By default, Spark does not log all the events for block update. But you can configure it to log them. To do this, change the value of the property spark.eventLog.logBlockUpdates.enabled to true
val sc = new SparkContext(new SparkConf())
./bin/spark-submit <all your existing options> --spark.eventLog.logBlockUpdates.enabled=true
Note: This will increase the size of the log file too much and is not suggested.