A high-traffic website uses a cache that frequently encounters 'cache churn'. What strategy can be used to minimize this effect?
- Bloom Filters
- Cache Sharding
- Least Recently Used (LRU) Caching
- Write-Behind Caching
Using Least Recently Used (LRU) caching strategy helps minimize cache churn by retaining frequently used items in the cache and discarding the least recently used ones, optimizing cache efficiency for a high-traffic website.
An online content platform uses caching to improve user experience. However, users in different regions report varying latency. What caching approach can be adopted to optimize for all users?
- Content Delivery Network (CDN) Caching
- Local Caching
- Proxy Caching
- Write-Through Caching
Adopting Content Delivery Network (CDN) caching helps optimize user experience for users in different regions by distributing cached content to edge servers, reducing latency and enhancing content delivery speed globally.
A servlet needs to log different levels of messages. Which approach is the most effective?
- Print messages to the console
- Use System.out.println()
- Use a logging framework like Log4j
- Write messages to a file
Using a logging framework like Log4j is the most effective approach for logging in a servlet as it provides flexibility, configurability, and allows logging at different levels.
How can a servlet invalidate a cookie that has been sent to the client?
- By calling response.expireCookie()
- By setting the cookie to null
- By setting the cookie's Max-Age to 0
- By using request.removeCookie()
A servlet can invalidate a cookie by setting its Max-Age attribute to 0, indicating that the cookie has expired, and the client should discard it.
How do you handle an unchecked exception in a servlet?
- Configure error-page in web.xml
- Log the exception using a logging framework
- Throw ServletException
- Use a try-catch block in doGet()
Configuring an error-page in the web.xml file is a common practice to handle unchecked exceptions in a servlet. It allows you to specify an error page that should be displayed in case of an exception.
In a servlet, how can you log an exception along with the stack trace?
- Log using ServletContext.log()
- System.out.println(exception)
- Use a logging framework like Log4j
- response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR)
Using a logging framework like Log4j is the best practice for logging exceptions along with their stack traces in a servlet. This provides more control and flexibility in managing log statements.
What is the best practice for handling sensitive data in servlet log files?
- Disable logging of sensitive data
- Encrypt log files
- Obfuscate sensitive information before logging
- Use a secure logging framework
The best practice for handling sensitive data in servlet log files is to obfuscate the information before logging. This ensures that sensitive details are not exposed in logs, maintaining security and compliance with data protection regulations.
The ________ method of the HttpServletResponse object is used to send an error response to the client with a status code and a descriptive message.
- errorResponse()
- sendError()
- sendResponse()
- writeError()
The sendError() method of the HttpServletResponse object is used to send an error response to the client with a specified status code and a descriptive message.
In servlets, the _________ framework can be used for advanced error handling and logging.
- ErrorLog
- ExceptionHandling
- Filter
- Log4j
In servlets, the Log4j framework can be used for advanced error handling and logging. Log4j provides a flexible logging framework for Java applications.
Custom error pages in servlets are configured in the _________ file.
- config.xml
- custom-error.xml
- error-pages.xml
- web.xml
Custom error pages in servlets are configured in the web.xml file. This file allows you to specify error pages for different HTTP status codes, providing custom error handling in your web application.