crimsonalucard1
Joined 6 years ago
Joined 6 years ago
This is my claim that this SHOULD be what's happening under the obvious logic that tasks handled in parallel to IO should be faster then tasks handled sequentially and under the assumption that IO takes up way more time then local processing.
Like I said the fact that this is NOT happening within the python ecosystem and assuming the axioms above are true, then this indicates a flaw that is python specific.
>The reason the interpreter matters is because the latency picture of async is very linear:
I would say it shouldn't matter if done properly because the local latency picture should be a fraction of the time when compared to round trip travel time and database processing.
>Python is likely slow because it implements the event loop in python
Yeah, we're in agreement. I said it was a python specific problem.
If you take a single task in this benchmark for python. And the interpreter spends more time processing the task locally then the total Round trip travel time and database processing time... Then this means the database is faster than python. If database calls are faster then python then this is a python specific issue.
It's data science that is causing this data driven attitude to invade peoples minds. Do you not realize that logic and assumptions take a big role in drawing conclusions WITHOUT data? In fact if you're a developer you know about a way to DERIVE performance WITHOUT a single data point or benchmark or profile. You know about this method, you just haven't been able to see the connections and your model about how this world works (data driven conclusions only) is highly flawed.
I can look at two algorithms and I can derive with logic alone which one is O(N) and which one is O(N^2). There is ZERO need to run a benchmark. The entire theory of complexity is a mathematical theory used to assist us at arriving AT PERFORMANCE conclusions WITHOUT EVIDENCE/BENCHMARKS.
Another thing you have to realize is the importance of assumptions. Things like 1 + 1 = 2 will remain true always and that a profile or benchmark ran on a specific task is an accurate observation of THAT task. These are both reasonable assumptions to make about the universe. They are also the same assumptions YOU are making everytime you ask for EVIDENCE and benchmarks.
What you aren't seeing is this: The assumptions I AM making ARE EXACTLY THE SAME: reasonable.
>you're asserting something without actual evidence, and the article itself doesn't actually state that either: it contains no breakdown of where the time is spent
Let's take it from the top shall we.
I am making the assumption that tasks done in parallel ARE Faster than tasks done sequentially.
The author specifically stated he made a server that where each request fetches a row from the database. And he is saying that his benchmark consisted of thousands of concurrent requests.
I am also making the assumption that for thousands of requests and thousands of database requests MOST of the time is spent on IO. It's similar to deriving O(N) from a for loop. I observe the type of test the author is running and I make a logical conclusion on WHAT SHOULD be happening. Now you may ask why is IO specifically taking up most of the time of a single request a reasonable assumption? Because all of web development is predicated on this assumption. It's the entire reason why we use inefficient languages like python, node or Java to run our web apps instead of C++, because the database is the bottleneck. It doesn't matter if you use python or ruby or C++, the server will always be waiting on the db. It's also a reasonable assumption given my experience working with python and node and databases. Databases are the bottleneck.
Given this highly reasonable assumption, and in the same vein as using complexity theory to derive performance speed, it is highly reasonable for me to say that the problem IS PYTHON SPECIFIC. No evidence NEEDED. 1 + 1 = 2. I don't need to put that into my calculator 100 times to get 100 data points for some type of data driven conclusion. It's assumed and it's a highly reasonable assumption. So reasonable that only an idiot would try to verify 1 + 1 = 2 using statistics and experiments.
Look you want data and no assumptions? First you need to get rid of the assumption that a profiler and benchmark is accurate and truthful. Profile the profiler itself. But then your making another assumption: The profiler that profiled the profiler is accurate. So you need to get me data on that as well. You see where this is going?
There is ZERO way to make any conclusion about anything without making an assumption. And Even with an assumption, the scientific method HAS NO way of proving anything to be true. Science functions on the assumption that probability theory is an accurate description of events that happen in the real world AND even under this assumption there is no way to sample all possible EVENTS for a given experiment so we can only verify causality and correlations to a certain degree.
The truth is blurry and humans navigate through the world using assumptions, logic and data. To intelligently navigate the world you need to know when to make assumptions and when to use logic and when data driven tests are most appropriate. Don't be an idiot and think that everything on the face of the earth needs to be verified with statistics, data and A/B tests. That type of thinking is pure garbage and it is the same misguided logic that is driving your argument with me.
It's not odd. Think harder. I'm saying under the benchmark and according to the logic of what SHOULD be going on under AsyncIO it SHOULD be negligible. So such performance issues between python and node SHOULDN'T matter, and that's why you CAN compare NodeJS and Python.
But actual testing does show an unexpected discrepancy that says that the problem is python specific because logically there's No other explanation.
>You're really sure that there's no context where the accuracy gained by relativity would be useful?
Dude I already know about that. I just didn't bring it up, because I'm giving you an example to help you understand what "NEGLIGIBLE" means. You're just being a pedantic smart ass.
There are many many cases where relativity is not needed because it's negligible. In fact the overwhelming majority of engineering problems don't need to touch relativity. You are aware of this I am aware of this. No need to be a pedantic smart ass. The other thing that gets me is that it's not even anything new, many people know about how satellites travel fast enough for relativity to matter.
>Again, this is you making stuff up
Dude nothing was made up.
I never said "there's no context where the accuracy gained by relativity would be useful". "No context" is something YOU made up.
In fact "made up" is too weak of a word. A better word is an utter lie.
That's right. You're a liar. I'm not being rude. Just making an observation. Embarrassed yet?
And I'm saying all those confounding variables you're talking about are negligible and irrelevant.
Why? Because the benchmark test in the article is a test where every single task is 99% bound by IO.
What each task does is make a database call AND NOTHING ELSE. Therefore you can safely say that for either python or Node request less than 1% of a single task will be spent on processing while 99% of the task is spent on IO.
You're talking about scales on the order of 0.01% vs. 0.0001%. Sure maybe node is 100x faster, but it's STILL NEGLIGIBLE compared to IO.
It it _NOT_ Nonsense.
You Do not need an apples to apples comparison to come to the conclusion that the problem is Specific to the python implementation. There ARE NO confounding variables.
Hey Genius. Look at the test that the benchmark ran. The benchmark is IO bound. This is SPECIFIC test about IO bound processes. The benchmark is not referring to real world applications it is SPECIFICALLY referring to IO.
The literal test is thousands of requests and for each handler for those requests ALL it does is query a database. If you look at a single request almost 99% of time is spent on IO.
Due to the above, Anything that has to do with the python interpreter, JIT, garbage collection and reference counting becomes NEGLIGIBLE in the context of the TEST in the ARTICLE ABOVE. I suspect you didn't even read it completely.
Does that concept make sense to you? You can use relativity rather then newtonian physics to calculate the trajectory of a projectile BUT it is involves UNNECESSARY overhead coming from Relativity because the accuracy gained from the extra calculations ARE NEGLIGIBLE.
>You are, in fact, making stuff up. If you are offended by accurate description of your behavior, behave better.
Now that things have been explained completely clearly to you, do you now see how you are the one who is completely wrong or are you incapable of ever admitting your wrong and apologizing to me like you should? I mean literally that statement above is embarrassing once you get how wrong you are.
All that matters is the concurrency model because that application he's running is barely doing anything else except IO and anything outside of IO becomes negligible because after enough requests, those sync worker processes will all be spending the majority of their time blocked by an IO request.
The basic essence of the original claim is that sync is not necessarily better than async for all cases of high IO tasks. I bring up node as a counter example because that async model IS Faster for THIS same case. And bringing up node is 100% relevant because IO is the bottleneck, so it doesn't really matter how much faster node is executing as IO should be taking most of the time.
Clearly and logically the async concurrency model is better for these types of tasks so IF tests indicate otherwise for PYTHON then there's something up with python specifically.
You're right, we are in disagreement. I didn't realize you completely failed to understand what's going on and felt the need to do an apples to apples comparison when such a comparison is not Needed at all.
So really we're in agreement. You're talking about reimplementing python specific things to make it more performant, and that is exactly another way of saying that the problem is python specific.
NodeJS is faster than flask because of the concurrency model and NOT because of the JIT.
The python async implementation being slower than the python sync implementation means one thing: Something is up with python.
The poster implies that with the concurrency model the outcome of these tests are expected.
The reality is, these results are NOT expected. Something is going on specifically with the python implementation.
So you have two implementations of async that are both bottlenecked by IO. One is implemented in node. The other in python.
The node implementation behaves as expected in accordance to theory meaning that for thousands of IO bound tasks it performs faster then a fixed number of sync worker threads (say 5 threads).
This makes sense right? Given thousands of IO bound tasks, eventually all 5 threads must be doing IO and therefore blocked on every task, while the single threaded async model is always context switching whenever it encounters an IO task so it is never blocked and it is always doing something...
Meanwhile the python async implementation doesn't perform in accordance to theory. 5 async workers is slower then 5 sync workers on IO bound tasks. 5 sync workers should eventually be entirely blocked by IO and the 5 async workers should never be blocked ever... Why is the python implementation slower? The answer is obvious:
It's python specific. It's python that is the problem.
So you harvest CO2 to into fuel. That fuel is burned and the CO2 is released back into the air. So net difference is zero.
But to harvest the CO2 you needed to generate a high amount of heat. That's extra CO2. So net CO2 is more.
It depends on the cost of harvesting that CO2.