Fiendish Java Quiz

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Fiendish Java Quiz

Test your knowledge of Java Virtual Machine arguments and performance tuning with our Fiendish Java Quiz! This quiz is designed for Java developers looking to deepen their understanding of JVM options and configurations.

You'll explore:

VM arguments
JVM heap size settings
Performance tuning flags
Garbage collection options

13 Questions3 MinutesCreated by DebuggingGuru347

Which of these is a valid Java VM argument?

-XX:+UseParallelOldGC

-XX:+UseParallelGC

-XX:+UseParallelNewGC

This options should be specified when a large JVM heap is required (greater than 4 Gytes) and the architecture is 64-bit.

-XX64

-XX:+h64

-d64

What does this flag do: -XX:+HeapDumpOnOutOfMemoryError

Used to issue emergency commands to be executed in case of out of memory error

Instructs the JVM to dump heap into physical file in case of OutOfMemoryError

Set policy that limits the proportion of the VM's time that is spent in GC before an OutOfMemory error is thrown

Is this program tuned for Higher Throughput or Lower Response time: java -server -XX:+UseParallelGC -XX:+UseLargePages -Xmn10g -Xms26g -Xmx26g

Higher Throughput

Lower Response Time

What does this do: -XX:NewSize=512M

Resets JVM heap size on completion of initial pass

Sets the CMS garbage collector

Sets size of JVM Young generation

Which of these is NOT a valid Java VM argument?

-XX:BleedMemOnMax=false

-XX:MaxGCPauseMillis=500

-XX:+AlwaysPreTouch

-XX:MaxMetaspaceSize sets the maximum amount of native memory that can be allocated for the class metadata. But what is its default?

Same as -Xms

Unlimited

Platform dependent

What does this do? java -XX:DumpLoadedClassList=hello.classlist Hello

Recompiles only classes referenced by the Hello application

Create a list of all classes used by the Hello application

Runs the Hello application but with classpath specified by hello.classlist

What does the jps command do?

List the instrumented JVMs on the target system

Start a graphical console to monitor and manage Java applications

Monitor the creation and termination of instrumented Java HotSpot VMs

The -server flag selects server application runtime optimizations. But what does this do?

Prevents external applications from forcing expensive garbage collections.

The directory server will be more aggressively optimized to produce higher throughput.

Selects a low initial JVM heap size for an application.

Fiendish Java Quiz

Fiendish Java Quiz

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