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.
In cloud environments, _________ scaling refers to the automated process of adding or removing resources as needed.
- Elastic
- Horizontal
- Static
- Vertical
In cloud environments, Horizontal scaling refers to the automated process of adding or removing resources as needed, also known as scaling out or in.
An e-commerce website uses auto-scaling but faces downtime during sudden traffic spikes. What might be missing in their scaling strategy?
- Inadequate Database Scaling
- Inefficient Caching Strategy
- Insufficient Monitoring and Alerting
- Lack of Horizontal Scaling
Downtime during traffic spikes suggests a possible lack of horizontal scaling, where the application fails to dynamically add more instances to handle increased load. Monitoring and alerting can help detect such issues early.
What is the basic difference between horizontal scaling and vertical scaling?
- Distributing traffic
- Increasing resources on a server
- Increasing servers
- Load balancing
The basic difference is that horizontal scaling increases the number of servers to handle increased load, while vertical scaling involves increasing the resources (CPU, RAM) on a single server.
Which load balancing algorithm distributes requests based on the server with the least connections?
- Least Connections
- Random
- Round Robin
- Weighted Round Robin
The load balancing algorithm that distributes requests based on the server with the least connections is known as the Least Connections algorithm.
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.