Hello and welcome to the SAP HANA Academy.
The topic of this video tutorial series is SAP HANA 2.0 SPS 02 - What’s New? and in
this video we will discuss high availability and the SAP HANA cockpit.
Hi, I am Denys van Kempen.
We have seen that for the topic areas of platform and application lifecycle management, security,
database backup and recovery, to name a few, there have not been many radical changes.
It is a minor release, SPS 02: enhancements and improvements.
For high availability, this is more or less the same.
For example, should you have activated the new Active/Active (read enabled) system replication
operation mode in HANA 2.0, SPS 00 or 01, and attempted to query a row store table,
HANA would return you the message ‘feature not enabled’.
Only column store tables, initially, supported read access on the secondary node.
This restriction has been lifted, all row store table types are now supported.
For the details, see note 2391079,
Access restrictions in Active/Active (read enabled) system setup.
Several restrictions have been lifted, as well, for the Dynamic Tiering option.
Most importantly, as of SPS 02, you can enable the system replication Active/Active (read
enabled) mode when Dynamic Tiering is active.
Previously, this was not possible.
It was either, or.
There is a note, 2447994, which has a document attached.
SAP HANA System Replication on Systems with Dynamic Tiering.
Here we find it on page 10.
But there are about 20 pages.
So if you intend to use dynamic tiering together with system replication, make sure to take note.
You might also want to check out note 2488106.
Also lists some additional notes for Dynamic Tiering with system replication.
Support for multi-tenant systems has been enhanced, as well.
You can now copy (or move) a tenant database both to and from a primary system that has
been configured for system replication.
The process has not changed.
It is documented in the SAP HANA Tenant Database Operations Guide.
If you are not familiar with the process, you might want to read up about it here.
There are quite a number of steps.
Most have to do with securing the network configuration as data must be replicated via
a secure SSL/TLS network connection, by default.
For training and test environments, you can disable this, however.
Makes it a bit easier to setup.
Some parts you can do in HANA cockpit.
For others, you will have to enter SQL.
Here we have a sample.
After you have setup security, you create your tenant with statement
CREATE DATABASE AS REPLICA OF database name AT hostname and port of the name server.
Next, you query the view M_DATABASE_REPLICAS on REPLICATION_STATUS.
Initially, this will be ‘Initializing’ but after some time the status will be ‘active’.
Then, you can finalize replication with statement ALTER DATABASE database name FINALIZE REPLICA;
Now, as mentioned, tenant database copy is not new but the supported use cases have been
enhanced and we now also find the replication status ‘tenantcopy' displayed in HANA cockpit.
Concerning HANA cockpit, this is not the only enhancement.
What’s also new is the display of the Secondary Read Access in the header here of the System
Replication Overview page together with the Network Security Setting, here, default.
Network Security Settings has its own tab now and here we can view the configuration
of the different related parameters.
The section above, Network Speed Check, was introduced in the previous release but what's
new is that we now also have a direct link to this page on the Overview page.
Just a couple of improvements to the HANA cockpit for system replication.
Then, we also have a new alert, alert 104, ‘Log shipping backlog for system replication secondary’,
which will alert you when there are network issues and the primary has trouble
connecting to the secondary.
You really want the secondary to be in synch with the primary, so, a log shipping backlog
is a bad thing.
Should a takeover have to take place with a large backlog and the primary is no longer available,
data loss will occur, so you want to be alerted about this.
Finally, we have a new hook, a new HA/DR provider - high availability, disaster recovery -
as the API is fully named.
The Python script HADRDummy.py lists them all, as sample.
SPS 02 adds the srReadAccessInitialized() provider, which shows on the primary system
when the SQL ports are open on the secondary system;
similar to the header of the HANA cockpit System Replication Overview page we just discussed.
Well, that pretty much wraps it up.
A new hook, a new alert, UI enhancements in cockpit
and support enhancements for Dynamic Tiering and multi-tenant database container systems.
For more information with links to the documentation and other resources, please check out my blog on this topic.
You can find more video tutorials on our YouTube channel.
If you would like to be informed about new video tutorials, please subscribe to our channel.
You can connect with us on LinkedIn or follow us on Twitter, as well for updates.
And we also have a page on Facebook and Google+.
If you are watching this video on YouTube, do not hesitate to leave your comments to
the video page and, if you like, give us your vote on his video.
Thank you for watching.