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// Copyright (C) MongoDB, Inc. 2023-present.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
package readpref_test
import (
"context"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
"go.mongodb.org/mongo-driver/mongo/readpref"
"go.mongodb.org/mongo-driver/tag"
)
// Configure a Client with a read preference that selects the nearest replica
// set member that includes tags "region: South" and "datacenter: A".
func ExampleWithTags() {
rp := readpref.Nearest(
readpref.WithTags(
"region", "South",
"datacenter", "A"))
opts := options.Client().
ApplyURI("mongodb://localhost:27017").
SetReadPreference(rp)
_, err := mongo.Connect(context.Background(), opts)
if err != nil {
panic(err)
}
}
// Configure a Client with a read preference that selects the nearest replica
// set member matching a set of tags. Try to match members in 3 stages:
//
// 1. Match replica set members that include tags "region: South" and
// "datacenter: A".
// 2. Match replica set members that includes tag "region: South".
// 3. Match any replica set member.
//
// Stage 3 is used to avoid errors when no members match the previous 2 stages.
func ExampleWithTagSets() {
tagSetList := tag.NewTagSetsFromMaps([]map[string]string{
{"region": "South", "datacenter": "A"},
{"region": "South"},
{},
})
rp := readpref.Nearest(readpref.WithTagSets(tagSetList...))
opts := options.Client().
ApplyURI("mongodb://localhost").
SetReadPreference(rp)
_, err := mongo.Connect(context.Background(), opts)
if err != nil {
panic(err)
}
}
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