Re:Next-Generation IBM POWER10 Processor
by jiggawatts on Monday August 17, 2020 @11:16PM
(#24194893)
Not for any single user or connection. High capacity doesn't equal low latency, and scalability to many users doesn't necessarily help one user get better performance!
Very often, you'll see n-tier applications where for some reason (typically load-balancers), the requests are muxed into a single TCP stream. In the past, this improved efficiency by eliminating the per-connection overhead.
Now, with high core counts and high bandwidths, some parallelism is absolutely required to even begin to approach the performance ceiling. If the application is naturally single-threaded, such as some ETL jobs, these single-stream bottlenecks are very difficult to overcome.
In the field, I very often see 8-core VMs with a "suspicious" utilisation graph flatlining at 12.5% because of issues like this. It boils my blood when people say that this is perfectly fine, because clearly the server has "adequate capacity". In reality, there's a problem, and the server is at 100% of its capacity an the other 7 cores are just heating the data centre air.
Very often, you'll see n-tier applications where for some reason (typically load-balancers), the requests are muxed into a single TCP stream. In the past, this improved efficiency by eliminating the per-connection overhead.
Now, with high core counts and high bandwidths, some parallelism is absolutely required to even begin to approach the performance ceiling. If the application is naturally single-threaded, such as some ETL jobs, these single-stream bottlenecks are very difficult to overcome.
In the field, I very often see 8-core VMs with a "suspicious" utilisation graph flatlining at 12.5% because of issues like this. It boils my blood when people say that this is perfectly fine, because clearly the server has "adequate capacity". In reality, there's a problem, and the server is at 100% of its capacity an the other 7 cores are just heating the data centre air.