Construct a Sequence Diagram That Includes API Calls 350-901 Practice Questions (Page 3)

Questions 11–15

1. 11expert · medium

   A developer is documenting a REST API that returns a 202 Accepted for asynchronous processing. The client then polls a status endpoint until it receives a 200 OK. How should the polling interaction be represented in a sequence diagram?

   • AA 'par' fragment to show the polling requests happening in parallel
   • BAn 'alt' fragment with one operand for each poll attempt
   • CA 'loop' combined fragment containing the client's status request and the server's response
   • DA single request-response pair, since the final 200 OK is the only important response
   Reveal Solution Discussion Select an answer first
2. 12foundation · easy

   A developer is constructing a sequence diagram for an API workflow where a client calls an authentication service, then calls a data service using the returned token. Which lifelines should be included in the diagram?

   • AClient, Authentication Service, and Data Service
   • BClient, Authentication Service, Data Service, and Database
   • CAuthentication Service and Data Service only
   • DClient and Data Service only
   Reveal Solution Discussion Select an answer first
4. 13application · easy

   A team is reviewing a sequence diagram that models a user logging into a system. The diagram includes a lifeline for the user, the web server, and the database. The user sends credentials to the web server, which queries the database. After the database returns a result, the web server sends a session token back to the user. Which lifeline represents an external actor in this diagram?

   • AThe database lifeline
   • BAll three lifelines are actors
   • CThe web server lifeline
   • DThe user lifeline
   Reveal Solution Discussion Select an answer first
5. 14expert · medium

   A team is designing a sequence diagram for a distributed transaction. The client calls Service A. Service A calls Service B, which then calls Service C. Service C returns a response to Service B, and Service B returns a response to Service A. Finally, Service A returns a response to the client. The team wants to show that Service B and Service C are on different hosts. How should this be represented?

   • AUse a single lifeline for Service B and Service C, with a note indicating different hosts
   • BUse separate lifelines for Service B and Service C, each with its own activation bar
   • CUse a combined fragment labeled 'par' to show Service B and Service C executing in parallel
   • DUse a state invariant on Service B to indicate it is on a different host
   Reveal Solution Discussion Select an answer first
6. 15foundation · easy

   In a UML sequence diagram, which notation is used to represent a synchronous message, such as a blocking HTTP request?

   • AA filled solid arrowhead (solid line)
   • BA solid line with an 'X' at the end
   • CAn open arrowhead (solid line)
   • DA dashed line with an open arrowhead
   Reveal Solution Discussion Select an answer first