Databases Reference
In-Depth Information
Figure 1-5.
Completing the Installation wizard
Beside the issues of licensing, there is another issue that might affect whether you install the OHS on
the same machine or a different machine than the database software. That issue is
network latency
.
When the OHS is on the same machine as the database software, the network connection from the OHS
to the database (via the
mod plsql
handler) is within the same machine so there is very little network
overhead. When you install the OHS on a machine other than the machine the database software is
installed on, there is an additional—perhaps negligible, but still measurable—network overhead
involved in the transmission of data between the two machines. While this overhead might be small, it
does still all add up; as you increase the number of end users of your application(s), the overhead might
become more and more noticeable, depending on your infrastructure.
If I had to summarize the two options, I'd say the advantages to installing on the same machine are
as follows:
•
No additional licensing required
•
Reduced network latency
Disadvantages to installing on the same machine are
•
Out of control OHS process could affect the database (unless operating system
resource controls are used).
•
If a hacker managed to exploit the OHS, they could control the database machine.
Advantages to installing on different machines are
•
More secure configuration (better physical separation)
•
Easier to scale out (add more web server layers)
