Server virtualization is a big thing these days, so I'm tasked at work to install some of our software on a virtualized server and see what happens. Long story short: a rsync transfer promptly brings the virtualized server to its knees. The virtualization host is a beefy machine with no other load; I don't think this should be happening....
I'm working on a loosely coupled cluster for some data processing. The network code and processing code is in place, but we are evaluating different methodologies in our approach. Right now, as we should be, we are I/O bound on performance issues, and we're trying to decrease that bottleneck. Obviously, faster switches like Infiniband wo...
This question pertains to Ruby on Rails and PHP. When looking for a VPS host for a web application (haven't decided which of the 2 languages to write it in yet), what should I take into consideration more? Memory or CPU? I know that you need a fair balance of both, but which wall will I run into first? I'm sure it depends on the type o...
I was wondering if anyone can compare/contrast the differences between frontend, backend, and middleware ("middle-end"?) succinctly. Are there cases where they overlap? Are there cases where they MUST overlap, and frontend/backend cannot be separated? In terms of bottlenecks, which end is associated with which type of bottlenecks? ...
I have two test computers networked together. One has a gigabit ethernet, the other a 10 megabit. Theoretically, data trasferred between the two should reach about 1megabytes p/s. Now im using a PHP script to read data from one host to another using fread. Both reading file and file to be read are chmod 777. Both computers are runnin...
I ended up creating my own HTML class, mainly to keep all our output consistent. The code is below. <?php /** * A class to generate html tags * @author Glen Solsberry */ class HTML { private $isOpen; /** * holds all information about tags * @var $tags array */ private $tags; private $current_tag = 0;...
I've been hearing things about NoSQL and that it may eventually become the replacement for SQL DB storage methods due to the fact that DB interaction is often a bottle neck for speed on the web. So I just have a few questions: What exactly is it? How does it work? Why would it be better than using a SQL Database? And how much better i...
What is the most common performance bottleneck that is not caused by the database structure? ...
Hi, I'm using Firebird and created a table, called EVENTS. The columns are: id (INT) | name (VARCHAR) | category (INT) | website (VARCHAR) | lat (DOUBLE) | lon (DOUBLE) Now a user wants to search for events in a certain radius around him, but entered only two or three letters of his home city. So we've got - lets say - 200 possible c...
I have a performance bottleneck on a DataView.Sort. The code is below. /// <summary> /// Filters the data table and returns a new data table with only the filtered rows. /// </summary> /// <param name="dtInput">The dt input.</param> /// <param name="filterExpression">The filter expression.</param> /// <returns><...
I'm involved with a project using DotNetNuke version 05.01.04 Community Edition. We are building our new Intranet using it, but performance is terrible. We have five people adding pages and content to it and every 15-30 seconds they experience a pause of 10 seconds or longer before the system continues and the next screens loads. The s...
I'm working on a project which generates a very large number of sequential text strings, in a very tight loop. My application makes heavy use of SIMD instruction set extensions like SSE and MMX, in other parts of the program, but the key generator is plain C++. The way my key generator works is I have a keyGenerator class, which holds ...
I have a custom application which has a bunch of files open. I can see the file handles open by a process using "lsof" and I can see the files being accessed using "watch -d 'ls -alh'" and watching the mtime/ctime. However, I would like to see the rate of data that is being read/written to these files. IE: I need to determine if one file...
Hey, I have a Java desktop application I wrote, and I would like a recommendation about a monitoring application that can spot bottlenecks in the code and real time memory consumptions. As I was developing for J2Me, the WTK then, had a memory monitor, and I found it really useful, I would like to know which monitoring program you think...
I am trying to find the bottleneck of a multithreaded service. I used ab with -c 100 and observed TPS around 350. The question is the peak CPU usage is 70%, memory is 10%. So it looks like it's not cpu or memory bound. It's not doing disk or network I/O. How do I determine what the bottleneck is? ...
I'm sending a very large string from one application to another on localhost using sockets in python. Small strings move instantly, but large strings seem to take a while longer (I say large, but I'm talking maybe a MB or two at the very most). Enough that I have to sit and wait a few seconds after I do something in one app before it sh...
I have a J2EE project running on JBoss, with a maximum heap size of 2048m, which is giving strange results under load testing. I've benchmarked the heap and cpu usage and received the following results (series 1 is heap usage, series 2 is cpu usage): It seems as if the heap is being used properly and getting garbage collected properly...
There is an action in the admin section of a client's site, say Admin::Analytics (that I did not build but have to maintain) that compiles site usage analytics by performing a couple dozen, rather intensive database queries. This functionality has always been a bottleneck to application performance whenever the analytics report is being...
Hello, I have an .Net app and it runs fast through about 2000 records that starts to go really slow. I'm trying to find the bottleneck and I was wondering if there is a good, possibly free but it doesn't have to be, tool or a way to find the bottleneck. I'm trying to find a list that isn't cleared out but I don't see it yet. I have VS ...
Hi everybody, we are struggling to find out what could be the asp.net application performance decrease when we pass from our staging server to our production server and we would like to hear from you to help us find the bottleneck. Our staging server is a Intel Core 2 Quad CPU Q8200 (2.33 GHz) with 4GB of RAM, Windows Server 2003 R2 SP2...