFnInvoker.invokeProcessElement(Unknown Source)
at org.apache.beam.runners.core.SimpleDoFnRunner.invokeProcessElement(SimpleDoFnRunner.java:185)
at org.apache.beam.runners.core.SimpleDoFnRunner.processElement(SimpleDoFnRunner.java:149)
at org.apache.beam.runners.spark.translation.DoFnRunnerWithMetrics.processElement(DoFnRunnerWithMetrics.java:70)
at org.apache.beam.runners.spark.translation.SparkProcessContext$ProcCtxtIterator.computeNext(SparkProcessContext.java:145)
at org.apache.beam.repackaged.beam_runners_spark.com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:145)
at org.apache.beam.repackaged.beam_runners_spark.com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:140)
at scala.collection.convert.Wrappers$JIteratorWrapper.hasNext(Wrappers.scala:42)
at scala.collection.Iterator$$anon$13.hasNext(Iterator.scala:461)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408)
at org.apache.spark.storage.memory.MemoryStore.putIteratorAsValues(MemoryStore.scala:216)
at org.apache.spark.storage.BlockManager$$anonfun$doPutIterator$1.apply(BlockManager.scala:1092)
at org.apache.spark.storage.BlockManager$$anonfun$doPutIterator$1.apply(BlockManager.scala:1083)
at org.apache.spark.storage.BlockManager.doPut(BlockManager.scala:1018)
18/11/01 13:13:16 WARN org.apache.spark.scheduler.TaskSetManager: Lost task 3.0 in stage 0.0 (TID 3, localhost, executor driver): org.apache.beam.sdk.util.UserCodeException: java.sql.SQLSyntaxErrorException: Unknown column 'FIRST_NAME' in 'field list'
at org.apache.beam.sdk.util.UserCodeException.wrap(UserCodeException.java:36)
at org.apache.beam.sdk.io.jdbc.JdbcIO$ReadFn$DoFnInvoker.invokeProcessElement(Unknown Source)
at org.apache.beam.runners.core.SimpleDoFnRunner.invokeProcessElement(SimpleDoFnRunner.java:185)
at org.apache.beam.runners.core.SimpleDoFnRunner.processElement(SimpleDoFnRunner.java:149)
at org.apache.beam.runners.spark.translation.DoFnRunnerWithMetrics.processElement(DoFnRunnerWithMetrics.java:70)
at org.apache.beam.runners.spark.translation.SparkProcessContext$ProcCtxtIterator.computeNext(SparkProcessContext.java:145)
at org.apache.beam.repackaged.beam_runners_spark.com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:145)
at org.apache.beam.repackaged.beam_runners_spark.com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:140)
at scala.collection.convert.Wrappers$JIteratorWrapper.hasNext(Wrappers.scala:42)
at scala.collection.Iterator$$anon$13.hasNext(Iterator.scala:461)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408)
..............
at org.apache.spark.rdd.RDD.getOrCompute(RDD.scala:335)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:286)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87)
at org.apache.spark.scheduler.Task.run(Task.scala:109)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:345)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.sql.SQLSyntaxErrorException: Unknown column 'FIRST_NAME' in 'field list'
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:536)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:513)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:115)
at com.mysql.cj.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:1983)
at com.mysql.cj.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1826)
at com.mysql.cj.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1923)
at org.apache.commons.dbcp2.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:83)
at org.apache.commons.dbcp2.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:83)
at org.apache.commons.dbcp2.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:83)
at org.apache.commons.dbcp2.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:83)
at org.apache.beam.sdk.io.jdbc.JdbcIO$ReadFn.processElement(JdbcIO.java:601)

Answer 1

You have to create a custom excetpion handler class to catch that exception for eg;
need to implement a custom method like this
public Mycust_Exception(String string) {
super("Error Obtained by "+string);
}
here i have just returned the string but can also throw using super() and now you need to declare try-catch blocks where you expect to have exception and also follow PTranformation_level_exceptionHandler_implementation
and call the throw statement like this in catch block
throw new Ezflow_Exception("Invalid statement");
this implementation can surely satisfy your query mostly.
for Java programing it is one of most common way to implement