Understand How to Enable and Optimize Keep-Alives for the NGINX Server and Its Upstreams F5N3 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   An NGINX server is experiencing high CPU usage. The team suspects that the keep-alive settings are causing too many connections to be open, leading to excessive context switching. The server handles a mix of long-lived WebSocket connections and short HTTP requests. Which change is most likely to reduce CPU usage?

   • ASet worker_processes to 1 to reduce context switching.
   • BIncrease keepalive_requests to 1000 to allow more requests per connection.
   • CIncrease keepalive_timeout to 120s to keep connections open longer.
   • DReduce keepalive_timeout to 15s to close idle connections more quickly.
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2. 2foundation · easy

   Which of the following best describes the overhead that keep-alive connections help reduce?

   • AThe network round trips required to establish a new TCP connection for each request
   • BThe disk I/O required to read static files from storage
   • CThe memory used by NGINX worker processes
   • DThe CPU cost of parsing HTTP headers
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4. 3foundation · easy

   Which directive is used inside an upstream block to configure a pool of keep-alive connections to upstream servers?

   • Aproxy_http_version
   • Bkeepalive_timeout
   • Ckeepalive
   • Dkeepalive_requests
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5. 4expert · hard

   An NGINX instance is used as a reverse proxy for a microservices architecture. There are 10 upstream services, each with 3 backend instances. The traffic pattern is spiky, with periods of high load followed by periods of near-idle. The team is concerned about the number of idle connections NGINX maintains to the backends. They want to reduce resource usage during idle periods without sacrificing performance during peak load. Which configuration approach is most appropriate?

   • ASet keepalive 128; in each upstream block to ensure enough connections are always available.
   • BSet keepalive_timeout 10s; in the http block to force NGINX to close upstream connections quickly.
   • CSet keepalive 32; in each upstream block and rely on the backend servers' own keepalive_timeout to close idle connections.
   • DSet keepalive 0; in each upstream block to disable keep-alive entirely.
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6. 5application · medium

   An NGINX server is configured as a reverse proxy. The team wants to ensure that client connections are kept alive for up to 60 seconds of inactivity, and that each client connection can serve up to 500 requests. Which configuration snippet correctly implements this?

   • Aevents { keepalive_timeout 60s; keepalive_requests 500; }
   • Bhttp { keepalive_timeout 60s; keepalive_requests 500; }
   • Cserver { keepalive_timeout 60s; keepalive_requests 500; }
   • Dupstream backend { keepalive_timeout 60s; keepalive_requests 500; }
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