We have written an application that performs small (22kB) writes to multiple files at once (one thread performing asynchronous queued writes to multiple locations on behalf of other threads) on the same local volume (RAID1). 99.9% of the writes are low-latency but occasionally (maybe every minute or two) we get one or two huge latency wr...
if i'm using jquery library with some plugins can i place all at bottom , just before </body> or it depends? are there some situations where library+plugin should place in not at end of not bottom? ...
Is there any tool can measure execution time for each function call and find out bottle neck for a given developing java j2se project? Thanks! ...
I need to rewrite about 4KB of data in reverse order, at bit level (last bit of last byte becoming first bit of first byte), as fast as possible. Are there any clever sniplets to do it? Rationale: The data is display contents of LCD screen in an embedded device that is usually positioned in a way that the screen is on your shoulders lev...
On a single line Regex if I want to capture all till the end of line.. Which of these will be better in terms of Performance? Regex r = new Regex(".+"); OR Regex r = new Regex("[^$]+$"); I haven't included the entire regex but I hope you get the idea. Are there any trade-offs or they both behave the same way? Thanks! ...
Suppose that I have a very large undirected, unweighted graph (starting at hundreds of millions of vertices, ~10 edges per vertex), non-distributed and processed by single thread only and that I want to do breadth-first searches on it. I expect them to be I/O-bound, thus I need a good-for-BFS disk page layout, disk space is not an issue....
Hey all, I wanted to know what is better performance-wise: to put the conditions in the JOIN? (x JOIN y on x.hi = y.hi AND ....) or maybe to put it under the WHERE, and leave the JOIN only with the crossing condition. thanks folks ...
Hi guys, I am about to begin developing a logging system for future implementation in a current PHP application to get load and usage statistics from a MYSQL database. The statistic will later on be used to get info about database calls per second, query times etc. Of course, this will only be used when the app is in testing stage, si...
I have a service that uses a fairly expensive object to create. I would like to improve the performance from call to call. When I remove the object and run a load test, like how many invocations I can do per second, I have a massive performance difference between to situations. Situation 1. I remove the expensive object: Invocations pe...
I am looking for an article about Disk Subsystem Stress for SQL Server. So I can do better capacity management ! I already know the basis but I am looking for an "how to" for dummies who wants to install and do some reporting and trending using Excel ! Thanks ...
Did you use Perf4J in your Java application to collect and analyze performance stats? What was the typical pattern (using log files, utilities, UI, JMX, etc.)? Did you use annotations and AOP-based features? Did you use any JMX integration? How did you handle production configuration? Did you include performance stats views/rep...
Hi, i am developing a framework for creating efficient applications in all sizes. Applications consist of modules (application is a module too) and performance is important for me. I know there are existing frameworks for modularization etc. but i needed to implement my own. Although i overthought about performance of individual modules...
here is code + (SalesCollection*)sharedCollection { @synchronized(self) { if (sharedInstance == nil) { [[self alloc] init]; // assignment not done here } } return sharedInstance; } + (id)allocWithZone:(NSZone *)zone { @synchronized(self) { if (sharedInstance == nil) { sharedInstance = [super allocWithZone:z...
Does anyone know how to test? I'm on Windows XP? and Firefox , IE7 installed ...
Hi, I added some additional code to the Linux kernel (the scheduler) and now I would like to know what is the impact of this modification. For user processes I always used: clock_gettime(CLOCK_PROCESS_CPUTIME_ID, ...); Now I am wondering if there is a kernel-equivalent routine that I could use to do something similar. Many thanks ...
The current DB or our project has crossed over 40 GB this month and on an average it is growing monthly by around 3 GB. Now all the tables are best normalized and proper indexing has been used. But still as the size is growing it is taking more time to fire even basic queries like 'select count(1) from table'. So can u share some more po...
is anyone know how to determine the "weight" of each factor affecting the performance improvement? actually i'm on the way in bulding some kinda simply tool look a like yslow to analyze website performance. But i have problem in determining the score of each factor. I use these factor to be analyzed : - make fewer http req - minify js an...
I wonder if there is any wise way to rewrite the following query so that the indexes on columns get used by optimizer? Create Procedure select_Proc1 @Key1 int=0, @Key2 int=0 As BEGIN Select key3 From Or_Table Where (@key1 =0 OR Key1 =@Key1) AND (@key2 =0 OR Key2 =@Key2) END GO Even though columns in the W...
I have a system to which I must apply load for the purpose of performance testing. Some of the load can be created via LoadRunner over HTTP. However in order to generate realistic load for the system I also need to simulate users using a command line tool which uses a non HTTP protocol* to talk to the server. * edit: actually it is HTT...
I want to time how long it takes the server to build a MediaWiki article. That is, the start time will be as close as possible to the time the server receives the request (not the time the client issues request). The end time will be when the server sends the page (again, not when the client receives the page). Is there any Apache fun...