6.4 Fault Recovery Scenarios

This section describes the fault recovery procedures for various scenarios.

6.4.1 Site Failure

This is a scenario where you have cnDBTier and NEF installed on single site with automatic data replication and backup enabled. It is observed that the site has failed and there is a requirement to perform fault recovery.

Following are the assumptions:
To recover the NEF site:
  1. Uninstall NEF. For information about uninstalling NEF, see the Uninstalling NEF section.
  2. (Optional) Install Oracle Communications Cloud Native Environment. For information about installing CNE, see Oracle Communications Cloud Native Core, Cloud Native Environment Installation, Upgrade, and Fault Recovery Guide .
  3. (Optional) Install cnDBTier. For information about installing cnDBTier, see Oracle Communications Cloud Native Core, cnDBTier Installation, Upgrade, and Fault Recovery Guide.
  4. Perform cnDBTier fault recovery procedure by using the auto-data backup file. For more information about cnDBTier restore, see the "Restore Database with Backup" procedure in Oracle Communications Cloud Native Core, cnDBTier Installation, Upgrade, and Fault Recovery Guide.

    Note:

    The auto-data backup file is the one that is built from scheduled automatic backups. The cnDBTier Backup Manager service ensures auto-data backup as per the predefined configuration. For more information about cnDBTier Backup Manager Service, see Oracle Communications Cloud Native Core, cnDBTier User Guide.
  5. Install NEF using the helm charts. For more information about installing NEF, see the Installing NEF section.

Caution:

This scenario may cause loss of data.

6.4.2 NEF Migration to New Cluster

This is a scenario where you want to migrate NEF to a new cnDBTier cluster. The following resons can cause the migration:
  • cnDBTier is in healthy state, only NEF is migrated to a new cluster
  • Database failure
  • Moving NEF to a bigger cnDBTier
  • Moving NEF to a new (freshly installed) cnDBTier where upgrade is not supported

Note:

This scenario is applicable when cnDBTier is in healthy state and NEF must be migrated to a new cluster.
Assumptions
  • One of the cnDBTier is in healthy state.
  • All the prerequisites mentioned in the Prerequisites are met.

To migrate NEF:

  1. Take a backup of the oc-nef-24.2.2-custom-values.yaml file for NEF.
  2. (Optional) Install CNE cluster on new site. For information about installing CNE cluster, see Oracle Communications Cloud Native Core, Cloud Native Environment Installation, Upgrade, and Fault Recovery Guide .
  3. Install NEF using the oc-nef-24.2.2-custom-values.yaml file.

Note:

NEF does not provide export and import of the configuration data. You must run the configuration APIs on the freshly installed site to reconfigure the components and services.

6.4.3 Recovering Corrupted Configuration Database

This is a scenario where NEF configuration database has to be recovered from a corrupted database.

Assumptions
  • One of the cnDBTier is in healthy state.
  • All the prerequisites mentioned in the Prerequisites are met.

To migrate NEF:

  1. Take a backup of the oc-nef-24.2.2-custom-values.yaml file for NEF.
  2. (Optional) Install CNE cluster on new site. For information about installing CNE cluster, see Oracle Communications Cloud Native Core, Cloud Native Environment Installation, Upgrade, and Fault Recovery Guide .
  3. Install NEF using the oc-nef-24.2.2-custom-values.yaml file.

Note:

NEF does not provide export and import of the configuration database. You must run the configuration APIs on the freshly installed site to reconfigure the components and services.

6.4.4 Recovering NEF from Deployment Failure

This scenario describes how to recover NEF when its deployment corrupts.

Following are the assumptions:
  • One of the cnDBTier is in healthy state.
  • All the prerequisites mentioned in the Prerequisites are met.

To recover NEF:

  1. Uninstall NEF. For information about uninstalling NEF, see the "Uninstalling NEF" section in Oracle Communications Cloud Native Core, Network Exposure Function Installation Guide.
  2. Install NEF using the helm charts. For more information about installing NEF, see the Installing NEF section.

6.4.5 Site Failure

This section describes how to perform fault recovery when either one or all of the sites have software failure. The following are the scenarios for site failure:

Single Site Failure

A scenario where you have cnDBTier and NEF installed on two sites with automatic data replication and backup enabled. It is observed that one of the sites have failed and there is a requirement to perform fault recovery.

Following are the assumptions:
  • One of the cnDBTier is in healthy state.
  • All the prerequisites mentioned in the Prerequisites are met.

To recover the failed site:

  1. Uninstall NEF from the failed site. For information about uninstalling NEF, see the "Uninstalling NEF" section in Oracle Communications Cloud Native Core, Network Exposure Function Installation, Upgrade, and Fault Recovery Guide.
  2. Uninstall CAPIF from the failed site. For information about uninstalling CAPIF, see the "Uninstalling CAPIF" section in Oracle Communications Cloud Native Core, Network Exposure Function Installation, Upgrade, and Fault Recovery Guide.
  3. (Optional) Install CNE, in case the complete site is down. For information about installing CNE, see Oracle Communications Cloud Native Core, Cloud Native Environment Installation, Upgrade, and Fault Recovery Guide .
  4. (Optional) Install cnDBTier, in case replication is down or cnDBTier pods are not up and running. For information about installing cnDBTier, see Oracle Communications Cloud Native Core, cnDBTier Installation, Upgrade, and Fault Recovery Guide.
  5. Perform cnDBTier fault recovery procedure:
    1. Perform cnDBTier fault recovery procedure to take backup from older healthy site by following the "Create On-demand Database Backup" procedure in Oracle Communications Cloud Native Core, cnDBTier Installation, Upgrade, and Fault Recovery Guide.
    2. Restore the database to new site by following the "Restore Database with Backup" procedure in Oracle Communications Cloud Native Core, cnDBTier Installation, Upgrade, and Fault Recovery Guide .
  6. Install CAPIF and NEF instances using the respective custom values yaml files.

Complete Site Outage

This is a scenario where you have cnDBTier and NEF installed on two sites with automatic data replication and backup enabled, but both the sites have failed, and there is a requirement to perform fault recovery.

Following are the assumptions:
  • One of the cnDBTier is in healthy state.
  • All the prerequisites mentioned in the Prerequisites are met.

To recover both the sites:

  1. Uninstall NEF. For information about uninstalling NEF, see the "Uninstalling NEF" section in Oracle Communications Cloud Native Core, Network Exposure Function Installation, Upgrade, and Fault Recovery Guide .
  2. Uninstall CAPIF. For information about uninstalling CAPIF, see the Uninstalling CAPIF section.
  3. (Optional) Install Oracle Communications Cloud Native Environment. For information about installing CNE, see Oracle Communications Cloud Native Core, Cloud Native Environment Installation, Upgrade, and Fault Recovery Guide.
  4. (Optional) Install cnDBTier. For information about installing cnDBTier, see Oracle Communications Cloud Native Core, cnDBTier Installation, Upgrade, and Fault Recovery Guide .
  5. Perform cnDBTier fault recovery procedure.Use auto-data backup file for restore procedure. For more information about cnDBTier restore, see the "Restore Database with Backup" procedure in Oracle Communications Cloud Native Core, cnDBTier Installation, Upgrade, and Fault Recovery Guide .

    Note:

    The auto-data backup file is one that built from scheduled automatic backup. cnDBTier Backup Manager Service ensures auto-data backup as per the predefined configuration. For more information about cnDBTier Backup Manager Service, see Oracle Communications Cloud Native Core, cnDBTier User Guide.
  6. Install NEF using the helm charts on all the sites with site-specific custom values. For more information about installing NEF, see the Installing NEF section.

    Caution:

    There might be a data loss in this scenario.