Which strategy involves adding more servers to handle increased load in a web application?
- Horizontal scaling
- Load balancing
- Session management
- Vertical scaling
Horizontal scaling involves adding more servers to handle increased load in a web application by distributing the load across multiple machines.
To avoid thread safety issues, it's recommended to use __________ instead of instance variables in servlets.
- final variables
- global variables
- local variables
- static variables
Using static variables is recommended in servlets to avoid thread safety issues, as they are shared among all instances of the servlet and are stored in a shared memory space.
The _________ method should be used carefully in servlets due to potential thread safety issues.
- destroy()
- doGet()
- init()
- service()
The service() method should be used carefully in servlets due to potential thread safety issues. It handles requests and might result in multiple threads accessing the servlet concurrently, requiring careful consideration for thread safety.
A thread-safe servlet ensures that shared data is accessed in a _________ manner.
- parallel
- random
- sequential
- synchronized
A thread-safe servlet ensures that shared data is accessed in a synchronized manner. This prevents multiple threads from accessing the shared data simultaneously, reducing the risk of data corruption and ensuring proper thread safety.
In HTTP servlets, the _________ method is used to send error responses back to the client.
- doError()
- errorResponse()
- handleError()
- sendError()
The sendError() method in HTTP servlets is used to send error responses back to the client, providing information about the encountered error.
In a highly concurrent web application, how would you design a servlet to handle database connections securely and efficiently?
- Open a new database connection for each request.
- Store database connections as static variables.
- Use a connection pool to manage database connections.
- Use synchronized methods for database operations.
Using a connection pool is a best practice in highly concurrent applications as it efficiently manages and shares database connections, reducing the overhead of opening and closing connections for each request.
If a servlet manipulates a shared data structure, what must be done to ensure it operates correctly in a multithreaded environment?
- Avoid multithreading in servlets.
- Synchronize access to the shared data structure.
- Use multiple instances of the servlet.
- Use volatile keyword for the shared data structure.
Synchronizing access to the shared data structure is crucial in a multithreaded environment to prevent data corruption and ensure consistency. The synchronized keyword ensures that only one thread can access the shared data structure at a time.
In the context of web applications, what does the term 'sticky session' mean?
- A session that retains client affinity
- A session with a fixed duration
- A session with persistent data
- A session with secure connections
'Sticky session' refers to a session that retains client affinity, meaning requests from the same client are directed to the same server, enhancing user experience in stateful applications.
What is a common challenge when scaling stateful applications?
- Caching
- Data consistency
- Load balancing
- Stateless communication
Achieving Data consistency is a common challenge when scaling stateful applications, as it involves ensuring that data is synchronized across multiple instances of the application.
How does a distributed cache enhance the scalability of a web application?
- Decreases Cache Hit Rate
- Improves Session Management
- Increases Network Latency
- Reduces Database Load
A distributed cache reduces the load on the database by storing frequently accessed data, reducing the need to query the database, and thereby enhancing the scalability of a web application.