PROCESSES

What is the basic idea behind threads in a distributed system?

• Threads are physical processors

• Threads are software processors that execute a series of instructions

• Threads are used for blocking I/O operations

• Threads are used for process switching

What is the minimal collection of values stored in registers and memory used for the execution of a series of instructions in a thread context?

• Processor context

• Thread context

• MMU register values

• Process context

Why are threads used in a multithreaded process?

• To avoid process switching

• To structure large applications as a collection of processes

• To avoid blocking I/O operations

• To exploit parallelism

What is a direct cost of a context switch?

• Executing code of the handler

• Accessing block D

• Messing up the cache

• Actual switch and executing code of the handler

What is the main issue when deciding whether an OS kernel should provide threads?

• Performance gain vs. increased complexity

• Complexity of the kernel

• Support for user-level threads

• Efficiency of thread operations

What is the principle operation of user and kernel threads combined?

• Kernel schedules another kernel thread with a runnable user thread

• User thread does system call, kernel thread blocks

• User thread calls a blocking user-level operation

• Kernel thread remains idle when no user threads to schedule

How does a multithreaded web client hide network latencies?

• By reacting to next request while previous one is being replied

• By avoiding process switching

• By exploiting parallelism

• By switching CPU to another thread

What is the principle of virtualization based on?

• Isolation of components

• Ease of portability

• Hardware changes

• Mimicking interfaces

What is the main reason for using containers in distributed systems?

• Load distribution

• Privacy and security

• Flexibility in code migration

• Performance of migrating virtual machines

What is the main problem when migrating code in heterogeneous systems?

• Hardware compatibility

• Lack of virtualization

• Data transfer speed

• Dependency on local hardware and OS