An Azure data analytics service for real-time analysis on large volumes of data streaming from sources including applications, websites, and internet of things devices.
For a Db2 11.5 HADR environment where only log files need to be replicated from on-premises to Azure for DR (without copying full database data), the recommended pattern is to base the design on Db2 HADR log shipping plus a shared or centrally accessible archive location.
Key points and recommended approach:
- Use Db2 HADR as the core DR mechanism
- Db2 HADR already replicates changes from the primary to the standby using transaction logs.
- The primary database is the only one that performs log archiving; when roles change, the new primary becomes responsible for log archiving.
- Ensure the Azure DR node is configured as an HADR standby so it can continuously receive and apply logs.
- Configure log archiving with a shared, highly available target
- Configure both primary (on-prem) and standby (Azure DR) databases to have automatic log retrieval capability from all log archive locations.
- Both primary and standby must be able to retrieve log archive files from any archive location that either instance might use.
- Recommended: use a common, highly available NFS share (or GlusterFS / Azure NetApp Files, depending on OS and design) as the archive target for logs. This allows:
- Primary to archive logs to the shared location.
- Standby in Azure to automatically retrieve only the required log files without copying full data files.
- Avoid duplicating archives and manage multiple archive locations
- If multiple log archive locations are configured, logs might be archived twice.
- When HADR roles change (planned or failover), the new primary will start archiving logs. If the old primary used a different archive path, archived logs might need to be manually copied from the old primary’s archive location to the active log location of the new primary.
- To minimize manual work, standardize on a shared archive location accessible from both on-prem and Azure.
- Storage options for the shared log archive
- For RHEL-based deployments, recommended options include:
- A highly available NFS share.
- GlusterFS cluster on Azure VMs.
- Azure NetApp Files NFS volumes.
- These options provide a central place where only log files are written and from which the Azure DR standby can read, without moving the database data files.
- For RHEL-based deployments, recommended options include:
- High-level implementation steps
- Ensure existing on-prem Db2 HADR is healthy and synchronized.
- Deploy the Azure DR VM(s) and configure Db2 as an HADR standby instance.
- Provision a highly available NFS/GlusterFS/Azure NetApp Files share that is reachable from both on-prem and Azure (via VPN/ExpressRoute or similar connectivity).
- Configure Db2 log archiving on the primary to write archive logs to this shared location.
- Configure the standby in Azure to automatically retrieve archived logs from the same shared location.
- Test:
- Normal log shipping and apply on the Azure standby.
- Role change/failover and confirm that the new primary continues archiving to a location accessible by the other node.
This design satisfies the requirement to “update latest log files only without DB data” by using HADR plus a shared archive location for transaction logs, while keeping database data files local to each site.
References:
- High availability of IBM Db2 LUW on Azure VMs on Red Hat Enterprise Linux Server
- High availability of IBM Db2 LUW on Azure VMs on Red Hat Enterprise Linux Server – Configure log archiving for HADR setup
- High availability of IBM Db2 LUW on Azure VMs on SUSE Linux Enterprise Server with Pacemaker
- High availability of IBM Db2 LUW on Azure VMs on SUSE Linux Enterprise Server with Pacemaker – Configure log archiving for HADR setup
- IBM Db2 Azure Virtual Machines DBMS deployment for SAP workload