# Attempt to select the secondary, except its tag doesn't match.
# Fall back to primary.
---
topology_description:
type: ReplicaSetWithPrimary
servers:
- &1
address: a:27017
avg_rtt_ms: 5
type: RSPrimary
tags:
data_center: nyc
- &2
address: b:27017
avg_rtt_ms: 5
type: RSSecondary
tags:
data_center: sf # No match.
operation: read
read_preference:
mode: SecondaryPreferred
tag_sets:
- data_center: nyc
suitable_servers:
- *1
in_latency_window:
- *1