When optimizing memory usage in a Java application, what strategies should be considered?
- Disable JIT compilation
- Disable garbage collection
- Increase object creation
- Use data structures efficiently
Efficient use of data structures is crucial for memory optimization. Disabling garbage collection, increasing object creation, and disabling JIT compilation are not recommended strategies and can negatively impact memory usage.
When implementing a servlet to handle form data from a dynamically generated form with varying field names, what strategy should be employed?
- Ignore dynamic form fields for security
- Iterate through request parameters
- Use fixed field names for all form elements
- Use hidden fields to store dynamic names
The recommended strategy is to iterate through request parameters, allowing dynamic handling of varying field names in a dynamically generated form. This approach ensures that all form data, regardless of field names, can be processed dynamically.
In a high-performance Java application, how should memory management be approached to prevent latency issues?
- Frequent use of finalize method
- Implement lazy loading for classes
- Opt for a large heap size
- Utilize efficient garbage collectors
Utilizing efficient garbage collectors is essential for high-performance applications. Implementing lazy loading, opting for a large heap size, and frequent use of the finalize method can lead to latency issues and should be avoided in performance-sensitive applications.
What is the primary purpose of caching in web applications?
- To add security
- To design the user interface
- To handle user authentication
- To improve performance
The primary purpose of caching in web applications is to improve performance by storing frequently accessed data and reducing the need to fetch it from the original source repeatedly.
Which caching strategy involves storing frequently accessed data in memory for quick retrieval?
- Browser caching
- Database caching
- In-memory caching
- Page caching
In-memory caching involves storing frequently accessed data in the system's memory, enabling quick retrieval and enhancing performance.
Which HTTP header is commonly used to control cache behavior in web browsers?
- Cache-Control
- Content-Encoding
- Expires
- Last-Modified
The Cache-Control header is commonly used to control cache behavior in web browsers by specifying directives for caching mechanisms in both requests and responses.
In distributed systems, what is a cache stampede and how is it typically mitigated?
- A cache stampede is a networking issue that results in delayed cache updates.
- A cache stampede is a planned event in which caches are forcibly cleared and refreshed simultaneously.
- A cache stampede is an outdated concept and is no longer relevant in modern distributed systems.
- A cache stampede is when multiple processes or nodes simultaneously attempt to load the same cache entry that is currently not in the cache.
A cache stampede occurs when multiple processes try to load the same cache entry simultaneously. It is typically mitigated by using cache locks, semaphore mechanisms, or by allowing only one process to regenerate the cache entry.
How does 'cache eviction' differ from 'cache invalidation' in caching strategies?
- Remove all items
- Remove least frequently used items
- Remove least recently used items
- Remove outdated items
In caching strategies, 'cache eviction' involves removing the least recently used or least frequently used items, while 'cache invalidation' is about removing outdated items.
In caching strategies, what is meant by 'cache warming'?
- Caching based on user preferences
- Clearing cache to improve performance
- Dynamically adjusting cache size
- Pre-loading cache with frequently used items
'Cache warming' in caching strategies refers to pre-loading the cache with frequently used items, optimizing performance by ensuring that the cache is populated with data that is likely to be requested.
What is a 'Content Delivery Network (CDN)' and how does it relate to caching?
- A mechanism for cache synchronization
- A protocol for cache communication
- A type of caching algorithm
- Network of distributed servers for content delivery
A 'Content Delivery Network (CDN)' is a network of distributed servers designed to deliver content efficiently. It relates to caching by strategically placing content on servers closer to end-users, reducing latency and improving performance through localized caching.