Hello and welcome to the SAP HANA Academy.
My name is Denys van Kempen
and in this video tutorial series will discuss SAP HANA SPS 12 installation and update.
The topic of this video tutorial is installation concepts.
An SAP HANA system is composed of three main components: host, system and instance.
The host is the operating environment in which the SAP HANA database runs.
It provides the resources and services: CPU, memory, network and operating system
that the HANA database requires. Storage does not have to be on the local host.
For multiple host systems a type of shared storage is required.
An SAP HANA instance is a collection of HANA system components that are installed on a host.
A typical HANA instance will have a process for the database engine,
a process for the built-in application server, and a couple of more
processes and together they form an instance.
On a single host system, typically, there's only one single instance.
A multiple host system will have two, or more, instances distributed across multiple hosts.
Every system has an instance number: a two digit identifier,
and in a multiple host system each instance must have the same instance number.
One or more instances with the same number are referred to as a system.
If a system has more than one instance, they must be running on different hosts as a multiple hosts system.
You cannot have multiple instances of the same system on a single host
but you can have multiple instances of different systems on a single host.
It's not very common and there are support restrictions
but conceptually this is OK.
Every system has a unique SAP system ID, SID, system identifier: three characters
starting with a letter, A01, DB1, a number is not required,
ABC is fine, with some restrictions:
SAP is not an option, nor is IBM.
You configure an SAP HANA system either as a single host or multiple hosts system
with the HANA database lifecycle manager tool hdblcm,
either when installing or later when needed.
Creating a multiple hosts or distributed system from a single system is actually very easy
You just add a host.
If you need more resources, you can add more hosts and if you need less, you can
just as easily remove hosts.
The next illustration shows the file system for a single host installation.
We see the system configuration
with instance number 01, SID DB1, and host hana1.
HANA is installed in the path /usr (Unix System Resources)
/SAP and then the SID.
This is the default location for the local install.
All host-specific files will be stored here:
trace files, log files, for example.
Then the database data and log files will be stored on the shared storage path, even for a single host.
The default is /hana/shared and then the SID for all the binaries (the program files)
and /hana/data for the database data files and /log for the database log files.
If we then take a look at a distribution system,
not much changes: we're just adding hosts. So this is a very flexible architecture
and that's why it's easy to add or remove hosts.
Next, we have the deployment types for the on-premise version.
You could also use SAP HANA in cloud-based scenarios, of course, but that's not the topic of this video.
At the bottom, you can see if the deployment type is approved for production.
To the left, the most basic type: dedicated. Application 1 is hosted by system 1,
part of a single schema (a container of tables, indexes, procedures, functions and so on)
all in a single database, and the database runs on a single host or multiple hosts
supported by shared storage because that's not relevant here and it's the same for
application 2 and both are totally isolated from each other at all levels.
MDC (multi-tenancy or multi-tenant database containers)
Deployment type was introduced with SAP HANA SPS09.
Provides an alternative for virtualized deployments and the MCOS deployment type
(Multiple Components in One System),
which only in some scenarios are supported in production.
In an MDC environment, two or more applications
share an SAP HANA instance and database.
So, both from a resource perspective
(CPU, memory, compute power)
and from a database administration perspective
(monitoring, backups, etc.)
it's a big advantage.
Resources are shared yet the applications are completely isolated from one another.
So, from an application management point of view (security, backups etc.)
these are independent entities.
MCOD (Multiple Components in One Database):
multiple applications share a single SAP HANA instance.
In other words, resources are shared, so a lower TCO (total cost of ownership)
but there is no isolation at the application level.
There is a single backup of the system and there is resource sharing.
So, for a single company this may be acceptable.
However, some restrictions apply.
SAP supports deploying and running multiple applications on a single SAP HANA
production database only for certain packaged applications
listed on a whitelist; we will take a look at that in a moment.
Then we have virtualised.
HANA systems can run on virtual machines with some restrictions.
These are specified also in SAP notes.
Finally, Multiple Components on One System (MCOS).
Here we have one or more HANA installations on a single host.
Again, supported in some scenarios.
Basically, this means that you install SAP HANA one, or more times, on a single computer.
Say, if you want to test different HANA versions.
If the host, the computer, is powerful enough - enough memory, CPU - this will work just fine.
Just as in the MCOD deployment model,
you share storage and the operating system
The difference is that you have a different HANA installation
So this could be a different release but not necessarily.
You have shared compute resources but not shared database administration resources.
We have two HANA instances, so we have two separate systems to monitor, to backup, etc.
Only in the MDC deployment model we find both combined:
shared compute resources and shared database administration.
There are a couple of SAP notes on these topics.
We have 1681092: Multiple SAP HANA databases on a single SAP HANA system (MCOS):
describes support status and restrictions.
SAP note 1661202: support multiple applications on one HANA database (MCOD):
This has the whitelist have supported combinations.
and note 1788665: SAP HANA support for virtualized environments,
which lists all supported hypervisors.
So much for HANA server installation concepts.
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Thank you for watching this SAP HANA Academy video.