How can a hash flooding attack impact the performance of a web server using a hashmap to store session data?
It has no impact on performance, as hash flooding attacks only target data integrity.
It can cause a denial-of-service by forcing the server to handle a large number of collisions.
It can lead to increased memory usage and faster response times.
It can improve the efficiency of the hashmap by distributing data more evenly.
In the context of hash tables, what does a high load factor indicate?
A more efficient hash function is being used.
Lower memory usage.
Faster insertion operations.
A higher probability of collisions.
Which of the following is NOT a valid mitigation strategy against hash flooding attacks?
Employing a bloom filter to quickly identify and discard potentially malicious input.
Switching to a different data structure like a tree-based map that offers consistent performance.
Implementing a random salt value in the hash function to make collisions unpredictable.
Using a fixed-size hashmap to limit the maximum number of collisions.
You are designing a system to store and retrieve frequently accessed data with high performance. Which of the following hash table collision resolution strategies would generally offer the BEST performance under high load factors?
Double Hashing
Separate Chaining
Quadratic Probing
Linear Probing
Hopscotch hashing aims to improve the performance of open addressing by:
Using multiple hash tables to store keys with different hash values.
Using a dynamic array to resize the table when the load factor gets high.
Employing a binary search tree for efficient collision resolution.
Limiting the maximum distance a key can be placed from its original hash index.
What mechanism does Java's ConcurrentHashMap employ to allow for concurrent reads and updates while maintaining thread safety?
Read-write locks separating readers and writers
A single global lock for all operations
Lock-free data structures using atomic operations
Fine-grained locking at the bucket level
What is a common disadvantage of using a hashmap with a poorly chosen hash function?
Slow key generation
Inability to handle duplicate keys
Frequent hash collisions
Increased memory usage
Which of these data structures can provide a more secure and performant alternative to a hashmap when handling user authentication data, especially in scenarios prone to hash flooding attacks?
Array
Queue
Linked list
Tree
You are implementing an LRU (Least Recently Used) cache with a fixed capacity. Which data structure combination would be most suitable for efficiently managing the cache?
Binary Search Tree + Heap
Hashmap + Stack
Hashmap + Doubly Linked List
Array + Queue
What is the primary reason for using a prime number as the size of a hash table in many implementations?
To make the implementation of the hash table simpler.
To minimize the memory usage of the hash table.
To increase the speed of hash function computation.
To ensure an even distribution of keys across the hash table, reducing collisions.