Server architecture for SAP HANA XS Advanced Runtime Platform

 SAP HANA extended application services, advanced model (XS advanced for short) provides a comprehensive platform for the development and execution of micro-service oriented applications, taking advantage of SAP HANA's in-memory architecture and parallel execution capabilities.

About SAP HANA XS Advanced

SAP HANA XS advanced offers a rich set of embedded services that enable end-to-end support for web-based applications including lightweight web servers, persistency services, and a configurable identity provider. Furthermore, the platform supports polyglot application development with a core set of pre-deployed runtimes that are accepted as industry standards, for example, node.js or JavaEE.

Although the built-in runtimes come with first-class development and monitoring support, the platform has an open architecture that allows you to add custom runtimes. This high flexibility makes it essential that you put a strong focus on security concepts, not only when configuring and setting up the infrastructure, but also throughout operating the system.

Architecture Overview

The basic system architecture has a classic 3-tier approach, we can see in below diagram 

There is a distinction between the overall SAP HANA system and the SAP HANA XS advanced application server. The SAP HANA system refers to the entire SAP HANA platform as part of the integrated solution. All services of the SAP HANA system share the same system identifiers (that is, instance number and SID) and are controlled by the hdbdaemon service.

The third tier, represented by an SAP HANA database, provides persistency services, that is, data storage. In contrast, the application server components in the middle tier are responsible for deploying, running, and monitoring the applications. Most security-related features such as authentication, authorization, and auditing are primarily enforced in this layer. End users interact on the client layer with system or business users that are authenticated by an identity provider (IdP), which is SAP HANA user management by default. However, both the server components and the applications themselves access the SAP HANA database only through technical database users that the platform generates implicitly. Direct access to the database is only intended for database administration and monitoring purposes.

The following diagram provides a more detailed overview of the technical system landscape of the XS advanced application server. All relevant components and storages used by the application server layer are highlighted with a gray background.

Technical System Landscape of XS Advanced Application Server

The XS advanced application server relies on the following SAP HANA services contributing to the integrated platform solution:

1. xscontroller (Controller, FileSystem Broker, Platform Router)
2. xsexecagent (Execution Agent)
3. xsuaaserver (UAA, UAA Broker and SAP HANA Service Broker)

Thanks 

Rupesh Chavan

HANA Administration Guide

Administration of Tenant Databases in SAP HANA System

 In SAP HANA systems, there are two types of administration tasks: those performed at the system level and those performed at the database level.

System Versus Database Administration

Tenant database systems have two levels of administration.

Some administration tasks are performed in the system database and apply globally to the system and all its databases. They include for example:

• Starting and stopping the whole system

• Monitoring the system

• Configuring parameters in configuration (*ini) files at system level

• Setting up and configuring tenant databases, for example:

• Creating and dropping tenant databases

• Disabling features on tenant databases

• Configuring system- and database-specific parameters in configuration (*ini) files

• Scaling out tenant databases by adding services

• Backing up tenant databases

• Recovering tenant databases

• Monitoring the database

• Provisioning database users

• Creating and deleting schemas, tables, and indexes in the database

• Backing up the database

• Configuring database-specific parameters in configuration (*ini) files

Some administration tasks are performed in the tenant database and apply only to that database. They include for example:

you can refer SAP HANA administration guide to get more detailed information about Tenant database administration. 

Thanks 

Rupesh Chavan

SAP HANA System Architecture #Hana

 An SAP HANA system includes multiple isolated databases and may consist of one host or several hosts.
An SAP HANA system is identified by a single system ID (SID) and contains one or more tenant databases and one System DB. System DB/Tenant databases are identified by a SID and a database name. We can identify differences between System DB and tenant database on the basis of tasks performed at the database level. We can connect respective databases from HANA Studio, SAP HANA Cockpit and DBACOCKPIT from an administration standpoint. 
The SAP HANA XS advanced application server is a layer on top of SAP HANA that provides the platform for running SAP HANA-based Web applications. It is an integral part of the SAP HANA system.
A HANA system may consist of one host or a cluster of multiple hosts. which is called a "multiple-host, distributed system, or scale-out system and supports scalability and availability" 

 Server Architecture 

An SAP HANA database consists of multiple servers/Services, for example, a name server, index server, preprocessor server, and so on. The most important Server is the index server. It contains the actual data stores and the engines for processing the data and runs in every tenant database.

Only the system database runs the name server. The name server contains landscape information about the system as a whole, including which tenant databases exist. It also provides index server functionality for the system database. The name server does not own information about the location of tables and table partitions in tenant databases. Database-related information is stored in the relevant tenant database catalogue.
Tenant databases require only their own index server. Servers that do not persist data, such as the compile server and the preprocessor server, run on the system database and serve all databases.

• ·        Set of database users

• ·        Database catalog

• ·        Repository

• ·        Persistence

• ·        Backups

• ·        Traces and logs

If the SAP HANA XS classic server is available, it runs embedded in the (master) index server of the tenant database by default.

Tenant Databases

SAP HANA supports multiple isolated databases in a single SAP HANA system. These are referred to as tenant databases.

A system always has exactly one system database, used for central system administration, and any number of tenant databases (including zero).

All the databases share the same installation of database system software, the same computing resources, and the same system administration. However, each database is self-contained and fully isolated with its own:

Although database objects such as schemas, tables, views, procedures, and so on are local to the database, cross-database SELECT queries are possible. This supports cross-application reporting. 

The System Database

The system database is created during either installation or conversion from a single-container system to a tenant database system. The system database contains information about the system as a whole, as well as all its tenant databases. It is used for central system administration.

A system has exactly one system database. It contains the data and users for system administration. System administration tools, such as the SAP HANA cockpit, can connect to this database. The system database stores overall system landscape information, including knowledge of the tenant databases that exist in the system. However, it doesn't own database-related topology information, that is, information about the location of tables and table partitions in databases. Database-related topology information is stored in the relevant tenant database catalog.

Administration tasks performed in the system database apply to the system as a whole and all of its databases (for example, system-level configuration settings), or can target specific tenant databases (for example, backup of a tenant database). For more information, see Administration of Tenant Databases.

Things to Remember About the System Database

• The system database does not have the same functionality as a tenant database.

• The system database is not a database with full SQL support.

• The system database cannot be distributed across multiple hosts, in other words, scale-out is not possible.

• If you need a full-featured SAP HANA database, you always have to create at least one tenant database.

• The system database does not support Application Function Libraries (AFL) and SAP liveCache applications.

• Cross-database access between the system database and a tenant database is not possible. The system database can show monitoring data from tenant databases (views in the schema SYS_DATABASES) but can never show actual content from tenant databases.

• The system database cannot be copied or moved to another host.

• SAP HANA options can only run in tenant databases.

• Tenant-specific configurations cannot be set in the system database. Only global settings are allowed.

• Features can only be restricted or disabled at a high level for tenant databases.

Thanks

Rupesh Chavan

 

 

How to start HANA Systems in SAP HANA Studio ?

Start a System

To initiate or start an SAP HANA system, we can utilize the SAP HANA studio. This will start all tenant databases except for those that were manually stopped.

Prerequisites

To continue with the process, it's important to have the login information for the operating system user, especially the <sid>adm user that was created during the HANA database installation. Please make sure you have this information before proceeding.

Procedure

1. In the Systems view, right-click the system you want to start and choose Configuration and Monitoring  Start System..

Note:  

Execute the start command from the system database. The Start System... command is not available from tenant databases. For more information about how to stop an individual tenant database, see Stop and Start a Tenant Database.

1. Enter the user name and password of the operating system administrator that was created when the system was installed (that is, <sid>adm user).

  3: The Administration editor opens in diagnosis mode and the database services start one by one. When all services have started, the system appears as operational () in the Systems view.

  4:  All tenant databases are started. However, if a tenant database was previously stopped individually, it is not started with the system. For more information about how to stop an individual tenant database, see Stop and Start a Tenant Database.

Thanks 

Rupesh Chavan

HANA Studio Guide 

How to add an SAP HANA System in HANA Studio ?

Prerequisites

• The relevant ports in your firewall are open.
• If you want to secure communication between the SAP HANA server and the SAP HANA studio using the Secure Sockets Layer (SSL) protocol, you have configured the server for SSL and imported the trust store file that contains the server root certificate into either the Java keystore or your user keystore on the client.
• You must have a database user, or the necessary infrastructure for Kerberos-based user authentication must be in place.

Procedure

1. From the Systems view toolbar, choose  (Add System...).
   The System wizard opens.
2. Enter the required system information:
• System connection properties (required)
  • Host name
  • Instance
  • Mode

  
  

System Connection Properties

To connect to an SAP HANA system or database in the SAP HANA studio, you must specify its connection properties (host, instance, and mode).

Property	Description
Host name	Fully qualified domain name (FQDN) of the host on which the system is installed Multi-host system If you are adding a multi-host system, specify the master host. You do not have to enter all host names explicitly as they are determined automatically. If the master host becomes unavailable, the connection is automatically established through one of the other hosts. Hosts that are added to the system later are also detected automatically. Tip Once you have finished adding the system, you can see all available hosts in the system properties. Right-click the system in the Systems view and choose Properties. All hosts are listed on the Hosts Used to Connect tab of the Database User Logon page. Note The host name of the server that hosts the database must be accessible from the client on which the SAP HANA studio is running, even if you add the system using its IP address. Tenant databases If you are adding a tenant database in a tenant database system, specify the FQDN of the system host.
Instance	Instance number of the system
Mode	Whether the system you are connecting to is a single-container system or multiple-container system If you are connecting to a system with tenant databases, then you must further specify the specific database that you want to connect to: The system database A tenant database

• 3: Choose the authentication type for user logon to the database:
• 4: Choose Finish.

Note: 

1. The system is added in the Systems view. The system entry displays the following information:

   • SID

     In the case of a multitenant database container, the database name is indicated before the SID, either SYSTEMDB@<SID> or <database>@<SID>

   • Connected user
   • System usage if it is a production system
   • System or database description if available

   Information about system availability and user connection status are indicated by icons.

You can now access the system or database in the SAP HANA studio.

HANA Studio administration Guide 

https://help.sap.com/docs/SAP_HANA_PLATFORM/f157e7b47b2a417a99eadd4b6c433b77/608b7dbfcc824b68a0a25b8644282195.html