performance

问题 According to Marcin Ciura's Optimal (best known) sequence of increments for shell sort algorithm, the best sequence for shellsort is 1, 4, 10, 23, 57, 132, 301, 701..., but how can I generate such a sequence? In Marcin Ciura's paper, he said: Both Knuth’s and Hibbard’s sequences are relatively bad, because they are defined by simple linear recurrences. but most algorithm books I found tend to use Knuth’s sequence: k = 3k + 1, because it's easy to generate. What's your way of generating a

问题 My Vagrant box running a classic LAMP stack (ubuntu 14, php 5.5.9) serves pages slowly (~ 5.3/5.5 secs) if more than 60 seconds passed since last page load. The "normal" page load (before passing the 60 secs limit) is ~0.2 sec. The application files are shared from the host system via NFS. What I've debugged so far: it only happens to requests hitting the application (which is a laravel 5 application) happens even if no queries are made to the db if I die() at the very top of the application

问题 In my application i want to send current location and time continuously each 5min In case network is not available app has to store data (here im using sqlite to store) and send data once network enabled or internet connected. i goggled lot but i could see only can check mobile or wifi network enabled or not. in some cases wifi or mobile network may be enabled but internet will not be work. In this case how can i find internet is working or not? I hope you got my problem 回答1: The

问题 Given a number n how fast can one find the smallest number with most factors and is less than n? PS:other than the naive approach of finding number of divisors for all numbers upto n . UPDATE : My observation: int solve(int primes[],int s,int n) { int i=0; while(s<n) { s*=primes[i]; i++; } if(s>n) s/=primes[i-1]; return s; } int main() { int primes[] = {2,3,5,7,11,13,17,19,23,29,31,37}; int n; scanf("%d",&n); int s=1; while(s*2<n)//checking the possibility of existence of any prime such that

问题 Hey awesome Stackoverflow people I am currently evaluating if we should use iText 7.1.9 for Java or C#. To do this, I created a test case where I write a single PDF with a bunch of pages, each containing a big table (code below). In Java, creating a PDF with x pages yields the following results: 1 page: 0 sec 10 pages: 1 sec 100 pages: 5 sec 1000 pages: 23 sec This is reasonably performant. However, when I ported the exact same code to C# .Net, I got quite the shock: 1 page: 0 sec 10 pages: 1

问题 Recently I got question about which one is the most fastest thing among iterator , list comprehension , iter(list comprehension) and generator . and then make simple code as below. n = 1000000 iter_a = iter(range(n)) list_comp_a = [i for i in range(n)] iter_list_comp_a = iter([i for i in range(n)]) gene_a = (i for i in range(n)) import time import numpy as np for xs in [iter_a, list_comp_a, iter_list_comp_a, gene_a]: start = time.time() np.sum(xs) end = time.time() print((end-start)*100) the

问题 Recently I got question about which one is the most fastest thing among iterator , list comprehension , iter(list comprehension) and generator . and then make simple code as below. n = 1000000 iter_a = iter(range(n)) list_comp_a = [i for i in range(n)] iter_list_comp_a = iter([i for i in range(n)]) gene_a = (i for i in range(n)) import time import numpy as np for xs in [iter_a, list_comp_a, iter_list_comp_a, gene_a]: start = time.time() np.sum(xs) end = time.time() print((end-start)*100) the

问题 Hey awesome Stackoverflow people I am currently evaluating if we should use iText 7.1.9 for Java or C#. To do this, I created a test case where I write a single PDF with a bunch of pages, each containing a big table (code below). In Java, creating a PDF with x pages yields the following results: 1 page: 0 sec 10 pages: 1 sec 100 pages: 5 sec 1000 pages: 23 sec This is reasonably performant. However, when I ported the exact same code to C# .Net, I got quite the shock: 1 page: 0 sec 10 pages: 1

问题 Recently I got question about which one is the most fastest thing among iterator , list comprehension , iter(list comprehension) and generator . and then make simple code as below. n = 1000000 iter_a = iter(range(n)) list_comp_a = [i for i in range(n)] iter_list_comp_a = iter([i for i in range(n)]) gene_a = (i for i in range(n)) import time import numpy as np for xs in [iter_a, list_comp_a, iter_list_comp_a, gene_a]: start = time.time() np.sum(xs) end = time.time() print((end-start)*100) the

问题 I have been using Spark Data Source to write to Kudu from Parquet, and the write performance is terrible: about 12000 rows / seconds. Each row roughly 160 bytes. We have 7 kudu nodes, 24 core + 64 GB RAM each + 12 SATA disk each. None of the resources seem to be the bottleneck: tserver cpu usage ~3-4 core, RAM 10G, no disk congestion. Still I see most of the time write requests were stuck in queuing. Any ideas are appreciated. W0811 12:34:03.526340 7753 rpcz_store.cc:251] Call kudu.tserver