In a distributed system handling high-frequency, low-latency updates for a financial trading platform, which communication pattern, if improperly implemented, is most likely to introduce significant 'head-of-line blocking' issues on the client-side due to the sequential processing of message frames, even with concurrent network I/O?

WebSockets with ordered message delivery guarantees

Traditional Polling with short intervals

Long-Polling with a single active request

Webhooks delivering events to a message queue

Which of the following statements accurately describe the architectural implications and characteristics of Long-Polling compared to traditional Polling?

Long-Polling significantly reduces the number of HTTP requests made by the client over a given period when updates are infrequent.

Long-Polling requires the client to establish a new TCP connection for each new event notification received.

Long-Polling consumes less server-side CPU and memory resources per client when updates are continuous and frequent.

Long-Polling is generally more susceptible to network latency fluctuations, leading to higher perceived delays in event delivery.

Which of the following statements regarding the server-side resource utilization for a large number of concurrent clients waiting for updates are generally true when comparing different real-time communication patterns?

WebSockets typically consume less CPU per active connection than Long-Polling due to reduced HTTP header overhead after the initial handshake.

Traditional Polling, even with optimized intervals, usually leads to higher server-side I/O operations due to frequent request/response cycles.

Webhooks, as a push mechanism, inherently offload client-polling server resources to the webhook receiver's infrastructure.

Long-Polling tends to hold more open TCP connections on the server compared to WebSockets if the event frequency is very low across all clients.

A real-time analytics dashboard processes incoming data streams and needs to display updates to browser clients with sub-second latency. The data rate can vary significantly, from occasional bursts to sustained high frequency. Which pattern offers the MOST optimal balance between latency, server scalability, and network bandwidth efficiency under these fluctuating conditions, assuming modern browser support and server infrastructure?

Traditional Polling with adaptive intervals

Long-Polling with aggressive timeouts

For which of the following characteristics or requirements would Webhooks be a suitable and potentially advantageous communication pattern?

Decoupling the event producer from the event consumer, promoting independent evolution of services.

Allowing a third-party service to notify your application whenever a specific event occurs within their system.

Reducing the number of open connections maintained by your server when consuming real-time data from an external API.

Enabling real-time, bidirectional chat functionality between two end-users.

A legacy system uses traditional polling to fetch updates every 5 seconds. The business requirement changes to 'receive updates within 200 milliseconds of occurrence'. Adopting Long-Polling is proposed. Which of the following challenges are most likely to emerge during the transition or operation of Long-Polling in this scenario?

Potential for server-side resource exhaustion due to a high number of concurrently open connections.

The need for more robust server-side logic to queue events for clients whose requests are still pending.

Increased client-side bandwidth consumption due to larger HTTP headers per event.

Increased difficulty in handling network proxies and firewalls compared to traditional polling.

Which of the following are potential benefits of migrating from a Long-Polling based system to a WebSocket based system for real-time updates, assuming a high volume of frequent, small messages?

Significant reduction in total network bandwidth consumption due to smaller per-message overhead.

Simplified server-side event queuing logic, as messages can be pushed directly upon occurrence.

Improved support for handling network interruptions and re-establishing connections gracefully.

Enhanced security through automatic end-to-end encryption provided by the WebSocket protocol itself.

Which of the following are valid architectural considerations when implementing Webhooks for real-time event delivery between services?

The webhook consumer must expose a publicly accessible endpoint, requiring careful security configuration and potentially firewall adjustments.

The webhook producer needs to implement robust retry mechanisms and potentially dead-letter queues for failed deliveries.

Webhooks inherently guarantee ordered delivery of events, making them ideal for systems with strict message sequencing requirements.

Webhooks significantly increase the server-side load on the consumer due to constant incoming HTTP requests, similar to a client constantly polling.

An application needs to monitor a sensor array that sends data every 10 milliseconds. The data is critical, and any significant delay (over 50ms) in displaying it to a client is unacceptable. Which communication pattern is most suitable for this scenario, and why?

WebSockets, because they provide a persistent, full-duplex connection with minimal overhead.

Traditional Polling, because its simplicity allows for rapid implementation.

Long-Polling, because it reduces the number of empty responses, optimizing bandwidth.

Webhooks, because they are push-based and eliminate the need for client requests.

In the context of scaling a real-time application, what specific challenges does Long-Polling typically introduce on the server side that are less pronounced with traditional Polling or can be more elegantly handled with WebSockets?

Management of a large number of 'hanging' HTTP connections, potentially exhausting file descriptors or memory.

Complexity in garbage collecting stale client connections that haven't re-polled within a reasonable timeframe.

Higher computational cost per request due to the need for continuous database queries.

Increased risk of DDoS attacks specifically targeting the HTTP upgrade handshake process.

Which of the following scenarios would be best served by implementing a Webhook-based solution for event notification?

An e-commerce platform notifying a shipping service whenever a new order is placed.

A stock market ticker displaying real-time price updates to thousands of concurrent browser clients.

A multiplayer online game requiring low-latency synchronization of player positions and actions.

A mobile application periodically checking for new email messages every 30 seconds.

Polling vs. Long-Polling vs. WebSockets vs. Webhooks — Free MCQ Practice Test

Polling vs. Long-Polling vs. WebSockets vs. Webhooks — Free MCQ Practice Test | testpaper.space