Hello and welcome to the SAP HANA Academy. My
name is Denys van Kempen and in this
video tutorial series we'll discuss
what's new with SAP HANA SPS 12.
Topic of this video tutorial is High
Availability and disaster recovery and
to be more precise it's about system
replication and the agenda we have six
items. System parameter monitoring,
initialization of the secondary site,
alerts monitoring of the secondary site,
supported replication modes for the Tier
3, replication monitoring using SAP HANA
Cockpit and the new replication alert.
Starting with the system parameter
checker. New is that the checker can spot
differences between not only the primary
and secondary but also between the tier
3 site. The typical setup would be to
have your primary and secondary site
close to each other with, very little
latency. This allow you to set up the
systems using synchronous replication
which will guarantee there is no data
loss and then for disaster recovery
purposes you might set up a third side
in a more remote data center and this
would be your tier 3. Prior to SPS
12 this tier 3 was configured using
asynchronous replication and there was
no system parameter checking but as of
SPS 12 all replication modes are
supported and system parameter checker
occurs on all levels. The system
parameters or ini file parameters are
checked based on alerts and it's now
possible to replicate any changes to all
sites. Here we see the configuration of
the ini file checker. It’s part of the
global ini system configuration. It’s
enabled by default. Certain parameters
are excluded. Also and actually you can
add your own parameters. Default check
interval is one hour and you can
configure the ini file checker to
replicate changes to the other side this
however is switched off by default so
you will have to set it to true. Here we
see the alert that serves as the trigger
alerts 79 configuration consistency of
systems in system replication setup. Then
we have the initialization of the
secondary site prior to a SPS 12 you
would use a backup for this. Now
also possible to initialize using a
binary storage copy. This could be either
a snapshot or a file copy of the
database when it is offline. Then the
changes to the replication mode I
already mention it. Prior to SPS 12
replication from tier 2 to 3 was only
supported asynchronously and now as of
SPS 12 all modes are supported so you
can use either SYNC, SYNCMEM or
ASYNC in any combination. However if
you're going to use a different option
than ASYNC for the remote tier make
sure that latency is very low. Otherwise
it will impact the performance on the
other tiers. Now we have system
replication monitoring using the SAP HANA
Cockpit. We’ll take a look at that in a
moment. What has changed is that the
operation mode is now displayed in the
system replication tile and that a
details view has been added to the
system replication app. Additionally it's
not also possible to perform a takeover
using the SAP HANA Cockpit for offline
administration. And we see the system
replication tile of the SAP HANA
Cockpit and as you can see the operation
mode has been added. Finally we have our
new alert. Alert 94 lock replay back lock
for our system replications secondary
and it will be triggered when the
secondary site has a higher lock replay
backlog than expected. Thresholds are
configurable as it's the interval
schedule. Now let's take a look at our
live system. I'm connected here to the SAP
HANA Cockpit of system HDB. Which is
the primary site in the system
replication scenario. We have a simple
two-tier replication setup and as
mentioned the tile now mentions the
operation mode. Select the tile to open
the system replication app it will get
detailed information of both the primary
and the secondary system and a gear here
allows us to display additional columns -
reconnects, failover, save points, delta
replicas and the backlogs in megabytes
and in seconds. New is the details view
replication goes per service. So here I
will select for example the index server
on my primary site and other columns I
could just select for my overview are
now displayed here on one screen. From
here I can open the SAP HANA Cockpit for
offline administration of my secondary
system
and when I open the start stop restart
tile I have the option to perform a take
over. So I can make the secondary system
primary and the primary system secondary.
Fast-forwarding here a bit but it goes
pretty quick. When you are in idle system
of course on a full production system
will take a little longer depending on
the activity and this is something you
can use when you want to have a zero
downtime upgrade for example to update
your system from SPS 11 to 12 without
any downtime for production. For an
overview of what's new for high
availability and disaster recovery check
the release notes, the what's new guide and
how to set up and administer a monitor
system replication they have to read the
SAP administration guide. You can read or
download both guides free of charge on the
SAP help portal on help.sap.com. Thank
you for watching this SAP HANA Academy
video.