When you have a multiplayer game where the server is receiving movement (location) information from the client, you want to verify this information as an anti-cheating measure. This can be done like this: maxPlayerSpeed = 300; // = 300 pixels every 1 second if ((1000 / (getTime() - oldTimestamp) * (newPosX - oldPosX)) > maxPlayerSpeed)...
I have a (java) application that runs in a low latency environment, it typically processes instructions in ~600micros (+/- 100). Naturally as we've moved further into the microsecond space the things you see that cost latency change and right now we've noticed that 2/3 of that time is spent in the allocation of the 2 core domain objects...
I want to have groups of 2-4 users playing a game that will require each user send to the others about 10-20 bytes of info every 1-3 seconds. So basically, low bandwidth usage, but low latency required. So I would like to have my own server/cluster of servers to support this communication, e.g. starting with 1000 users simultaneously and...
Don't know if anyone alrealy had this problem before but if yes, can you tell things we can try to do on server; We've gettin' something like 2 at 3 more times to execute an HTTP request on a hosted application comparing to the same local application (on debug). But if we trace between preinit and rederer, on host (release),we've gettin...
The C# application sends an email using System.Net.Mail.SmtpClient.Send The application's log file shows that the Send method succeeded at 11:39 When I open the email in Outlook and do File|Properties, it shows Sent: 11:39 AM Received: 11:41 AM If I go to View|Options , the headers show: Received: from XXX by YYY with Microsoft SMTPSVC ...
I'm working on enabling facebook connect with my website, and it seems to work pretty good so far. However, loading the facebook api library on every page of my site is bogging it way down. All the other php classes that I'm using compile in well under 1 second, but I'm seeing serve times ranging from 3 - 20 seconds just to get the faceb...
I use quite a lot of Dojo, but to date I've only used if by including from a CDN such as AOL/Google. Are there advantages to hosting a copy of Dojo rather than using it via a CDN? I don't have much need to alter the code base, but I imagine there are other advantages/disadvantages? ...
I am uploading data from Excel to SQL Server using the following structure: Private Sub ado_upload() Dim objConnection As New ADODB.Connection Dim objCommand As New ADODB.Command Dim strSQL As String Dim strDSN As String Dim intCounter As Integer strDSN = "provider=SQLOLEDB;" _ & "server=<server>;" _ & ...
Imagine you have many clustered servers, across many hosts, in a heterogeneous network environment, such that the connections between servers may have wildly varying latencies and bandwidth. You want to build a map of the connections between servers my transferring data between them. Of course, this map may become stale over time as th...
We have a low latency trading system (feed handlers, analytics, order entry) written in Java. It uses TCP and UDP extensively, it does not use Infiniband or other non-standard networking. Can anyone comment on the tradeoffs of various OSes or OS configurations to deploy this system? While throughput is obviously important to keep up wi...
Hi! in this document: http://infocenter.arm.com/help/topic/com.arm.doc.ddi0301g/DDI0301G_arm1176jzfs_r0p7_trm.pdf on page 21-25 (pdf page 875) the througput and latency timings are given for the assembly instructions of the VFP unit. Are those numbers independant of vectorsize? 1: let's take FMULS which has throughput of 1 and latenc...
I am writing a web service in Java which needs to handle a large number of requests / second. The general flow will be: Web service receives a request from client Returns a 'keep polling me' response to client Calls another web service (or services), and waits for them to respond (with a timeout) Client polls our web service, until it ...
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...
Hey all, I have a few questions about configuring a router to achieve low-latency, high speed throughput on a local area network that is not connected to the network. I've read up on some stuff, but thought I would solicit some opinions here on what I've found and what I want to know.... Turn off SSID broadcast - it produces extraneous...
Right now I'm trying to make a mmorpg for the iPhone. I have it set up so that the iPhone requests for the player positions several times a second. How it does this is that the client sends a request using asynchronous NSURLConnection to a php page that loads the positions from a mysql database and returns it in json. However, it takes a...
Hello, I have written an HTTP proxy that does some stuff that's not relevant here, but it is increasing the client's time-to-serve by a huge amount (600us without proxy vs 60000us with it). I think I have found where the bulk of that time is coming from - between my proxy finishing sending back to the client and the client finishing rece...
We make heavy use of multicasting messaging across many Linux servers on a LAN. We are seeing a lot of delays. We basically send an enormous number of small packages. We are more concerned with latency than throughput. The machines are all modern, multi-core (at least four, generally eight, 16 if you count hyperthreading) machines, a...
Hello All. I tried to send/receive data by using TcpClient. I did two experiments and found something interesting. I setup the TcpListener in a server in Japan and the TcpClient in UK. I kept sending 500 bytes to the TcpListener and when TcpListener sends 10KB back to the TcpClient. I kept this send/receive looping for 500 times in eac...
What is the simplest way to log the response-time for a restlet-based webservice? I want to make sure that our webservice has a reasonable response time. So I want to be able to keep an eye on response times, and do something about the requests that take too long. The closest thing I could find is this recipe: http://www.naviquan.com/b...
I'm playing some notes at regular intervals. Each one is delayed by a random number of milliseconds, creating a jarring irregular effect. How do I fix it? Note: I'm OK with some latency, just as long as it's consistent. Answers of the type "implement your own small SoundManager2 replacement, optimized for timing-sensitive playback" are...