Java Tutorials

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I have written a lot of java tutorials here into many categories. Some of them are in core java tutorial whereas some of them are in J2EE tutorial or Java EE tutorial area. As the number of posts grows, keeping track of them becomes harder. So I have provided a summary post for most of the categories where you can read them in the order for better understanding.

Java Tutorials

This post is aimed to include all the summary posts in java tutorials that you should go through to have a clear understanding of that area.

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What is Garbage collection in Spark and its impact and resolution

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Garbage Collection Spark runs on the Java Virtual Machine (JVM). Because Spark can store large amounts of data in memory, it has a major reliance on Java’s memory management and garbage collection (GC). Therefore, garbage collection  (GC) can be a major issue that can affect many Spark applications. Common symptoms of excessive GC in Spark are: Slowness of application Executor heartbeat timeout GC overhead limit exceeded error Spark’s memory-centric approach and data-intensive applications make it a more common issue than other Java applications. Thankfully, it’s easy to diagnose if your Spark application is suffering from a GC problem. The Spark UI marks executors in red if they have spent too much time doing GC. Spark executors are spending a significant amount of CPU cycles performing garbage collection. This can be determined by looking at the “Executors” tab in the Spark application UI. Spark will mark an executor in  red  if the executor has spent more than 10% of the time in gar...
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Window function in PySpark with Joins example using 2 Dataframes (inner join)

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