Today’s data warehouses are expected

to have much higher availability than

those of the past. No longer simply back-

end systems supporting a few power users,

data warehouses are now operational

systems that support hundreds, sometimes

thousands of users in their daily tasks.

Companies have come to realize just how

important their data warehouses are to

their businesses, not only for strategic

decisions but for daily tactical decisions as

well. Service disruptions to the data ware-

house can translate into serious disruption

to the organization.

As a result, a high level of continuous

availability to users is now a requirement,

and more and more companies are moving

to dual-system environments to ensure that

their service level agreements (SLAs) are

met. Additionally, companies employing

dual systems want to maximize the use of

both systems for production workloads,

which requires workload balancing and

system-to-system capacity adjustments.

With dual systems becoming mainstream,

it is important to have a product that allows

powerful yet simplified monitoring, admin-

istration and control of this environment.

Coordinating effortsIn a single-system environment from

Teradata, many tools allow administrators to

monitor the system’s status and take action

as necessary. Here, “system” is defined as a

set of coordinated servers, software and pro-

cesses that accomplish a common goal. The

same is true in a dual-system environment.

While each system runs independently of

the other, the goal of a dual-system environ-

ment from Teradata is to have coordination

between the two—and their supporting

servers and processes—to accomplish a

common goal of meeting pre-defined ser-

vice levels for availability and disaster recov-

ery. To achieve this level of coordination, the

systems must have these capabilities:

> Monitoring. The two Teradata systems

must be monitored along with their

supporting servers and processes;

in effect, the entire data warehouse

environment. This includes tracking

the operational state of each system/

server, the start/stop/completion status

of processes such as data loading and

the currency of data between the two

Teradata systems. It is important to

monitor these and other parameters to

understand whether a given system is

operational and has the required data

to service a query. Knowing what is

happening in the environment is essen-

tial before any action can be taken.

> Administration. Invoking changes to

query routing rules, for example, is

required to maintain SLAs for certain

classes of users. It does not matter

Power2

SERVICES

Teradata Dual Active Solution ensures a smooth ride. by Stan Mlynarczyk, Rick Stellwagen and Imad Birouty

PAGE 1 | Teradata Magazine | September 2008 | ©2008 Teradata Corporation | AR-5721

SERVICES

whether these changes

are manual or auto-

mated, as long as the

ability to administer

the changes exists.

> Control. A dual-

system environment

has the ability to start

and stop processes,

take a system down

for planned mainte-

nance or re-engage

a system after an

unplanned outage.

While monitoring,

administration and control

are described as distinct

capabilities, they are in

reality used in a coordi-

nated fashion to understand

what is happening within the dual-system

environment and, consequently, to take the

desired actions.

Automated managementTeradata Multi-System Manager is part of

the Teradata Dual Active Solution and, as

its name suggests, is designed to handle

multiple Teradata systems. The follow-

ing set of features enables coordination

between systems and allows an organiza-

tion to manage its data warehouse environ-

ment from a single console at the system

and application levels:

> A unified view of a multi-system

environment. A multi-system envi-

ronment includes supporting servers

for data loading, query routing and

applications. A central console enables

a view of the system’s status and key

Monitoring an application across two sites

Figure 1

This at-a-glance view sums up the status and health of an application running at multiple sites. It shows the application’s supporting components, processes and data.

Relying on autopilot

Monitoring and control are critical elements of a

dual system, but no product previously existed

that met the requirements of this type of environment.

So the Teradata Professional Services team created Dual

System Monitor and Control—the foundational architec-

ture for Teradata Multi-System Manager.

In a dual-system environment, Dual System Monitor

and Control can be compared to the instrument panel

in an aircraft’s cockpit—both monitor and manage the

system, both display multitudes of information, and when

problems occur, both activate autopilot.

The solution allows customers to monitor the status of

the dual-system environment, including load jobs, system

alerts, and data and application states. It provides con-

trol over the software, processes and servers that com-

prise the dual-system environment, and sets limits on the

users and applications that route between the systems.

Various levels of detailed information enable users to

see that their applications are operational and per-

forming as expected. A customer’s load architecture is

analyzed to determine how and where to inject instru-

mentation points. Data loads are then instrumented to

automatically broadcast their progress. An alert is sent to

operations when the data latency between the two sys-

tems is above tolerance, and database administrators can

be notified when data consistency issues are identified.

The system’s critical threshold levels are based on

service level agreements for application availability, data

latency and load and response times. When these thresh-

olds are crossed, appropriate alerts are generated and

status changes are visually displayed.

These automated features make it possible for custom-

ers to easily handle a complex dual-system data ware-

house that must be duplicated for reliability and consis-

tency while at the same time be query-accessible.

So, like pilots who rely on their instrument panel, users

can feel assured that the Teradata Multi-System Manager

will help control and enhance the performance of their

dual-system environment.

— Stan Mlynarczyk, director of the Enterprise Architecture

Center of Excellence, Teradata Professional Services

— Mark Mitchell, principal consultant, Teradata Professional

Services

PAGE 2 | Teradata Magazine | September 2008 | ©2008 Teradata Corporation | AR-5721

events within the environment—

everything from a summary view

of the components to a detailed

drill-down of which processes are

running or have been completed on

each system. (See figure 1, page 24.) In

addition, the summary view provides

feedback on the health and opera-

tional status of all components.

> Monitoring of servers, processes and

applications. Beyond a unified view,

intelligent monitoring of numerous

events within the environment is pro-

vided, including detection of system

operational status and the per-system

completion status of processes such as

load jobs.

> Simple point-and-click controls.

Features include a graphical user

interface portal with easy-to-use

controls to manage query routing

rules, engage or disengage a system

for planned maintenance, or bring

a system back online and up to date

after an unplanned outage.

> User routing based on application

readiness state. Sophisticated controls

manage which applications and users

can access which

system based on its

particular data cur-

rency and process

completion. This

capability ensures

that a system is

available and has

current data before

allowing applica-

tion and user access.

(See figure 2.)

> Monitoring

thresholds and dis-

crepancy report-

ing. Managing

multiple loosely

coupled systems

requires a level

of control as to

how current the data is between

the systems. Depending on how the

systems are used and which users

are accessing them, some amount of

data-drift can be tolerated. Anything

beyond this acceptable amount will

require the synchronization lag to be

tightened. Alerts will indicate when

the thresholds are crossed. The system

can also be programmed to take pre-

defined action when this occurs.

> Graceful failover and failback during

planned and unplanned outages.

When the goal is continuous access

for users, one of the most valuable

features in managing a dual-system

environment is the orchestration of

events to handle system outages. This

requires shifting workloads and users

between systems during planned and

unplanned outages. These different

scenarios have varying requirements

to handle the multiple permutations.

Flying highTo accomplish these tasks, Teradata

Multi-System Manager works with other

dual-system products and processes such

as Teradata Query Director and dual load-

ing of data. It controls the Teradata Query

Director profiles and makes modifications

on the fly to accommodate system status

changes. For example, if System A encoun-

ters an unplanned outage, the Query

Director profile is changed, which, in turn,

will engage a new set of routing rules. The

new rules might, for instance, limit routing

to only users with strict SLAs.

During the dual-loading process, the

system monitors the start/stop/completion

status of load jobs. It keeps track of which

jobs have completed and which have not,

and it runs synchronization checks on the

tables to ensure that all of the data was

loaded properly and that the data between

systems is in sync.

Teradata Multi-System Manager can also

be used in a single Teradata production

environment to monitor workflows among

the many application and load processes.

This will benefit Teradata customers who

plan to move from a single production

system to a dual-system environment in

the future.

With dual systems becoming main-

stream, it is important to have a solid

product that simplifies monitoring, admin-

istration and control of the environment.

Teradata Multi-System Manager provides

these capabilities with powerful features

that are efficient, dependable and simple

to use. T

Stan Mlynarczyk is director of the

Enterprise Architecture Center of Excellence

in Teradata Professional Services.

Rick Stellwagen is the engineering architect

for Teradata multi-system solutions.

Imad Birouty is program marketing man-

ager for the high-availability solutions and

data mart consolidation program at Teradata.

TOnlineFor more information,

visit Teradata.com/

DualActiveSolutions.

Summary view of all applications across two sites

Figure 2

The status and health of all Teradata ecosystems are monitored, and a condensed view is supplied of multiple applications and their conditions at each site.

PAGE 3 | Teradata Magazine | September 2008 | ©2008 Teradata Corporation | AR-5721