Chapter 1. 3scale operations and scaling guide

1.1. Introduction

This document describes operations and scaling tasks of a Red Hat 3scale AMP 2.5 On-Premises installation.

1.1.1. Prerequisites

An installed and initially configured AMP On-Premises instance on a supported OpenShift version.

This document is not intended for local installations on laptops or similar end user equipment.

1.1.2. Further reading

1.2. Re-deploying APIcast

After you have deployed AMP On-Premises and your chosen APIcast deployment method, you can test and promote system changes through 3scale Admin Portal. By default, APIcast deployments on OpenShift, both built-in and on other OpenShift clusters, are configured to allow you to publish changes to your staging and production gateways through the AMP UI.

Redeploy APIcast on OpenShift:

  1. Make system changes.
  2. In the UI, deploy to staging and test.
  3. In the UI, promote to production.

By default, APIcast retrieves and publishes the promoted update once every 5 minutes.

If you are using APIcast on the Docker containerized environment or a native installation, you must configure your staging and production gateways, and configure how often your gateway retrieves published changes. After you have configured your APIcast gateways, you can redeploy APIcast through the AMP UI.

To redeploy APIcast on the Docker containerized environment or a native installations:

  1. Configure your APIcast gateway and connect it to AMP On-Premises.
  2. Make system changes.
  3. In the UI, deploy to staging and test.
  4. In the UI, promote to production.

APIcast retrieves and publishes the promoted update at the configured frequency.

1.3. APIcast Built-in Wildcard Routing

The built-in APIcast gateways that accompany your on-premise 3scale deployment support wildcard domain routing at the subdomain level. This feature allows you to name a portion of your subdomain for your production and staging gateway public base URLs. To use this feature, you must have enabled it during the 3scale installation.

Note

Ensure that you are using the OpenShift Container Platform version that supports Wildcard Routing. For information on the supported versions, see Supported Configurations.

The AMP does not provide DNS capabilities, so your specified public base URL must match the DNS configuration specified in the WILDCARD_DOMAIN parameter of the OpenShift cluster on which it was deployed.

1.3.1. Modify wildcards

Perform the following steps to modify your wildcards:

  1. Log in to your AMP.
  2. Navigate to your API gateway settings page: APIs → your API → Integration → edit APIcast configuration

  3. Modify the staging and production public base URLs with a string prefix of your choice, adhere to these requirements:

    • API endpoints must not begin with a numeric character

The following is an example of a valid wildcard for a staging gateway on the domain example.com: 

apiname-staging.example.com

More Information

For information on routing, see the OpenShift documentation.

1.4. Scaling up 3scale on-premise

1.4.1. Scaling up storage

As your APIcast deployment grows, you may need to increase the amount of storage available. How you scale up storage depends on which type of file system you are using for your persistent storage.

If you are using a network file system (NFS), you can scale up your persistent volume using the oc edit pv command: 

oc edit pv <pv_name>

If you are using any other storage method, you must scale up your persistent volume manually using one of the methods listes in the following sections.

1.4.1.1. Method 1: Backup and swap persistent volumes

  1. Back up the data on your existing persistent volume.
  2. Create and attach a target persistent volume, scaled for your new size requirements.
  3. Create a pre-bound persistent volume claim. Specify the size of your new PVC The persistent volume name using the volumeName field.
  4. Restore data from your backup onto your newly created PV.

  5. Modify your deployment configuration with the name of your new PV: 

    oc edit dc/system-app
  6. Verify your new PV is configured and working correctly.
  7. Delete your previous PVC to release its claimed resources.

1.4.1.2. Method 2: Back up and redeploy 3scale

  1. Back up the data on your existing persistent volume.
  2. Shut down your 3scale pods.
  3. Create and attach a target persistent volume, scaled for your new size requirements.
  4. Restore data from your backup onto your newly created PV.

  5. Create a pre-bound persistent volume claim. Specify:

    1. The size of your new PVC
    2. The persistent volume name using the volumeName field.
  6. Deploy your AMP.yml.
  7. Verify your new PV is configured and working correctly.
  8. Delete your previous PVC to release its claimed resources.

1.4.2. Scaling up performance

1.4.2.1. Configuring 3scale on-premise deployments

By default, 3scale deployments run one process per pod. You can increase performance by running more processes per pod. Red Hat recommends running 1-2 processes per core on each node.

Perform the following steps to add more processes to a pod:

  1. Log in to your OpenShift cluster. 

    oc login

  2. Switch to your 3scale project. 

    oc project <project_name>

  3. Set the appropriate environment variable to the desired number of processes per pod.

    1. APICAST_WORKERS for APIcast pods (Red Hat recommends to keep this environment variable unset to allow APIcast to determine the number of workers by the number of CPUs available to the APIcast pod)
    2. PUMA_WORKERS for backend pods

    3. UNICORN_WORKERS for system pods 

      oc set env dc/apicast-{production/staging} --overwrite APICAST_WORKERS=<number_of_processes>
      oc set env dc/backend-listener --overwrite PUMA_WORKERS=<number_of_processes>
      oc set env dc/system-app --overwrite UNICORN_WORKERS=<number_of_processes>

1.4.2.2. Vertical and horizontal hardware scaling

You can increase the performance of your AMP deployment on OpenShift by adding resources. You can add more compute nodes as pods to your OpenShift cluster (horizontal scaling) or you can allocate more resources to existing compute nodes (vertical scaling).

Horizontal Scaling

You can add more compute nodes as pods to your OpenShift. If the additional compute nodes match the existing nodes in your cluster, you do not have to reconfigure any environment variables.

Vertical Scaling

You can allocate more resources to existing compute nodes. If you allocate more resources, you must add additional processes to your pods to increase performance.

Note

Red Hat does not recommend mixing compute nodes of a different specification or configuration on your 3scale deployment.

1.4.2.3. Scaling up routers

As your traffic increases, you must ensure your OCP routers can adequately handle requests. If your routers are limiting the throughput of your requests, you must scale up your router nodes.

1.4.2.4. Further reading

  • Scaling tasks, adding hardware compute nodes to OpenShift
  • Adding Compute Nodes
  • Routers

1.5. Operations troubleshooting

1.5.1. Accessing your logs

Each component’s deployment configuration contains logs for access and exceptions. If you encounter issues with your deployment, check these logs for details.

Follow these steps to access logs in 3scale:

  1. Find the identifier (ID) of the pod you want logs for: 

    oc get pods

  2. Enter oc logs and the ID of your chosen pod: 

    oc logs <pod>

    The system pod has two containers, each with a separate log. To access a container’s log, specify the --container parameter with the system-provider and system-developer: 

    oc logs <pod> --container=system-provider
oc logs <pod> --container=system-developer

1.5.2. Checking job queues

Job Queues contain logs of information sent from the system-sidekiq pods. Use these logs to check if your cluster is processing data. You can query the logs using the OpenShift CLI: 

oc get jobs
oc logs <job>

1.5.3. Preventing monotonic growth

To prevent monotonic growth, 3scale schedules by default, automatic purging of the following tables:

  • user_sessions - clean up is triggered once a week, deletes records older than two weeks.
  • audits - clean up is triggered once a day, deletes records older than three months.
  • log_entries - clean up triggered once a day, deletes records older than six months.
  • event_store_events - clean up is triggered once a week, deletes records older than a week.

With the exception of the above listed tables, the alerts table requires manual purging by the database administrator.

Database typeSQL command

MySQL 

DELETE FROM alerts WHERE timestamp < NOW() - INTERVAL 14 DAY;

PostgreSQL 

DELETE FROM alerts WHERE timestamp < NOW() - INTERVAL '14 day';

Oracle 

DELETE FROM alerts WHERE timestamp <= TRUNC(SYSDATE) - 14;

For other tables not specified in this section, the database administrator must manually clean the tables that the system does not automatically purge.