Challenge 1: A Weighted Upstream Pool — Solution Walkthrough

The configuration:

  upstream api_pool {
      server 10.0.0.21:8080;
      server 10.0.0.22:8080;
      server 10.0.0.23:8080 weight=2;
  }

Why this works:

The two servers with no weight parameter default to weight=1 each,
while the third server's weight=2 gives it a proportional share of
traffic twice as large as either of the other two — per this
chapter's own weight explanation, distribution is proportional to
each server's own weight value relative to the others in the same
pool, not an absolute traffic count.

WHY THIS WORKS AS AN ANSWER
------------------------------
This exercise is a direct, hands-on application of this chapter's own
weight parameter to a new three-server pool, correctly applying the
default weight of 1 to the unweighted servers rather than needing to
write weight=1 explicitly on every line.