I believe throughput will be fairly high/maximum possible under heavy load since all of our resources are busy servicing requests at any given time. Am I right to say so?
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arjunh
@rokhinip I think that's a reasonable assumption to make, but there are a few things that could possibly reduce the net throughput when the system is under heavy load. These things have to do with the physical limitations of the communication lines that carry the worker responses to the clients and the overheads that arise from substantial sharing of such resources:
Packet Loss: Network congestion leads to switches and routers dropping off packets due to long wait queues. Also, I think that higher congestion will lead to more invalid packets being received due to bit errors, simply because greater network congestion leads to more noise/interference over the communication lines
Collisions: Network congestion also leads to more packets colliding with each other. Policies to handle collisions typically involve some mechanism where the sender detects other messages being sent over the interconnect and waits for a random period of time before resending (similar to the 'snooping' mechanism used in our cache coherence algorithms). An example of such algorithms is Carrier sense multiple access with Collision Detection (CSMA/CD). Either way, this incurs a performance hit on the system throughput.
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Yuyang
@arjunh I think what you said makes sense, though I don't think Packet Loss and Collisions are not going to affect the server throughput because those scenarios would only likely to happen once there is already a long queue. Once we have a big queue, the server is already always busy.
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idl
@rokhinip Yes you're right to say so. The fact that all resources are busy is really good for throughput. However, the negative side of this is that latency might be affected because the resources available to the system are shared by so many users.
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mofarrel
All resources are being well used under high load, this means that they are achieving a high throughput. Increasing the amount of resources (eg. servers) may still increase throughput by allowing us to service more requests at once. Adding these servers would hopefully allow us to drain the queues as well (decreasing latency).
If the throughput is higher than the input, the queues will drain. If the throughput is to lower then the queues will build (adding latency).
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taegyunk
For those of who interested in mathematical background of analyzing/modeling server load/server service rate/server failure rate, consider taking 15-359 or 15-857A.
I believe throughput will be fairly high/maximum possible under heavy load since all of our resources are busy servicing requests at any given time. Am I right to say so?
This comment was marked helpful 0 times.
@rokhinip I think that's a reasonable assumption to make, but there are a few things that could possibly reduce the net throughput when the system is under heavy load. These things have to do with the physical limitations of the communication lines that carry the worker responses to the clients and the overheads that arise from substantial sharing of such resources:
Packet Loss: Network congestion leads to switches and routers dropping off packets due to long wait queues. Also, I think that higher congestion will lead to more invalid packets being received due to bit errors, simply because greater network congestion leads to more noise/interference over the communication lines
Collisions: Network congestion also leads to more packets colliding with each other. Policies to handle collisions typically involve some mechanism where the sender detects other messages being sent over the interconnect and waits for a random period of time before resending (similar to the 'snooping' mechanism used in our cache coherence algorithms). An example of such algorithms is Carrier sense multiple access with Collision Detection (CSMA/CD). Either way, this incurs a performance hit on the system throughput.
This comment was marked helpful 1 times.
@arjunh I think what you said makes sense, though I don't think Packet Loss and Collisions are not going to affect the server throughput because those scenarios would only likely to happen once there is already a long queue. Once we have a big queue, the server is already always busy.
This comment was marked helpful 0 times.
@rokhinip Yes you're right to say so. The fact that all resources are busy is really good for throughput. However, the negative side of this is that latency might be affected because the resources available to the system are shared by so many users.
This comment was marked helpful 0 times.
All resources are being well used under high load, this means that they are achieving a high throughput. Increasing the amount of resources (eg. servers) may still increase throughput by allowing us to service more requests at once. Adding these servers would hopefully allow us to drain the queues as well (decreasing latency).
If the throughput is higher than the input, the queues will drain. If the throughput is to lower then the queues will build (adding latency).
This comment was marked helpful 1 times.
For those of who interested in mathematical background of analyzing/modeling server load/server service rate/server failure rate, consider taking 15-359 or 15-857A.
This comment was marked helpful 1 times.