In response to the question, i think the answer depends on our definition of performance. Low latency would be important as it measures how fast we can access the site, and all its resources. If we want a web site that is fast to access for any single user, then we want low latency. Throughput is the transactions per second the site can handle. If the site has many hits at any 1 time, we want high throughput or else eventually, the hits will increase to a point where the site gets overloaded, and it either crashes or becomes staggeringly slow for users. If we measure performance by how much load a site is able to handle (i.e., being able to function normally even with a high amount of hits), then high throughput is more important.
This comment was marked helpful 1 times.
wcrichto
Previously in the course, we've seen that throughput tends to have an inverse relation with latency. However, it seems to be the case here (as @elemental03 noted) that on the web we find more of a direction relation between the two. Adding more servers probably doesn't reduce latency in the same way a scheduler might optimize throughput by increasing individual latencies. Here, giving more throughput almost always decreases the latency of transferring files to clients.
This comment was marked helpful 0 times.
jinsikl
@wcrichto I don't really understand your comment. The slide you linked is showing how a single core might context switch between multiple processes in order to increase throughput. One side effect is that this will increase latency as the core might not be running a process as soon as it becomes runnable. So adding a new server isn't analogous to adding a new context for a core to run, it's like adding an entirely new core. And adding an extra core should decrease latency, as long as there's enough work to be done.
This comment was marked helpful 1 times.
paraU
I think the answer is both. In the common situation, if the system have a short latency it could have a higher throughput because the execution time of each task is shorter.
This comment was marked helpful 0 times.
chaihf
Some websites are persuing low latency in order to give clients good using experiences. Think about using Facebook, you don't want to sit there for several seconds just waiting for latest posts, so Facebook may feed you with some posts (maybe not latest) as fast as they can. In this scenario, clients feels good with low latency, while high throughput does not give us a direct feeling.
In response to the question, i think the answer depends on our definition of performance. Low latency would be important as it measures how fast we can access the site, and all its resources. If we want a web site that is fast to access for any single user, then we want low latency. Throughput is the transactions per second the site can handle. If the site has many hits at any 1 time, we want high throughput or else eventually, the hits will increase to a point where the site gets overloaded, and it either crashes or becomes staggeringly slow for users. If we measure performance by how much load a site is able to handle (i.e., being able to function normally even with a high amount of hits), then high throughput is more important.
This comment was marked helpful 1 times.
Previously in the course, we've seen that throughput tends to have an inverse relation with latency. However, it seems to be the case here (as @elemental03 noted) that on the web we find more of a direction relation between the two. Adding more servers probably doesn't reduce latency in the same way a scheduler might optimize throughput by increasing individual latencies. Here, giving more throughput almost always decreases the latency of transferring files to clients.
This comment was marked helpful 0 times.
@wcrichto I don't really understand your comment. The slide you linked is showing how a single core might context switch between multiple processes in order to increase throughput. One side effect is that this will increase latency as the core might not be running a process as soon as it becomes runnable. So adding a new server isn't analogous to adding a new context for a core to run, it's like adding an entirely new core. And adding an extra core should decrease latency, as long as there's enough work to be done.
This comment was marked helpful 1 times.
I think the answer is both. In the common situation, if the system have a short latency it could have a higher throughput because the execution time of each task is shorter.
This comment was marked helpful 0 times.
Some websites are persuing low latency in order to give clients good using experiences. Think about using Facebook, you don't want to sit there for several seconds just waiting for latest posts, so Facebook may feed you with some posts (maybe not latest) as fast as they can. In this scenario, clients feels good with low latency, while high throughput does not give us a direct feeling.
This comment was marked helpful 0 times.