In Code Complete 2 (page 601 and 602) there is a table of "Cost of Common Operations". The baseline operation integer assignment is given a value 1 and then the relative time for common operations is listed for Java and C++. For example: C++ Java Integer assignment 1 1...
I'm testing my simple OpenGL ES implementation (a 2D game) on the iPhone and I notice a high render utilization while using the profiler. These are the facts: I'm displaying only one preloaded large texture (512x512 pixels) at 60fps and the render utilization is around 40%. My texture is blended using GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALP...
I have seen that sometimes the performance of LINQ to Objects queries can be improved significantly if they forced to execute immediately by using .ToArray(), but can't quite understand why. For example, in the sample below, the execution of the function Deferred() is much slower than the function Immediate(), and grows exponentially wit...
We have an enterprise java application(ear - few ejb's and a webapp) deployed on to weblogic 10 and using Sun java 5. The response time , CPU and memory usage is fine under few users of load but if we increase the concurrent users to >100 we see huge CPU spikes after some time (for eg:- load test with 100 users, the CPU goes to high afte...
I'd like to know how many I/O operations (iops) does it take to create an empty file. I am interested in linux and GFS file system, however other file systems information is also very welcome. Suggestions how to accurately measure this would be also very welcome. Real scenario (requested by answers): Linux GFS file system (if you can...
How does performance for reading/adding values from/to Dictionary(Of String, SomeReferenceType) depend on the number of records already entered? I mean, does time increase as O(1), O(log n), O(n) when n goes to be large, or in some other way? Dim index As New Dictionary(Of String, SomeReferenceType) ' N entries added in a loop ' ... D...
I have a web application, backed by a SQL Server database, which was working fine till yesterday. Now I have performance issues with that application. How do I know whether it is an application issue or database issue or hardware issue? Can anyone help guide me through a step by step procedure of basic troubleshooting to find out whethe...
My PyQt application that uses matplotlib takes several seconds to load for the first time, even on a fast machine (the second load time is much shorter as the DLLs are kept in memory by Windows). I'm wondering whether it's feasible to show a splash screen while the matplotlib library is being loaded. Where does the actual loading take p...
Does anyone have an experience with pure AspectJ load time weaving in production systems (mostly interesting Tomcat related activities)? I'm slightly worrying regarding memory footprint and cpu overhead. ...
Suppose I have table in my DB schema called TEST with fields (id, name, address, phone, comments). Now, I know that I'm going to perform a large set of different queries for that table, therefore my question is next, when and why I shall create indexes like ID_NAME_INDX (index for id and name) and when it's more efficient to create separ...
I wonder if in my program I have only 1 thread, can I write it so that the Quad core or i7 can actually make use of the different cores? Usually when i write programs on a Quad core computer, the CPU usage will only go to about 25%, and the work seems to be divided among the 4 cores, as the Task Manager shows. (the programs i wrote usu...
I've now saved a bit of money for the hardware upgrade. What I'd like to know, which is the easiest way to measure which part of hardware is the bottleneck for compiling and should be upgraded? Are there any clever techniques I could use? I've looked into perfmon, but it has too many counters and isn't very helpful without exact knowled...
I remember reading quite a while ago that with() has some serious performance impacts in JavaScript due to its possibly non-deterministic change to the scope stack. I am having difficulty finding any recent discussion of this. Is this still true? ...
We have a system that makes calls to a web service across a proxy. This is coded in C#, using HttpWebRequest. We've had problems with the speed of these calls for a long time, and I'd been trying to track it down. An unrelated conversation led to one of the operations guys to mention that the port we had been going over used firewall sof...
class ApplicationContext{ private final NetworkObject networkObject = new networkObject(); public ApplicationContext(){ networkObject.setHost("host"); networkObject.setParams("param"); } public searchObjects(ObjectType objType){ networkObject.doSearch(buildQuery(objType)); } } class NetworkObjec...
I am about to begin reading tons of binary files, each with 1000 or more records. New files are added constantly so I'm writing a Windows service to monitor the directories and process new files as they are received. The files were created with a c++ program. I've recreated the struct definitions in c# and can read the data fine, but I'm...
This is a follow up to a recent post I've seen which suggests that PHP performance is poor: "PHP. IS. ALWAYS. THE. BOTTLENECK. My server farms, let me show you them! PHP Overall Performance" followed by: "PHP performance is frickin' abysmal. I am basing this on my experience with OpenX (on Linux) and WordPress (on win64)." Can we get...
Hi Experts, I have a requirement where I have to select around 60 million plus records from database. Once I have all records in ResultSet then I have to formate some columns as per the client requirement(date format and number format) and then I have to write all records in a file(secondary memory). Currently I am selecting records o...
What is the throughput of Google File System? ...
I wish to create a daily report on how my mysql server perform on the day. But it seems like mysql only stores aggregate data since uptime. One way is to generate a report and then do a mysql restart (or do a FLUSH STATUS). Any other suggestions to do the same? ...