Cross-region Redundancy with OCI DRG for AI Workloads

Question

Pulumi · Accepted Answer

To ensure cross-region redundancy for AI workloads in Oracle Cloud Infrastructure (OCI), we can leverage the OCI Dynamic Routing Gateway (DRG), which allows us to manage and route network traffic across different VCNs (Virtual Cloud Networks) and regions. The DRG provides a virtual router that can be attached to multiple VCNs across regions, enabling us to create a redundant network topology necessary for high-availability scenarios, such as running AI workloads that require constant uptime and low-latency access.

In this program, we are going to set up redundant infrastructure using several resources provided by OCI:

1. `oci.Core.Drg`: This resource represents the DRG itself, a virtual router that provides a path for private network traffic between your VCN and on-premises network.
2. `oci.Core.DrgAttachment`: This resource represents the attachment between a DRG and a VCN. It allows the DRG to send and receive traffic to and from the attached VCN.
3. `oci.Core.DrgRouteTable`: Through DRG Route Tables, we have advanced routing scenarios. It allows us to define routing rules to direct traffic from DRG attachments.
4. `oci.Core.DrgRouteDistribution`: DRG Route Distributions allow for the collection of route rules in a single entity that can be attached to a DRG.

For AI workloads, specifically, having cross-region redundancy ensures if there's an issue in one region, your AI applications can still run unaffected in another region, providing business continuity.

Now let's write the Python program using Pulumi to create this infrastructure.

```python
import pulumi
import pulumi_oci as oci

# Replace these values with your specific information
compartment_id = 'your_compartment_id'

# Creating a Dynamic Routing Gateway for cross-region redundancy
drg = oci.core.Drg("aiWorkloadsDrg",
    compartment_id=compartment_id,
    display_name="AI-Workloads-DRG",
    freeform_tags={
        'Name': 'AI-Workloads-DRG'
    }
)

# Creating DRG attachments to VCNs in different regions would go here.
# For example, if we had VCNs with IDs 'vcn_id1' and 'vcn_id2' in two different regions:
# drg_attachment1 = oci.core.DrgAttachment("aiWorkloadsDrgAttachmentOne",
#     compartment_id=compartment_id,
#     drg_id=drg.id,
#     vcn_id='vcn_id1',
#     display_name="AI-Workloads-DRG-Attachment-1"
# )
#
# drg_attachment2 = oci.core.DrgAttachment("aiWorkloadsDrgAttachmentTwo",
#     compartment_id=compartment_id,
#     drg_id=drg.id,
#     vcn_id='vcn_id2',
#     display_name="AI-Workloads-DRG-Attachment-2"
# )

# Creating a DRG Route Table to manage the network traffic through DRG
drg_route_table = oci.core.DrgRouteTable("aiWorkloadsDrgRouteTable",
    compartment_id=compartment_id,
    drg_id=drg.id,
    display_name="AI-Workloads-DRG-Route-Table"
)

# Creating a DRG Route Distribution to manage route rules.
# This is more of an advanced setting that would be used to define specific
# traffic management rules amongst various DRG attachments.
drg_route_distribution = oci.core.DrgRouteDistribution("aiWorkloadsDrgRouteDistribution",
    compartment_id=compartment_id,
    drg_id=drg.id,
    display_name="AI-Workloads-Distribution",
    distribution_type="IMPORT"
)

# Exporting the URN of the DRG to be used in other resources if needed
pulumi.export('drg_id', drg.id)
```

In the above program:

- We created a DRG (`aiWorkloadsDrg`) which acts as a virtual router to manage network traffic for AI workloads.
- We should then create attachments using `oci.Core.DrgAttachment` for the DRGs to specific VCNs (commented out because specific VCN IDs are needed to attach; replace `'vcn_id1'` and `'vcn_id2'` with your actual VCN IDs).
- We established a DRG route table (`aiWorkloadsDrgRouteTable`) which controls how traffic is routed from the DRG to attached VCNs or networks.
- We initialized a DRG route distribution (`aiWorkloadsDrgRouteDistribution`) and set it to `IMPORT` to define how routes are imported into the DRG routing table.

You would need to create actual VCNs and then use their IDs in the commented sections for the attachments.

By setting up this configuration, you ensure that traffic between your on-premises network and VCNs in OCI is appropriately routed and that redundancy is maintained across regions to support your AI workloads reliably. This provides both scalability and high availability, which are critical for maintaining an AI environment that consistently performs well.