Caveats
All of the information in this document is based on the years of experience our product developers and system
administrators can offer. Following are some of the caveats they want you to know as you interpret the
best-utilization information included in this document.
Java Applications
Java applications may be used on the Pro Plus plan only. This is because many Java applications consume significant
CPU and memory resources and some may not be appropriate for use in the FreeBSD VPS v3 environment. Java applications
on FreeBSD VPS v3 should be monitored and possibly restricted for use only on Websites with a low expected workload.
In addition, some larger Java applications may not be suitable for use on FreeBSD VPS v3 even with low workloads. You
must conduct sufficient performance testing of your Java application on a FreeBSD VPS v3 before relying on it for
critical business needs. You must build contingency plans in case your Java application does not perform as expected;
possible solutions may include:
- Extensive optimization of the Java application
- Moving the Java application to a dedicated server such as the Managed Private Server (MPS).
- Implementing an alternative solution to using Java. (For example, moving from Java to an optimized C program.)
There are a wide range of Java-based applications. Some are designed to handle multiple services and others focus on
a smaller range of services. As an example, Zimbra (http://www.zimbra.com/) is open-source server and client software
used to process email, group calendaring, and contacts. In addition, the software supports Web document management
and authoring. The software offers a wide range of services, some of which duplicate applications included with the
default configuration of the Pro Plus plan. The software offers these services by drawing on Java and its own,
duplicate installation of Tomcat. These factors make the software better suited to a more powerful, dedicated
server offering such as MPS.
Alternatively, JSP Wiki (http://www.jspwiki.org/) uses standard Java 2 Platform, Enterprise Edition (J2EE) components
such as Java, servlets, and JSP. The software enables collaborative authoring for Websites (also called a wiki). The
software enables visitors to collectively comment upon, add to, or remove from Web page content. The open-source
software focuses on providing a singular, unique service. It does this by utilizing the Java components which are
available for installation on the Pro Plus plan. JSP Wiki does not duplicate services which are also supported by
FreeBSD VPS v3, such as email.
JSP Wiki is an example of a Java-based application which is well-suited to the Pro Plus plan when put under low to
moderate workloads. Results will vary by application, but a JSP Wiki installation running on the Pro Plus plan could
potentially handle up to tens of thousands of wiki page views per day. Should hundreds of thousands of wiki page
views per day be required, upgrading to a dedicated server such as a Managed Private Server (MPS) is recommended.
Interdependence
Some aspects of your plan’s performance are interdependent. Resources are not dedicated to specific applications or
tasks; you have a finite number of resources (as described in Table 2) for all of your tasks. The usage guidelines
described in this document should be applied with this in mind. For example, if you have a busy Website, your
ability to process high volumes of email will be impaired. Or, as another example, there are not additional
resources specifically allocated for processing emails sent and received, performance depends on the total
mailing list size (or volume). If, on an average day, mailing list activity is high, and you also expect a
high volume emails sent and received, then you must take measures to schedule those activities or you might
consider upgrading to a plan with sufficient resources for processing all of the emails sent and received,
as well as for mailing list usage.
Sandboxes and Performance
Each FreeBSD VPS v3 operates in a sandboxed environment that protects, but does not always prevent, performance
from being impacted by another FreeBSD VPS v3 accounts. All customers share some common server resources including
CPU, memory, network, and disk space. Resource availability is not guaranteed.
For Informational Purposes Only
This information is provided for informational purposes only and must be recognized as providing information about
best-utilization (as opposed to performance guarantees or service-level agreements). Operating system-level
virtualization technology combined with sound server administration practices enable resources to adjust as
required in order to preserve an optimal operating environment for all FreeBSD VPS v3 customers.
Fluctuations and Adjustments
Actual resource availability may fluctuate both above and below the values in this document. Ultimately, the
demand on available resources will determine the performance of each FreeBSD VPS v3 plan. While this information
may be helpful in gauging appropriate usage, it should not be the sole determinate in capacity planning. The Web
host reserves the right to adjust FreeBSD VPS v3 resources as required. These adjustments preserve optimal operating
environment for all FreeBSD VPS v3 accounts.
|
