Report Database Recommendations and Bandwidth Usage
You can have a single Apple Remote Desktop data collection database for any number
of clients. However, avoid having all the clients upload their report information at the
same time. As the number of clients grows, the network usage from the clients as they
upload their report data could come in bursts over a short period of time
overwhelming the network buffer on the Task Server. In such a case, you will probably
give yourself your own denial-of-service attack. Increasing the number of Task Server
computers can divide the network and computing load among several computers for
better performance and better network citizenship. However, since there is no way to
aggregate report data across several collectors and display it on one administrator
computer, you would need multiple administrators to balance your network load in
this manner.
If you use a single database for a large number of clients, it is recommended that you
stagger the generation of report caches over the time between which you want to run
reports. For example, if you normally run a report every week, then set 1/7th of your
clients to rebuild caches on day one, another 1/7th for the next day and so on.
Additionally, they should stagger the cache rebuild over the course of the day as well.
It is recommended that you keep in a given list the minimum number of computers
necessary for your purposes. When a list is selected, the clients in the list send status
updates at a minimum of every 20 seconds. If you have a large number of clients in a
list (for example, 1000), this makes about 50 updates a second.
Creating more lists doesn’t create more resource overhead for Remote Desktop, and
can allow you to quickly and easily administer the clients you want with a minimum
wait. Depending on your network and list sizes, you may find that smaller lists may
result in more productive and reliable administration.
What Bandwidth Does the Default System Overview Report Use on a LAN?
The average System Overview Report cache is about 20 KB. While reporting, the admin
and clients will always try to use all available bandwidth (most IP-based client/server
applications work this way). Therefore, on a 10Mbit/sec. network, the report data
collection for a single client may use 100% of the bandwidth for a period of 0.016
seconds. Assuming a list of 1000 computers, all trying to report at the same time, this
may use 100% of the bandwidth for 16 seconds. Naturally, faster networks will perform
better, and networks with a slow bottleneck like a DSL or modem line perform worse.
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Chapter 8
Administering Client Computers
System Report Size
The file system data which is uploaded to the report database (labeled “File Search
data” in the Scheduling sheet of the Task Server preference pane) contains a significant
amount of data. For a client with 10 GB of files on the hard disk, the report data
uploaded can easily reach 5 MB in size. With hundreds or thousands of clients, this data
can add up quickly and might tax network resources. Data for other reports (System
Overview, Application Usage, and User History) are only 8 KB to 12 KB each, and have
little impact.
Uploading user accounting data and application usage data further increases the size
of the uploaded data for any one client. Since you may not want to store all the
possible information for a given client computer, you can customize which type of data
is collected, as desired.