O'Reilly logo

Implementing BEA Portal 92 by Mark Kolb

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Designing Your Portal

All my examples will be based on the premise that business wants a design that can yield 99.9 percent application availability for an enterprise level of support.Many people discuss availability and say different comments: "I want it available 24-7," "It can never go down," or, my favorite, "It can never go down between 8:00 A.M. and 6:30 P.M.". We are engineers, and we deal with numbers. I've included a handy table to put hard numbers on different levels of availability. As far as keeping it up between 8:00 A.M. and 6:30 P.M., you need High Availability (HA) in your design just the same.

Note

Table 1. Availability table

Percentage Available

 

98%

99%

99.90%

99.99%

99.999%

       

Minutes/Day

1440

28.8

14.4

1.44

0.144

0.0144

Minutes/Month

43200

864

432

43.2

4.32

0.432

Minutes/Year

525600

10512

5256

525.6

52.56

5.256

       

Hours / Day

24

0.48

0.24

0.024

0.0024

 

Hours / Month

720

14.4

7.2

0.72

0.072

 

Hours / Year

8760

175.2

87.6

8.76

0.876

 

According to this table, our design will allow for approximately 44 minutes of unscheduled downtime a month. That's an important point as you craft your SLA with the business and you set your customers' expectations. What design guarantees that delivery of service? A lot depends on your experience and the state of the technology, but you cannot deliver anything more than 98 percent without redundancy on all levels. Also important to note is that you want to design your environment to allow for the availability required as well as allow for growth over a reasonable life for ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required