How many records can i store in a Sql server table before it's getting ugly?

i've been asked to do some performance tests for a new system. It is only just running with a few client, but as they expect to grow, these are the numbers i work with for my test: 200 clients, 4...

How to clone weblogic server in WLST (offline-mode)?

We have a custom weblogic template which has admin server (obviously) and a cluster with 2 managed servers deployed to the same machine. We use that template for our development environments. But...

Why does the Contains() operator degrade Entity Framework's performance so dramatically?

UPDATE 3: According to this announcement, this has been addressed by the EF team in EF6 alpha 2. UPDATE 2: I've created a suggestion to fix this problem. To vote for it, go here. Consider a SQL...

Why is .Contains slow? Most efficient way to get multiple entities by primary key?

What's the most efficient way to select multiple entities by primary key? public IEnumerable<Models.Image> GetImagesById(IEnumerable<int> ids) { //return ids.Select(id => Images.Find(id)); ...

Zend Framework controller issue

This has to be the most frustrating and mind boggeling problem i have encountered so far. I have a small demo project wich has about 5 controllers. When i go to the project using the url...

ASP.Net 1.1 to ASP.Net 4.0 Migration

We are migrating our existing code written in ASP.Net 1.1 to ASP.Net 4.0. We also need to migrate our web controls as well. We have 50% or more pages has DataGrid used and from ASP.Net 2.0 we have...

How does PostgreSQL perform writes so much faster than SQLite?

I did a simple integer update performance test. SQLite did only 15 updates per second while PostgreSQL did 1500 updates per second. The number with the SQLite case seems to be normal. The FAQ in...

Why is memmove faster than memcpy?

I am investigating performance hotspots in an application which spends 50% of its time in memmove(3). The application inserts millions of 4-byte integers into sorted arrays, and uses memmove to...

zip iterators asserting for equal length in python

I am looking for a nice way to zip several iterables raising an exception if the lengths of the iterables are not equal. In the case where the iterables are lists or have a len method this...

Bison value moving / efficiency

I'm working on constructing my parse data structure from bison's semantic values. One particular structure is of type std::vector<double>. I'm curious how the bison internals handle moving...

How to delay script/asset loading in Chrome Developer Tools

Is there any way to add a time delay to a script/asset loading in the Google Chrome Browser via the Chrome Developer Tools? Or to block a script loading entirely? The reason I want to do this is...

OSCP requests randomly appear in webpagetest.org results

When testing website performance with webpagetest.org, eventually some tests contain requests that should not have been requested by the selected...

Error while opening Jmeter Plugin Manager (jmeter-plugins-manager-0.16)

I have added the plugin manager jar(jmeter-plugins-manager-0.16) in lib/ext folder of Jmeter. I keep getting below error message when I try to open Plugin Manager through the options. Can someone...

How to throttle internet speed in Android

I wanted to test my Android app for user that have slow internet connection. Is there any way to do it? Usually I am using Chrome built in feature for doing this, but I can't find similar solution...

NoClassDefFoundError while running .jmx command line using lazerycode jmeter plugin

I am using lazerycode jmeter maven plugin to execute my jmeter tests. When I try to run my jmx file from the UI, it runs perfectly fine. but, when I try with to do with mvn, mvn clean install or...

Comparison of loading from different file formats in BigQuery

We currently load most of our data into BigQuery either via csv or directly via the streaming API. However, I was wondering if there were any benchmarks available (or maybe a Google engineer could...

~85.5% of native code when profiling with Jet Brain's dotTrace?

Whenever I do a session (both samplig and timeline), it says like up to 70-80 percent of entire exuction is occupied by native code. It seems kind of suspicious, not quite sure whether I got a...

why I enabled Metal API but my Coreml custom layer still run on CPU

I am really new to Coreml and Metal. Now I am working on a project testing performance of Core Ml model. I implemented a CNN model based on tensorflow and convert this model to .mlmodel using...

Python Codility Frog River One time complexity

So this is another approach to probably well-known codility platform, task about frog crossing the river. And sorry if this question is asked in bad manner, this is my first post here. The goal...

Docker Alpine and perf not getting along in docker container

First things first: Alpine Version 3.9.0 perf[from:http://dl-cdn.alpinelinux.org/alpine/edge/testing] 4.18.13 Docker 18.09.3 build 774a1f4 My Dockerfile FROM alpine:latest # Set the working...

Pandas multiindex creation performance

Performance tests for creating equal pd.MultiIndex using different class methods: import pandas as pd size_mult = 8 d1 = [1]*10**size_mult d2 = [2]*10**size_mult pd.__version__ '0.24.2' Namely...

How read data from csv file in locust performance test scripts?

I am trying to read the data from csv file that contails 1 row and 5 column using the following code def __init__(self): super(data, self).__init__() global data if (data...

How to pass Headers and x-www-form-urlencoded body in Autocannon

I'm trying to pass Headers and x-www-form-urlencoded body in Autocannon POST request, but my response is always: 0 2xx responses, 5 non 2xx responses Example from command line: autocannon -c 1 -a...

Use Jmeter desktop application as web app

As we know JMeter is desktop based application which will get launched in our OS and we can use it to do performance testing but what if I want to use it as web application rather than desktop...

Python selenium get "Developer Tools" →Network→Media logs

I am trying to programmatically do something that necessarily involves getting the "developer tools"→network→media logs. I will spare you the details, long story short, I need to visit...

Keras AttributeError: 'Sequential' object has no attribute 'predict_classes'

Im attempting to find model performance metrics (F1 score, accuracy, recall) following this guide...

Bubble sort slower with -O3 than -O2 with gcc

I made a bubble sort implementation in C, and was testing its performance when I noticed that the -O3 flag made it run even slower than no flags at all! Meanwhile -O2 was making it run a lot...

Why redis stream consumers should specify an individual name in the same consumer group?

The codes below show how I test the Redis stream functions. And I found that different processes with the same consumer name are competing to consume messages in the same stream. In my...

Avoid memory fragmentation when memory pools are a bad idea

I am developing a C++ application, where the program run endlessly, allocating and freeing millions of strings (char*) over time. And RAM usage is a serious consideration in the program. This...

Using different struct definitions to simulate public and private fields in C

I have been writing C for a decent amount of time, and obviously am aware that C does not have any support for explicit private and public fields within structs. However, I (believe) I have found...

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