Common Spark Troubleshooting

This text discusses common issues faced by new Apache Spark users and provides solutions to these problems. The most common error is the "Initial job has not accepted any resources" warning, which occurs when an application requests more resources from the cluster than it can provide. To resolve this issue, users should ensure they are not requesting more resources than exist or shut down unnecessary applications using resources. Another common problem is Out-of-Memory (OOM) errors on Spark executors due to excessive information being cached in memory. Solutions include setting the spark.cleaner.ttl variable and adjusting the SPARK_JAVA_OPTS variable. Class not found issues can be resolved by using a fat Jar containing all dependencies or ensuring that library versions match between the application and Spark server. The text also provides a brief walkthrough of the Spark UI, which displays information about the current state of applications running on the cluster.