Kong: an Upstream is a named group of Targets for load balancing

A Service can point at one host, or at an Upstream that spreads traffic over many Targets with weights and health checks.

Code

curl -X POST http://localhost:8001/upstreams --data name=billing-upstream

curl -X POST http://localhost:8001/upstreams/billing-upstream/targets \
  --data target=10.0.1.11:8080 --data weight=100
curl -X POST http://localhost:8001/upstreams/billing-upstream/targets \
  --data target=10.0.1.12:8080 --data weight=100

# point the service at the upstream by NAME
curl -X PATCH http://localhost:8001/services/billing \
  --data host=billing-upstream

Output

# The service's `host` is resolved as an upstream name first, and as DNS
# only if no upstream matches. That is the whole wiring.
#
# weight=0 drains a target without deleting it - the clean way to take a
# node out for a deploy.

curl -s localhost:8001/upstreams/billing-upstream/targets | jq '.data[].target'

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Published 2026-08-25