The SAP Landscape Management supports several SAP HANA specific operations.
SAP HANA system replication is a mechanism for ensuring the high availability of your SAP HANA system. When using the SAP HANA system replication, the continuous replication of data from a primary to a secondary system, including in-memory loading, and system replication facilitates rapid failover in the event of a disaster and productive operations can be resumed with minimal downtime. SAP HANA system replication is a prerequisite for SAP HANA operations like near-Zero Downtime Maintenance (nZDM) or Takeovers.
You can copy an original system to create an SAP HANA system replication tier for system replication. When doing this ensure your source system is enabled for configuration of system replication. Choose Configuration → Systems → [Choose your source system] → Edit.
To start the SAP HANA system replication configuration process call choose Provisioning → System and AS. Choose the system on the left side of the screen and choose Configure System Replication.
A roadmap appears to guide you through the process of SAP HANA System Replication configuration.
The figures and the animation show an outdated UI for entire workflow. The UI is now available in SAP UI5.
Available under Provisioning → Systems (tab) → Create System Replication.
Sync and Operation Modes in Replication
SAP HANA System Replication – Possible Sync Modes in Replication
The primary system commits the transaction after it receives a reply that the log was received by the secondary system, but before it has been persisted.
The primary system does not commit a transaction until it receives confirmation that the log has been persisted in the secondary system.
The primary system sends redo log buffers to the secondary system asynchronously. The primary system commits a transaction when it has been written to the log file of the primary system and sent to the secondary system through the network.
SAP HANA System Replication — Possible Operation Modes in Replication
This mode establishes a system replication where occasionally (by default every 10 minutes) a delta data shipping takes place in addition to the continuous log shipping. The shipped redo log is not replayed on the secondary site.
This mode does not require a delta data shipping anymore. Additionally, the shipped redo log is continuously replayed on the secondary site.
|logreplay_readaccess||This mode is required for replication to an Active/Active (read enabled) secondary system. It is similar to the log replay operation mode regarding the continuous log shipping, the redo log replay on the secondary system, as well as the required initial full data shipping and the takeover.|
You can specify the target hosts for the new system. To specify the host, choose the type of target host. To prepare and start the target system on an existing host choose Use Existing Host. If you have a configured virtualization manager and want to provision a new host of your system is locally installed on a virtual host, choose Provision New Host and navigate through the workflow.
SAP Landscape Management is able to configure and create virtual host names and physical host names for newly provisioned virtual machines. If you do not want Landscape Management to create host names, you have to create these host names up-front on your name server. Define the combination of virtual host—name and instance. To assign an IP address automatically by using the range of IPs you specified when configuring the landscape, choose Auto IP Address. You can choose a previously created network.
You can manage the cloning of volumes of the source system to the target system within the Storage step. It is recommended to do a full clone of the volumes for the creation of a system replication. This step is only applicable if you use storage based provisioning.
You can change the preselected release configuration for each instance, if required. For some database release configurations, you must specify the database administrator and manager credentials of the source system. To see if your system is ready for system copy, choose Execute Prerequisite Checker.
SAP HANA System Replication – Summary
Summary shows you selection. You can execute the operation by choosing Configure System Replication.
SAP Landscape Management creates a new SAP HANA database and configures the SAP HANA system replication. You are forwarded to the monitoring screen.
If you already have two SAP HANA databases available that meet the SAP HANA system replication, you can execute the procedure described in the figure, SAP HANA System Replication - Configuring the Primary System. Choose Operations & Maintenance → Operations → Instances and choose HANA System Replication → Enables System Replication for the primary system, and enter a site name for the system.
To set up the secondary system for system replication, you must configure and register it with the primary system. To do this, the secondary side must have the status Not Running. Choose Operations & Maintenance → Operations → Instances and choose HANA System Replication → Register Secondary for System Replication.
The figure shows the field to enter the secondary configuration data.
These are the possible entries, which you must provide from the following table:
Secondary System Configuration Data
|Mode||Choose the replication log mode.|
|Operation Mode||Choose the replication operation mode.|
|Remote Host||Enter the name of the primary host that the secondary system registers with.|
|Site Name||Enter an alias to represents the secondary site.|
De-listing the Secondary Tier
Start your secondary sites as the last step.
You can de-list a secondary site form its source, for example to disable system replication. To do this, the secondary side must have the status Not Running, while the primary side needs to have the status Running. Choose Operations & Maintenance → Operations → Instances and choose the SAP HANA secondary side of the system where you want to disable the SAP HANA system replication.
You can disable system replication on the primary system or on the tier 2 secondary system (the source system). To do this choose Operations & Maintenance → Operations → Instances and choose the SAP HANA primary side of the system where you want to disable SAP HANA system replication.