How to send data to corresponding region's instance server?

Question

Let's say I have three regions(eu,us,asia) that host the same app on the respective instance. I will register only one domain name for those same apps.

When a user requests from eu , I like to send data to eu region app server and vice versa.

Eg: user -> request -> example.com (from eu) -> send data to eu app

Eg: user -> request -> example.com (from us) -> send data to us app

Eg: user -> request -> example.com (from asia) -> send data to asia app

Can I set up like that by Load Balancer or something else?

Answer 1

Yes, you can do this with OCI DNS and traffic management via geolocation traffic steering policies. The steering policy should filter or prioritize DNS answers based on a query's continent geokey.

Example of a POST /steeringPolicies request body using the ROUTE_BY_GEO template:

{
  "compartmentId": "ocid1...",
  "displayName": "Geolocations mapped to answer pools",
  "ttl": 30,
  "healthCheckMonitorId": "ocid1...",
  "template": "ROUTE_BY_GEO",
  "answers": [
    {
      "name": "US Server 1",
      "rtype": "A",
      "rdata": "192.168.0.2",
      "pool": "US"
    },
    {
      "name": "US Server 2",
      "rtype": "A",
      "rdata": "192.168.0.3",
      "pool": "US"
    },
    {
      "name": "EU Server 1",
      "rtype": "A",
      "rdata": "192.168.0.4",
      "pool": "EU"
    },
    {
      "name": "EU Server 2",
      "rtype": "A",
      "rdata": "192.168.0.5",
      "pool": "EU"
    },
    {
      "name": "rest of world 1",
      "rtype": "A",
      "rdata": "203.0.113.2",
      "pool": "Global"
    },
    {
      "name": "rest of world 2",
      "rtype": "A",
      "rdata": "203.0.113.3",
      "pool": "Global"
    }
  ],
  "rules": [
    {
      "ruleType": "FILTER",
      "defaultAnswerData": [
        {
          "answerCondition": "answer.isDisabled != true",
          "shouldKeep": true
        }
      ]
    },
    {
      "ruleType": "HEALTH"
    },
    {
      "ruleType": "PRIORITY",
      "cases": [
        {
          "caseCondition": "query.client.geoKey in (geoKey '6255149')",
          "answerData": [
            {
              "answerCondition": "answer.pool == 'US'",
              "value": 1
            },
            {
              "answerCondition": "answer.pool == 'EU'",
              "value": 2
            },
            {
              "answerCondition": "answer.pool == 'Global'",
              "value": 3
            }
          ]
        },
        {
          "caseCondition": "query.client.geokey in (geokey '6255148')",
          "answerData": [
            {
              "answerCondition": "answer.pool == 'EU'",
              "value": 1
            },
            {
              "answerCondition": "answer.pool == 'US'",
              "value": 2
            },
            {
              "answerCondition": "answer.pool == 'Global'",
              "value": 3
            }
          ]
        },
        {
          "answerData": [
            {
              "answerCondition": "answer.pool == 'Global'",
              "value": 1
            },
            {
              "answerCondition": "answer.pool == 'US'",
              "value": 2
            },
            {
              "answerCondition": "answer.pool == 'EU'",
              "value": 3
            }
          ]
        }
      ]
    },
    {
      "ruleType": "LIMIT",
      "defaultCount": 1
    }
  ]
}

-- Traffic Management Steering Policies API Guide, Create Steering Policies Using Templates