Exploring new feature of HANA 2’s system replication -the active:active read-enabled, allowing read-only queries on secondary system’s tables, using the new operation mode ‘logreplay_readaccess’. Note that logreplay_readaccess does not support Dynamic Tiering The IT-Conductor monitors both the primary and secondary system.

1. Managing and Monitoring HANA 2
active:active read-enabled
System Replication
Exploring new feature of HANA2’s system replication - the active:active
read-enabled, allowing read-only queries on secondary system’s tables,
using the new operation mode ‘logreplay_readaccess’.
Note that logreplay_readaccess does not support Dynamic Tiering
The IT-Conductor monitors both the primary and secondary system.
By OZSoft Consulting for ITConductor.com
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 1

2. References
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 2
• SAP HANA Administration Guide
• How To Perform System Replication for SAP HANA
• SAP HANA International Focus Group

3. Scenario
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 3
Primary SYSTEM
OZHANA201
HANA 2.0
SystemDB and Tenant
AAA
Secondary
System
OZHANA2DR1
System
Replication

4. SR with operation mode: Logreplay_readaccess
•
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 4

5. HANA Studio
The SYSTEMDB and tenant DB of the secondary
system can now be registered in the HANA Studio,
similar to the primary system
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 5

6. Reading table on secondary system (1)
There are two ways of issuing read-only query against a table in secondary system
1. Connecting directly to the secondary system (e.g. defined in HANA Studio) and
issue the SQL call from the secondary system
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 6
Secondary System

7. Reading table on secondary system (2)
•
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 7
2. SQL call from the primary with the redirect option using HINT
If the result_lag is greater
than the acceptable delay
(nn value in the ‘hana_sr’,
nn’), query will be passed
back to the primary system

8. HANA2 Cockpit – System Resources
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 8
With logreplay_readaccess, the SYSTEMDB and tenant DB of the secondary system can
now be registered as a resource, similar to the primary system
Read on row tables from the secondary system is not supported, so information on some
tiles may not be displayed.

9. HANA Cockpit – SR Views
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 9
System Replication overview can be displayed both from primary and secondary system
SR Takeover can be done from the
secondary system view

10. HANA Cockpit – SR Overview
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 10
Click on a service to get more detail

11. HANA Cockpit – SR service detail
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 11

12. HANA Cockpit – SR Network Information
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 12

13. HANA Cockpit – Monitoring the Secondary System (1)
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 13
The secondary system can be monitored similar to the primary system

14. HANA Cockpit – Monitoring the Secondary System (2)
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 14

15. IT-Conductor – Monitoring
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 15
IT-CONDUCTOR provides monitoring of the system DB and tenant
databases, for both primary and secondary (if operation_mode =
logreplay_readaccess).
In addition to monitoring, it provides drill-down feature for further
analysis, correlating alerts, performance metrics across
applications/DB/OS, and even top SQL statements

16. IT-Conductor – Monitoring the Primary System
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 16
SYSTEM DB and tenant
DB monitored as
separate elements
Drill down (with the
triangle) to display
more information

17. IT-Conductor – Monitoring the Secondary system (1)
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 17
If operation mode is
LOGREPLAY_READACCESS
SYSTEM DB is monitored
The tenantDB is also
monitored

18. IT-Conductor – Monitoring the Secondary system (2)
Author: Terry Kempis
Editor: Linh Nguyen
ITConductor.com 18
If the operation is NOT logreplay_readaccess, the host server of the
secondary system is still monitored

19. • Any Questions?
• Contact Info:
Linh Nguyen linh.nguyen@itconductor.com
Terry Kempis terry.kempis@itconductor.com
Let
itconductor.com
@itconductor