Using OASIS in a Terminal Server Environment

This document contains basic information on using OASIS in a terminal server environment. Our hope that this document will allow a business executive to have a basic understanding of how utilizing a terminal server to host the OASIS database will affect OASIS users and database performance.

Background

This document was created to give a high level overview of some ways a terminal server can be improperly sized and implemented, which can cause performance issues and user complaints. 

What is a Terminal Server?

A terminal server uses Microsoft Terminal Services to allow a user to connect to a remote server using Remote Desktop, giving them a full desktop environment to work in. 

What should my IT group consider?

Several factors in the existing environment need to be considered:

• How large is the database? 
• How much RAM is the database using on average? 
• How much swap space is the database using? 
• How many users will be accessing the database? 

Cloud Based Database Servers and Terminal Servers

When building a combined database server and terminal server solution, you must keep in mind how cloud services providers work. They provide shared resource pools to keep prices competitive. When you deploy a virtual machine to a cloud environment, you aren't seeing the full picture. While your Windows instance might be showing only 10% usage across 4 CPU cores, those CPU cores are actually being shared between several other customers, and could possibly be at a constant 80% utilization. This can often cause your instance of OASIS to wait for CPU clock cycles. The same is especially true for storage. While your Windows instance may show low utilization for your virtual disks, the truth is that several other customers on the shared storage pool are doing things requiring a lot of disk I/O. While the cloud provider might be using a high end storage controller, you will not get the same performance as you would with dedicated storage. 

Recommendations

When sizing the server, keep the following OASIS-specific needs in mind:

• The OASIS client by default can use up to 1 GB of RAM. At idle, it uses ~250 MB RAM. For 32 bit clients, there is a separate icon to launch OASIS using 1.5 GB of RAM. For 64 bit clients, there is a separate icon to launch OASIS using 2 GB of RAM. Actual usage will vary from OASIS user to OASIS user, depending on their role at the company. Users that multitask or tend to run large reports need a 64 bit installation specifically for access to the 2G icon because some large reports require that much memory to run (and sometimes require more). 

• The OASIS database is a SAP Sybase SQL Anywhere 16 database. Its RAM needs will vary based on the size of the database, the number of users connecting, and the features of OASIS that are utilized by the company. 

• If possible, choose dedicated storage instead of shared storage.