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Showing posts from April, 2020

JVM Garbage Collection and Optimizations

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Overview When troubleshooting systems for performance-related issues, memory optimizations are a place that needs a deep analysis of what each system stores in the memory, how long those are stored, and access patterns. This post is to keep a note on the background information and valuable points to note in such an effort, specific to Java-based implementations as a deep understanding of the JVM behaviors is very beneficial in the process.

Java language provides much convenience to the developers by taking care of the memory management to a great extent letting the focus be on the rest of the logic. Still having a good understanding of how Java does this underneath, rationalize several best practices we follow in Java implementations and help design the programs better and think seriously on some aspects that can later lead to memory leaks and system stability in the long run. Java Garbage Collector has a big role in this been responsible for freeing up memory by removing memory gar…

JVM Garbage Collection and Optimizations

Image
Overview When troubleshooting systems for performance-related issues, memory optimizations are a place that needs a deep analysis of what each system stores in the memory, how long those are stored, and access patterns. This post is to keep a note on the background information and valuable points to note in such an effort, specific to Java-based implementations as a deep understanding of the JVM behaviors is very beneficial in the process.

Java language provides much convenience to the developers by taking care of the memory management to a great extent letting the focus be on the rest of the logic. Still having a good understanding of how Java does this underneath, rationalize several best practices we follow in Java implementations and help design the programs better and think seriously on some aspects that can later lead to memory leaks and system stability in the long run. Java Garbage Collector has a big role in this been responsible for freeing up memory by removing memory gar…

Tomcat JDBC Pool - Connection Leak - Catch the Culprit

Database connection leaks are something that can stay hidden unless paid specific attention and would come to the surface at the most critical stages at a peak time of the system. We would manually check if all the open connections have been closed properly. Then we have various code quality plugins that would scan and check for that. Still when the connections are passed through a complex structure of program both of these can miss a possible connection leak. Then at unit test or integration test levels, we can have checks to validate the counts in the connection pool to avoid this unfortunate situation, that would keep engineers busy at year-end, black Friday, etc. :)
In the unfortunate case of hitting with a performance degrade or a total crash of the system which can be propagated via a JDBC connection leak, when we suspect a connection leak, how easily and quickly isolate the culprit. In the Tomcat connection pool, we can do this using 3 properties.
removeAbandoned If a DB connec…