As a ball-park estimate, we like to see at least 1MB of dedicated
physical RAM per simulated agent, e.g., a 100 agent scenario should run
fine on a 128MB system (depending on how much memory is used by the OS
and other processes). For better performance (less swapping), 2MB per
agent is recommended. When the agents are running the same simulation,
MIMIC optimizes memory usage to contain only one copy of the simulation
data for all agents of the same type.
You can more accurately measure this by running a simulation
configuration, and checking on memory usage before and after starting
the desired agent simulations. Notice that MIMIC uses memory on demand,
so you should measure the memory after doing a walk of the desired tables
(or a complete MIB walk). Eg. On Windows NT use the Windows Task Manager
to check "Memory Usage", and on Unix use the "top" utility. The memory
usage by MIMIC is approximately the same for all platforms.
The CPU is of secondary importance. Most modern processors (e.g.,
Intel Pentium 3GHz or faster) are adequate. MIMIC
works with multi-processor systems, since it is a multi-threaded,
distributed application. Agent thread processing will be distributed
across multiple CPUs.
The final bottleneck would be the network pipe to your agents. 10Mb
Ethernet is adequate for low-volume traffic, 100Mb or 1Gb is better for
more demanding applications. MIMIC works with multiple network adapters
on your system, so you can talk to the simulations over separate network
MIMIC works with the OS-native protocol stacks, so that all network
interface cards that your
OS supports can be used. You can even run MIMIC over PPP or wireless.
MIMIC - The Right Decision
When you are making a decision to buy a simulator for scalability testing,
your concerns about feasibility and performance are very valid. We make
sure that MIMIC can simulate the number of agents you buy on a reasonably
sized system, which gives you adequate performance numbers. This is why we
have an upper limit of 50,000 agents. We don't believe in offering a vague
number like "unlimited" because there is no such thing as "unlimited"
when you have operating system, CPU and memory limitations.
We strongly recommend doing comparison tests with a large number of SNMP
agents. You will find that no other products in the market can reach
the desired number (above 1,000) of agents plus, the performance for
a large number of agents is not even close to what you get with MIMIC.
MIMIC's numbers are drastically better.
You're embarking on a critical decision on what solution is right for
scalability; you owe it to yourself to do the comparisons.