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  • M2M Solutions: The Move to Value Creation and the Internet of Things

    - by Javier Puerta
    There's a new Oracle-sponsored report available around big data, specifically machine to machine data (there will probably be more growth in m2m data than human-generated stuff like social media). Forbes published an article, Big Data Set to Explode as 40 Billion New Devices Connect to Internet, which references the report. Login to Download the M2M Solutions Report Good reading!

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  • What's Happening in Business Analytics at OpenWorld 2012?

    - by jmorourke
    Oracle OpenWorld 2012 is rapidly approaching on September 30th when we take over the city of San Francisco for five days.  The Business Analytics this year is our strongest ever with over 150 EPM, BI, Analytics and Data Warehousing sessions delivered by Oracle, our customers and partners.  We’ll also have Hands-On Labs, 20 demo pods dedicated to Business Analytics products, and over 30 partners exhibiting their solutions.  So what’s hot in the Business Analytics program at OpenWorld?  Here are some of the “can’t miss” sessions at this year’s conference: The EPM and BI general sessions, led by SVP of Product Development Balaji Yelamanchili will highlight what’s new provide a view into Oracle’s EPM, BI and Analytics strategies.  Both sessions are scheduled on Monday, October 1st. Thursday Keynote:  See More, Act Faster:  Oracle Business Analytics, led by Oracle President Mark Hurd, will provide a view into Oracle’s strategy for Business Analytics, especially engineered systems designed to provide extreme performance for the most rigorous analytic tasks. Superfast Business Intelligence with Oracle Exalytics.  Hear about various business intelligence scenarios in which Oracle Exalytics provides exemplary value—from operational reporting and prepackaged applications to analytics on unstructured data. Turn Insights into Real-Time Actions with Oracle Business Intelligence Mobile.  Learn how Oracle Business Intelligence Mobile enables organizations to deliver relevant information and turn insight into real-time action, no matter where employees are located. Empowering the Business User: Introduction to Oracle Endeca Information Discovery.  Find out how you can find fast answers to the new questions that confront your business every day, while avoiding the confusion and inconsistencies brought about by spreadsheets and desktop tools. Big Data:  The Big Story.  Learn how to harness big data, your existing data, and predictive analytics to make better decisions in an environment of rapid shifts in behavior and instant feedback.  Learn about the technologies that constitute a big data architecture, how to leverage and implement advanced analytics for real-time decisions, and the tools needed to know the unknown. Planning at the Speed of Business with Oracle Exalytics.  Learn how Oracle Hyperion Planning leverages the power of Oracle Exalytics to do planning faster, with more detail and more users than ever. For more details on these and other Business Analytics sessions at OpenWorld, download the Focus On Business Analytics program guide at:  http://www.oracle.com/openworld/focus-on/index.html We look forward to seeing you in San Francisco!

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  • How do I produce "enjoyably" random, as opposed to pseudo-random?

    - by Hilton Campbell
    I'm making a game which presents a number of different kinds of puzzles in sequence. I choose each puzzle with a pseudorandom number. For each puzzle, there are a number of variations. I choose the variation with another pseudorandom number. And so on. The thing is, while this produces near-true randomness, this isn't what the player really wants. The player typically wants what they perceive to be and identify as random, but only if it doesn't tend to repeat puzzles. So, not really random. Just unpredictable. Giving it some thought, I can imagine hacky ways of doing it. For example, temporarily eliminating the most recent N choices from the set of possibilities when selecting a new choice. Or assigning every choice an equal probability, reducing a choice's probability to zero on selection, and then increasing all probabilities slowly with each selection. I assume there's an established way of doing this, but I just don't know the terminology so I can't find it. Anyone know? Or has anyone solved this in a pleasing way?

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  • How can I fix a date that changes by 4 years and 1 day when pasted between Excel workbooks

    - by lcbrevard
    In Excel dates are represented internally by a floating point number where the integer part is the number of days since "some date" and the fractional part is how far into that day (hence the time). You can see this if you change the format of a date - like 4/10/2009 to a number 39905. But when pasting a date between two different workbooks the date shifts by 4 years and one day!!! In other words "some date" is different between the two workbooks. In one workbook the number 0.0 represents 1/0/1900 and in the other 0.0 represents 1/1/1904. Where is this set and is it controllable? Or does this represent a corrupted file? These workbooks where originally from Excel 2000 but have been worked on now in Excel 2007 and Excel 2003. I can demonstrate the problem between the two workbook files in both 2003 and 2010. The exact history of when they were created or what versions of Excel have been used on each is unknown.

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  • Clustering Strings on the basis of Common Substrings

    - by pk188
    I have around 10000+ strings and have to identify and group all the strings which looks similar(I base the similarity on the number of common words between any two give strings). The more number of common words, more similar the strings would be. For instance: How to make another layer from an existing layer Unable to edit data on the network drive Existing layers in the desktop Assistance with network drive In this case, the strings 1 and 3 are similar with common words Existing, Layer and 2 and 4 are similar with common words Network Drive(eliminating stop word) The steps I'm following are: Iterate through the data set Do a row by row comparison Find the common words between the strings Form a cluster where number of common words is greater than or equal to 2(eliminating stop words) If number of common words<2, put the string in a new cluster. Assign the rows either to the existing clusters or form a new one depending upon the common words Continue until all the strings are processed I am implementing the project in C#, and have got till step 3. However, I'm not sure how to proceed with the clustering. I have researched a lot about string clustering but could not find any solution that fits my problem. Your inputs would be highly appreciated.

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  • Algorithm for grouping friends at the cinema [closed]

    - by Tim Skauge
    I got a brain teaser for you - it's not as simple as it sounds so please read and try to solve the issue. Before you ask if it's homework - it's not! I just wish to see if there's an elegant way of solving this. Here's the issue: X-number of friends want's to go to the cinema and wish to be seated in the best available groups. Best case is that everyone sits together and worst case is that everyone sits alone. Fewer groups are preferred over more groups. Sitting alone is least preferred. Input is the number of people going to the cinema and output should be an array of integer arrays that contains: Ordered combinations (most preferred are first) Number of people in each group Below are some examples of number of people going to the cinema and a list of preferred combinations these people can be seated: 1 person: 1 2 persons: 2, 1+1 3 persons: 3, 2+1, 1+1+1 4 persons: 4, 2+2, 3+1, 2+1+1, 1+1+1+1 5 persons: 5, 3+2, 4+1, 2+2+1, 3+1+1, 2+1+1+1, 1+1+1+1+1 6 persons: 6, 3+3, 4+2, 2+2+2, 5+1, 3+2+1, 2+2+1+1, 2+1+1+1+1, 1+1+1+1+1+1 Example with more than 7 persons explodes in combinations but I think you get the point by now. Question is: What does an algorithm look like that solves this problem? My language by choice is C# so if you could give an answer in C# it would be fantastic!

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  • QR Codes and Short Links - Please Take A Look [closed]

    - by Joe Turner
    I'm looking for a way to create a QR Code and a shortened link when a form is submitted. I have the QR Code bit, but the link is too long for me and the QR Code looks scary and complicated. The way it works is; the user types in (in this instance) a contract number. Then, a folder is created on the server of that contract number. (www.mysite.com/QR/$contractnumber). Then, using PHP again, I create a QR Code through Google because I know that every QR code will be linking to the same place, just a different ending of the link. The only bit that changes is the $POST... I was wondering if there was a way to shorten the link before it goes to Google? It would have to be through php. The user enters the contact number in the form, then that number(usually around 5/6 digits) will be entered into a already existing command? I'm not an expert in anything, I just know some really random snippets of code... And HTML and CSS, of course. Any help would be appreciated and judging by the few days I have been searching this, I think it might help a few people in the future. I would also like to confirm that the solution can't be one of this visual URLShorteners. If it is, it just needs to be the back-end of it, built into a existing form and QR Generator. Simple?

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  • Shell script to read value from a file and compare it to another one

    - by maneeshshetty
    I have a C program which puts one unique value inside a test file (it would be a two digit number). Now I want to run a shell script to read that number and then compare with my required number (e.g. 40). The comparison should deliver "equal to" or "greater". For example: The output of the C program is written into the file called c.txt with the value 36, and I want to compare it with the number 40. So I want that comparison to be "equal to" or "greater" and then echo the value "equal" or "greater".

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  • On Developing Web Services with Global State

    - by user74418
    I'm new to web programming. I'm more experienced and comfortable with client-side code. Recently, I've been dabbling in web programming through Python's Google App Engine. I ran into some difficulty while trying to write some simple apps for the purposes of learning, mainly involving how to maintain some kind of consistent universally-accessible state for the application. I tried to write a simple queueing management system, the kind you would expect to be used in a small clinic, or at a cafeteria. Typically, this is done with hardware. You take a number from a ticketing machine, and when your number is displayed or called you approach the counter for service. Alternatively, you could be given a small pager, which will beep or vibrate when it is your turn to receive service. The former is somewhat better in that you have an idea of how many people are still ahead of you in the queue. In this situation, the global state is the last number in queue, which needs to be updated whenever a request is made to the server. I'm not sure how to best to store and maintain this value in a GAE context. The solution I thought of was to keep the value in the Datastore, attempt to query it during a ticket request, update the value, and then re-store it with put. My problem is that I haven't figured out how to lock the resource so that other requests do not check the value while it is in the middle of being updated. I am concerned that I may end up ticket requests that have the same queue number. Also, the whole solution feels awkward to me. I was wondering if there was a more natural way to accomplish this without having to go through the Datastore. Can anyone with more experience in this domain provide some advice on how to approach the design of the above application?

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  • Are the other organizations such as BSA that a small company can join?

    - by Saariko
    I am looking for other associations such as BSA. Setting aside the long debate about : should/can a software be protected?! I am currently actively looking for other, local, intentaional or even rgional groups/organizations that a small software company wants to join. I mark : small, since the BSA fees are expensive. please don't open the debate: if you are not big enough to pay the fee, than you are not big enough to join the __. Thank you

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  • The Important Relationship Between SEO and Google - Google Dominates

    Let's face it when it comes to SEO, Google (commonly known as the Big G) has its final say. After all, when it comes to searching some information online people would always go for Google. All they do is key-in the keyword on the search box and click the search button. Few seconds after, results will be given. Google is a big company and has been the subject of a lot of experiments when it comes to SEO.

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  • How does the internet protocol handle network card numbers?

    - by Giorgio
    I know that data packets sent over the internet carry the source and destination IP address, so that the protocol can route the data to the correct destination and keep track of the source address of the packet. But what about the network card address? As far as I know, each network card has a unique identification number. Is this also transmitted with a TCP/IP packet? And when a packet is received at its destination, how is the IP address mapped to a network card number? In other words. On the sender part: does the sender store the sender network card number in the IP packets that it is sending? On the receiver part: which component maps the IP address to the receiver's network card number when a packet is received? E.g., in a home network, does the modem / router map the destination IP address of an incoming packet to a network card number and deliver the packet directly to that network card? A link to documentation on these topics would be of great help.

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  • How can I avoid Excel reformatting the scientific notation numbers I enter?

    - by Diomidis Spinellis
    When I enter a number like 8230e12 into a Microsoft Excel 2000 cell, Excel changes the number I entered into 8230000000000000. (This is what I get when I press F2 to edit the cell's contents, not what Excel displays in the cell). How can I force Excel to keep the data in the format I typed it and still be able to format it and use it as a number? Displaying the cell in scientific notation is not enough, because the exponent is not the same one as the one I typed.

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  • RPGMakerVX - Changing item_max?

    - by rackemup420
    I've been working on a game for awhile and I am developing it with RPG Maker VX. I came to a point where I needed to... I guess for lack of better explanation... Limit the key items to just 1. So I started looking through my scripts and found (in Game_Party): #-------------------------------------------------------------------------- # * Get Maximum Number of Items Possessed #-------------------------------------------------------------------------- def max_item_number(item) return 99 end and added below it: #-------------------------------------------------------------------------- # * Get Maximum Number of Key Items Possessed #-------------------------------------------------------------------------- def max_key_item_number(item) return 1 end and right below that is: #-------------------------------------------------------------------------- # * Determine if Maximum Number of Items Are Possessed #-------------------------------------------------------------------------- def item_max?(item) item_number(item) >= max_item_number(item) end So I changed the last one too: #-------------------------------------------------------------------------- # * Determine if Maximum Number of Items Are Possessed #-------------------------------------------------------------------------- def item_max?(item) if key_item? == true item_number(item) >= max_key_item_number(item) end if key_item? == false item_number(item) >= max_item_number(item) end end Now this seemed to not affect anything (that I could tell). I tested it and its still the same as before I touched anything. I am new to developing games and relatively new to scripting for them. Is this approach even close to what I want to do? Any help is greatly apprecieated!

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  • Python - pyparsing unicode characters

    - by mgj
    Hi..:) I tried using w = Word(printables), but it isn't working. How should I give the spec for this. 'w' is meant to process Hindi characters (UTF-8) The code specifies the grammar and parses accordingly. 671.assess :: ????? ::2 x=number + "." + src + "::" + w + "::" + number + "." + number If there is only english characters it is working so the code is correct for the ascii format but the code is not working for the unicode format. I mean that the code works when we have something of the form 671.assess :: ahsaas ::2 i.e. it parses words in the english format, but I am not sure how to parse and then print characters in the unicode format. I need this for English Hindi word alignment for purpose. The python code looks like this: # -*- coding: utf-8 -*- from pyparsing import Literal, Word, Optional, nums, alphas, ZeroOrMore, printables , Group , alphas8bit , # grammar src = Word(printables) trans = Word(printables) number = Word(nums) x=number + "." + src + "::" + trans + "::" + number + "." + number #parsing for eng-dict efiledata = open('b1aop_or_not_word.txt').read() eresults = x.parseString(efiledata) edict1 = {} edict2 = {} counter=0 xx=list() for result in eresults: trans=""#translation string ew=""#english word xx=result[0] ew=xx[2] trans=xx[4] edict1 = { ew:trans } edict2.update(edict1) print len(edict2) #no of entries in the english dictionary print "edict2 has been created" print "english dictionary" , edict2 #parsing for hin-dict hfiledata = open('b1aop_or_not_word.txt').read() hresults = x.scanString(hfiledata) hdict1 = {} hdict2 = {} counter=0 for result in hresults: trans=""#translation string hw=""#hin word xx=result[0] hw=xx[2] trans=xx[4] #print trans hdict1 = { trans:hw } hdict2.update(hdict1) print len(hdict2) #no of entries in the hindi dictionary print"hdict2 has been created" print "hindi dictionary" , hdict2 ''' ####################################################################################################################### def translate(d, ow, hinlist): if ow in d.keys():#ow=old word d=dict print ow , "exists in the dictionary keys" transes = d[ow] transes = transes.split() print "possible transes for" , ow , " = ", transes for word in transes: if word in hinlist: print "trans for" , ow , " = ", word return word return None else: print ow , "absent" return None f = open('bidir','w') #lines = ["'\ #5# 10 # and better performance in business in turn benefits consumers . # 0 0 0 0 0 0 0 0 0 0 \ #5# 11 # vHyaapaar mEmn bEhtr kaam upbhOkHtaaomn kE lIe laabhpHrdd hOtaa hAI . # 0 0 0 0 0 0 0 0 0 0 0 \ #'"] data=open('bi_full_2','rb').read() lines = data.split('!@#$%') loc=0 for line in lines: eng, hin = [subline.split(' # ') for subline in line.strip('\n').split('\n')] for transdict, source, dest in [(edict2, eng, hin), (hdict2, hin, eng)]: sourcethings = source[2].split() for word in source[1].split(): tl = dest[1].split() otherword = translate(transdict, word, tl) loc = source[1].split().index(word) if otherword is not None: otherword = otherword.strip() print word, ' <-> ', otherword, 'meaning=good' if otherword in dest[1].split(): print word, ' <-> ', otherword, 'trans=good' sourcethings[loc] = str( dest[1].split().index(otherword) + 1) source[2] = ' '.join(sourcethings) eng = ' # '.join(eng) hin = ' # '.join(hin) f.write(eng+'\n'+hin+'\n\n\n') f.close() ''' if an example input sentence for the source file is: 1# 5 # modern markets : confident consumers # 0 0 0 0 0 1# 6 # AddhUnIk baajaar : AshHvsHt upbhOkHtaa . # 0 0 0 0 0 0 !@#$% the ouptut would look like this :- 1# 5 # modern markets : confident consumers # 1 2 3 4 5 1# 6 # AddhUnIk baajaar : AshHvsHt upbhOkHtaa . # 1 2 3 4 5 0 !@#$% Output Explanation:- This achieves bidirectional alignment. It means the first word of english 'modern' maps to the first word of hindi 'AddhUnIk' and vice versa. Here even characters are take as words as they also are an integral part of bidirectional mapping. Thus if you observe the hindi WORD '.' has a null alignment and it maps to nothing with respect to the English sentence as it doesn't have a full stop. The 3rd line int the output basically represents a delimiter when we are working for a number of sentences for which your trying to achieve bidirectional mapping. What modification should i make for it to work if the I have the hindi sentences in Unicode(UTF-8) format.

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  • Qt: TableWidget's ItemAt() acting weirdly

    - by emredog
    Hi, i'm working on a windows application, where in a dialog i query some data from Postgres, and manually show the output in a table widget. m_ui->tableWidget->setRowCount(joinedData.count()); for(int i=0; i<joinedData.count(); i++) //for each row { m_ui->tableWidget->setItem(i, 0, new QTableWidgetItem(joinedData[i].bobin.referenceNumber)); m_ui->tableWidget->setItem(i, 1, new QTableWidgetItem(QString::number(joinedData[i].bobin.width))); m_ui->tableWidget->setItem(i, 2, new QTableWidgetItem(QString::number(joinedData[i].tolerance.getHole()))); m_ui->tableWidget->setItem(i, 3, new QTableWidgetItem(QString::number(joinedData[i].tolerance.getLessThanZeroFive()))); m_ui->tableWidget->setItem(i, 4, new QTableWidgetItem(QString::number(joinedData[i].tolerance.getZeroFive_to_zeroSeven()))); m_ui->tableWidget->setItem(i, 5, new QTableWidgetItem(QString::number(joinedData[i].tolerance.getZeroFive_to_zeroSeven_repetitive()))); m_ui->tableWidget->setItem(i, 6, new QTableWidgetItem(QString::number(joinedData[i].tolerance.getZeroSeven_to_Three()))); m_ui->tableWidget->setItem(i, 7, new QTableWidgetItem(QString::number(joinedData[i].tolerance.getThree_to_five()))); m_ui->tableWidget->setItem(i, 8, new QTableWidgetItem(QString::number(joinedData[i].tolerance.getMoreThanFive()))); } Also, based on row and column information, i paint some of these tablewidgetitems to some colors, but i don't think it's relevant. I reimplemented the QDialog's contextMenuEvent, to obtain the right clicked tableWidgetItem's row and column coordinates: void BobinFlanView::contextMenuEvent(QContextMenuEvent *event) { QMenu menu(m_ui->tableWidget); //standard actions menu.addAction(this->markInactiveAction); menu.addAction(this->markActiveAction); menu.addSeparator(); menu.addAction(this->exportAction); menu.addAction(this->exportAllAction); //obtain the rightClickedItem QTableWidgetItem* clickedItem = m_ui->tableWidget->itemAt(m_ui->tableWidget->mapFromGlobal(event->globalPos())); // if it's a colored one, add some more actions if (clickedItem && clickedItem->column()>1 && clickedItem->row()>0) { //this is a property, i'm keeping this for a later use this->lastRightClickedItem = clickedItem; //debug purpose: QMessageBox::information(this, "", QString("clickedItem = %1, %2").arg(clickedItem->row()).arg(clickedItem->column())); QMessageBox::information(this, "", QString("globalClick = %1, %2\ntransformedPos = %3, %4").arg(event->globalX()).arg(event->globalY()) .arg(m_ui->tableWidget->mapFromGlobal(event->globalPos()).x()).arg(m_ui->tableWidget->mapFromGlobal(event->globalPos()).y())); menu.addSeparator(); menu.addAction(this->changeSelectedToleranceToUygun); menu.addAction(this->changeSelectedToleranceToUyar); menu.addAction(this->changeSelectedToleranceToDurdurUyar); //... some other irrevelant 'enable/disable' activities menu.exec(event->globalPos()); } The problem is, when i right click on the same item i get the same global coordinates, but randomly different row-column information. For instance, the global pos is exactly 600,230 but row-column pair is randomly (5,3) and (4,3). I mean, what?! Also, when i click to an item from the last to rows (later than 13, i guess) will never go into condition "if (clickedItem && clickedItem-column()1 && clickedItem-row()0)", i think it's mainly because 'clickedItem' is null. I'll be more than glad to share any more information, or even the full cpp-h-ui trio in order to get help. Thanks a lot.

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  • C Language: Why I cannot transfer file from server to client?

    - by user275753
    I want to ask, why I cannot transfer file from server to client? When I start to send the file from server, the client side program will have problem. So, I spend some times to check the code, But I still cannot find out the problem Can anyone point out the problem for me? thanks a lot! [client side code] include include include include include include include define SA struct sockaddr define S_PORT 5678 define MAXLEN 1000 define true 1 void errexit(const char *format, ...) { va_list args; va_start(args, format); vfprintf(stderr, format, args); va_end(args); WSACleanup(); exit(1); } int main(int argc, char *argv []) { WSADATA wsadata; SOCKET sockfd; int number,message; char outbuff[MAXLEN],inbuff[MAXLEN]; char PWD_buffer[_MAX_PATH]; struct sockaddr_in servaddr; FILE *fp; int numbytes; char buf[2048]; if (WSAStartup(MAKEWORD(2,2), &wsadata) != 0) errexit("WSAStartup failed\n"); if (argc != 2) errexit("client IPaddress"); if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET ) errexit("socket error: error number %d\n", WSAGetLastError()); memset(&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_port = htons(S_PORT); if ( (servaddr.sin_addr.s_addr = inet_addr(argv[1])) == INADDR_NONE) errexit("inet_addr error: error number %d\n", WSAGetLastError()); if (connect(sockfd, (SA *) &servaddr, sizeof(servaddr)) == SOCKET_ERROR) errexit("connect error: error number %d\n", WSAGetLastError()); if ( (fp = fopen("C:\\users\\pc\\desktop\\COPY.c", "wb")) == NULL){ perror("fopen"); exit(1); } printf("Still NO PROBLEM!\n"); //Receive file from server while(1){ numbytes = read(sockfd, buf, sizeof(buf)); printf("read %d bytes, ", numbytes); if(numbytes == 0){ printf("\n"); break; } numbytes = fwrite(buf, sizeof(char), numbytes, fp); printf("fwrite %d bytes\n", numbytes); } fclose(fp); close(sockfd); return 0; } server side code include include include include include include include include define SA struct sockaddr define S_PORT 5678 define MAXLEN 1000 void errexit(const char *format, ...) { va_list args; va_start(args, format); vfprintf(stderr, format, args); va_end(args); WSACleanup(); exit(1); } int main(int argc, char *argv []) { WSADATA wsadata; SOCKET listenfd, connfd; int number, message, numbytes; int h, i, j, alen; int nread; struct sockaddr_in servaddr, cliaddr; FILE *in_file, *out_file, *fp; char buf[4096]; if (WSAStartup(MAKEWORD(2,2), &wsadata) != 0) errexit("WSAStartup failed\n"); listenfd = socket(AF_INET, SOCK_STREAM, 0); if (listenfd == INVALID_SOCKET) errexit("cannot create socket: error number %d\n", WSAGetLastError()); memset(&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = htonl(INADDR_ANY); servaddr.sin_port = htons(S_PORT); if (bind(listenfd, (SA *) &servaddr, sizeof(servaddr)) == SOCKET_ERROR) errexit("can't bind to port %d: error number %d\n", S_PORT, WSAGetLastError()); if (listen(listenfd, 5) == SOCKET_ERROR) errexit("can't listen on port %d: error number %d\n", S_PORT, WSAGetLastError()); alen = sizeof(SA); connfd = accept(listenfd, (SA *) &cliaddr, &alen); if (connfd == INVALID_SOCKET) errexit("accept failed: error number %d\n", WSAGetLastError()); printf("accept one client from %s!\n", inet_ntoa(cliaddr.sin_addr)); fp = fopen ("client.c", "rb"); // open file stored in server if (fp == NULL) { printf("\nfile NOT exist"); } //Sending file while(!feof(fp)){ numbytes = fread(buf, sizeof(char), sizeof(buf), fp); printf("fread %d bytes, ", numbytes); numbytes = write(connfd, buf, numbytes); printf("Sending %d bytes\n",numbytes); } fclose (fp); closesocket(listenfd); closesocket(connfd); return 0; }

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  • PHP Array issue - not looping through foreach...

    - by Homer_J
    Ok, Here is the code: function fetch_questions($page) { global $link; $proc = mysqli_prepare($link, "SELECT * FROM tquestions_cwh WHERE page = ?"); mysqli_stmt_bind_param($proc, "i", $page); mysqli_stmt_execute($proc); $rows = array(); stmt_bind_assoc($proc, $rowq); // loop through all result rows while ($proc->fetch()) { // print_r($rowq); $rows[]=$rowq; } mysqli_stmt_close($proc); mysqli_clean_connection($link); return($rows); } I then add this to a php variable, like so: $qs = fetch_questions($page); I then loop through is, like so: foreach($qs as $value){ echo "<tr>".$value['qnum']." is the questions number and the question text is ".$value['qtext'].". The page and q values are ".$value['page']." and ".$value['questions']." respectively.</tr>"; The output, however is this: 8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively.8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively.8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively.8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively.8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively.8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively.8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively.8 is the questions number and the question text is I know how what I do fits into my team's objectives. The page and q values are 1 and q8 respectively. Which is not what I want, for information purposes, the array using the print function looks like this: Array ( [0] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) [1] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) [2] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) [3] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) [4] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) [5] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) [6] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) [7] => Array ( [questions] => q8 [qnum] => 8 [qtext] => I know how what I do fits into my team's objectives [page] => 1 ) ) Clearly it's not looping through and displaying each row as it should...any advice? Homer.

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  • Box2D Joints in entity components system

    - by Johnmph
    I search a way to have Box2D joints in an entity component system, here is what i found : 1) Having the joints in Box2D/Body component as parameters, we have a joint array with an ID by joint and having in the other body component the same joint ID, like in this example : Entity1 - Box2D/Body component { Body => (body parameters), Joints => { Joint1 => (joint parameters), others joints... } } // Joint ID = Joint1 Entity2 - Box2D/Body component { Body => (body parameters), Joints => { Joint1 => (joint parameters), others joints... } } // Same joint ID than in Entity1 There are 3 problems with this solution : The first problem is the implementation of this solution, we must manage the joints ID to create joints and to know between which bodies they are connected. The second problem is the parameters of joint, where are they got ? on the Entity1 or Entity2 ? If they are the same parameters for the joint, there is no problem but if they are differents ? The third problem is that we can't limit number of bodies to 2 by joint (which is mandatory), a joint can only link 2 bodies, in this solution, nothing prevents to create more than 2 entities with for each a body component with the same joint ID, in this case, how we know the 2 bodies to joint and what to do with others bodies ? 2) Same solution than the first solution but by having entities ID instead of Joint ID, like in this example : Entity1 - Box2D/Body component { Body => (body parameters), Joints => { Entity2 => (joint parameters), others joints... } } Entity2 - Box2D/Body component { Body => (body parameters), Joints => { Entity1 => (joint parameters), others joints... } } With this solution, we fix the first problem of the first solution but we have always the two others problems. 3) Having a Box2D/Joint component which is inserted in the entities which contains the bodies to joint (we share the same joint component between entities with bodies to joint), like in this example : Entity1 - Box2D/Body component { Body => (body parameters) } - Box2D/Joint component { Joint => (Joint parameters) } // Shared, same as in Entity2 Entity2 - Box2D/Body component { Body => (body parameters) } - Box2D/Joint component { Joint => (joint parameters) } // Shared, same as in Entity1 There are 2 problems with this solution : The first problem is the same problem than in solution 1 and 2 : We can't limit number of bodies to 2 by joint (which is mandatory), a joint can only link 2 bodies, in this solution, nothing prevents to create more than 2 entities with for each a body component and the shared joint component, in this case, how we know the 2 bodies to joint and what to do with others bodies ? The second problem is that we can have only one joint by body because entity components system allows to have only one component of same type in an entity. So we can't put two Joint components in the same entity. 4) Having a Box2D/Joint component which is inserted in the entity which contains the first body component to joint and which has an entity ID parameter (this entity contains the second body to joint), like in this example : Entity1 - Box2D/Body component { Body => (body parameters) } - Box2D/Joint component { Entity2 => (Joint parameters) } // Entity2 is the entity ID which contains the other body to joint, the first body being in this entity Entity2 - Box2D/Body component { Body => (body parameters) } There are exactly the same problems that in the third solution, the only difference is that we can have two differents joints by entity instead of one (by putting one joint component in an entity and another joint component in another entity, each joint referencing to the other entity). 5) Having a Box2D/Joint component which take in parameter the two entities ID which contains the bodies to joint, this component can be inserted in any entity, like in this example : Entity1 - Box2D/Body component { Body => (body parameters) } Entity2 - Box2D/Body component { Body => (body parameters) } Entity3 - Box2D/Joint component { Joint => (Body1 => Entity1, Body2 => Entity2, others parameters of joint) } // Entity1 is the ID of the entity which have the first body to joint and Entity2 is the ID of the entity which have the second body to joint (This component can be in any entity, that doesn't matter) With this solution, we fix the problem of the body limitation by joint, we can only have two bodies per joint, which is correct. And we are not limited by number of joints per body, because we can create an another Box2D/Joint component, referencing to Entity1 and Entity2 and put this component in a new entity. The problem of this solution is : What happens if we change the Body1 or Body2 parameter of Joint component at runtime ? We need to add code to sync the Body1/Body2 parameters changes with the real joint object. 6) Same as solution 3 but in a better way : Having a Box2D/Joint component Box2D/Joint which is inserted in the entities which contains the bodies to joint, we share the same joint component between these entities BUT the difference is that we create a new entity to link the body component with the joint component, like in this example : Entity1 - Box2D/Body component { Body => (body parameters) } // Shared, same as in Entity3 Entity2 - Box2D/Body component { Body => (body parameters) } // Shared, same as in Entity4 Entity3 - Box2D/Body component { Body => (body parameters) } // Shared, same as in Entity1 - Box2D/Joint component { Joint => (joint parameters) } // Shared, same as in Entity4 Entity4 - Box2D/Body component { Body => (body parameters) } // Shared, same as in Entity2 - Box2D/Joint component { Joint => (joint parameters) } // Shared, same as in Entity3 With this solution, we fix the second problem of the solution 3, because we can create an Entity5 which will have the shared body component of Entity1 and an another joint component so we are no longer limited in the joint number per body. But the first problem of solution 3 remains, because we can't limit the number of entities which have the shared joint component. To resolve this problem, we can add a way to limit the number of share of a component, so for the Joint component, we limit the number of share to 2, because we can only joint 2 bodies per joint. This solution would be perfect because there is no need to add code to sync changes like in the solution 5 because we are notified by the entity components system when components / entities are added to/removed from the system. But there is a conception problem : How to know easily and quickly between which bodies the joint operates ? Because, there is no way to find easily an entity with a component instance. My question is : Which solution is the best ? Is there any other better solutions ? Sorry for the long text and my bad english.

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  • Code Camp 2011 – Summary

    - by hajan
    Waiting whole twelve months to come this year’s Code Camp 2011 event was something which all Microsoft technologies (and even non-Microsoft techs.) developers were doing in the past year. Last year’s success was enough big to be heard and to influence everything around our developer community and beyond. Code Camp 2011 was nothing else but a invincible success which will remain in our memory for a long time from now. Darko Milevski (president of MKDOT.NET UG and SharePoint MVP) said something interesting at the event keynote that up to now we were looking at the past by saying what we did… now we will focus on the future and how to develop our community more and more in the future days, weeks, months and I hope so for many years… Even though it was held only two days ago (26th of November 2011), I already feel the nostalgia for everything that happened there and for the excellent time we have spent all together. ORGANIZED BY ENTHUSIASTS AND EXPERTS Code Camp 2011 was organized by number of community enthusiasts and experts who have unselfishly contributed with all their free time to make the best of this event. The event was organized by a known community group called MKDOT.NET User Group, name of a user group which is known not only in Macedonia, but also in many countries abroad. Organization mainly consists of software developers, technical leaders, team leaders in several known companies in Macedonia, as well as Microsoft MVPs. SPEAKERS There were 24 speakers at five parallel tracks. At Code Camp 2011 we had two groups of speakers: Professional Experts in various technologies and Student Speakers. The new interesting thing here is the Student Speakers, which draw attention a lot, especially to other students who were interested to see what their colleagues are going to speak about and how do they use Microsoft technologies in different coding scenarios and practices, in different topics. From the rest of the professional speakers, there were 7 Microsoft MVPs: Two ASP.NET/IIS MVPs, Two C# MVPs, and One MVP in SharePoint, SQL Server and Exchange Server. I must say that besides the MVP Speakers, who definitely did a great job as always… there were other excellent speakers as well, which were speaking on various technologies, such as: Web Development, Windows Phone Development, XNA, Windows 8, Games Development, Entity Framework, Event-driven programming, SOLID, SQLCLR, T-SQL, e.t.c. SESSIONS There were 25 sessions mainly all related to Microsoft technologies, but ranging from Windows 8, WP7, ASP.NET till Games Development, XNA and Event-driven programming. Sessions were going in five parallel tracks named as Red, Yellow, Green, Blue and Student track. Five presentations in each track, each with level 300 or 400. More info MY SESSION (ASP.NET MVC Best Practices) I must say that from the big number of speaking engagements I have had, this was one of my best performances and definitely I have set new records of attendees at my sessions and probably overall. I spoke on topic ASP.NET MVC Best Practices, where I have shown tips, tricks, guidelines and best practices on what to use and what to avoid by developing with one of the best web development frameworks nowadays, ASP.NET MVC. I had approximately 350+ attendees, the hall was full so that there was no room for staying at feet. Besides .NET developers, there were a lot of other technology oriented developers, who has also received the presentation very well and I really hope I gave them reason to think about ASP.NET as one of the best options for web development nowadays (if you ask me, it’s the best one ;-)). I have included 10 tips in using ASP.NET MVC each of them followed by a demo. Besides these 10 tips, I have briefly introduced the concept of ASP.NET MVC for those that haven’t been working with the framework and at the end some bonus tips. I must say there was lot of laugh for some funny sentences I have stated, like “If you code ASP.NET MVC, girls will love you more” – same goes for girls, only replace girls with boys :). [LINK TO SESSION WILL GO HERE, ONCE SESSIONS ARE AVAILABLE ON MK CODECAMP WEBSITE] VOLUNTEERS Without strong organization, such events wouldn’t be able to gather hundreds of attendees at one place and still stay perfectly organized to the smallest details, without dedicated organization and volunteers. I would like to dedicate this space in my blog to them and to say one big THANK YOU for supporting us before the event and during the whole day in the event. With such young and dedicated volunteers, we couldn’t achieve anything but great results. THANK YOU EVERYONE FOR YOUR CONTRIBUTION! NETWORKING One of the main reasons why we do such events is to gather all professionals in one place. Networking is what everyone wants because through this way of networking, we can meet incredible people in one place. It is amazing feeling to share your knowledge with others and exchange thoughts on various topics. Meet and talk to interesting people. I have had very special moments with many attendees especially after my presentation. Special Thank You to all of them who come to meet me in person, whether to ask a question, say congrats for my session or simply meet me and just smile :)… everything counts! Thank You! TWITTER During the event, twitter was one of the most useful event-wide communication tool where everyone could tweet with hash tag #mkcodecamp or #mkdotnet and say what he/she wants to say about the current state and happenings at that moment… In my next blog post I will list the top craziest tweets that were posted at this event… FUTURE OF MKDOT.NET Having such strong community around MKDOT.NET, the future seems very bright. The initial plans are to have sub-groups in several technologies, however all these sub-groups will belong to the MKDOT.NET UG which will be, somehow, the HEAD of these sub-groups. We are doing this to provide better divisions by technologies and organize ourselves better since our community is very big, around 500 members in MKDOT.NET.We will have five sub-groups:- Web User Group (Lead:Hajan Selmani - me)- Mobile User Group (Lead: Filip Kerazovski)- Visual C# User Group (Lead: Vekoslav Stefanovski)- SharePoint User Group (Lead: Darko Milevski)- Dynamics User Group (Lead: Vladimir Senih) SUMMARY Online registered attendees: ~1.200 Event attendees: ~800 Number of members in organization: 40+ Organized by: MKDOT.NET User Group Number of tracks: 5 Number of speakers: 24 Number of sessions: 25 Event official website: http://codecamp.mkdot.net Total number of sponsors: 20 Platinum Sponsors: Microsoft, INETA, Telerik Place held: FON University City and Country: Skopje, Macedonia THANK YOU FOR BEING PART OF THE BEST EVENT IN MACEDONIA, CODE CAMP 2011. Regards, Hajan

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  • How To - Guide to Importing Data from a MySQL Database to Excel using MySQL for Excel

    - by Javier Treviño
    Fetching data from a database to then get it into an Excel spreadsheet to do analysis, reporting, transforming, sharing, etc. is a very common task among users. There are several ways to extract data from a MySQL database to then import it to Excel; for example you can use the MySQL Connector/ODBC to configure an ODBC connection to a MySQL database, then in Excel use the Data Connection Wizard to select the database and table from which you want to extract data from, then specify what worksheet you want to put the data into.  Another way is to somehow dump a comma delimited text file with the data from a MySQL table (using the MySQL Command Line Client, MySQL Workbench, etc.) to then in Excel open the file using the Text Import Wizard to attempt to correctly split the data in columns. These methods are fine, but involve some degree of technical knowledge to make the magic happen and involve repeating several steps each time data needs to be imported from a MySQL table to an Excel spreadsheet. So, can this be done in an easier and faster way? With MySQL for Excel you can. MySQL for Excel features an Import MySQL Data action where you can import data from a MySQL Table, View or Stored Procedure literally with a few clicks within Excel.  Following is a quick guide describing how to import data using MySQL for Excel. This guide assumes you already have a working MySQL Server instance, Microsoft Office Excel 2007 or 2010 and MySQL for Excel installed. 1. Opening MySQL for Excel Being an Excel Add-In, MySQL for Excel is opened from within Excel, so to use it open Excel, go to the Data tab located in the Ribbon and click MySQL for Excel at the far right of the Ribbon. 2. Creating a MySQL Connection (may be optional) If you have MySQL Workbench installed you will automatically see the same connections that you can see in MySQL Workbench, so you can use any of those and there may be no need to create a new connection. If you want to create a new connection (which normally you will do only once), in the Welcome Panel click New Connection, which opens the Setup New Connection dialog. Here you only need to give your new connection a distinctive Connection Name, specify the Hostname (or IP address) where the MySQL Server instance is running on (if different than localhost), the Port to connect to and the Username for the login. If you wish to test if your setup is good to go, click Test Connection and an information dialog will pop-up stating if the connection is successful or errors were found. 3.Opening a connection to a MySQL Server To open a pre-configured connection to a MySQL Server you just need to double-click it, so the Connection Password dialog is displayed where you enter the password for the login. 4. Selecting a MySQL Schema After opening a connection to a MySQL Server, the Schema Selection Panel is shown, where you can select the Schema that contains the Tables, Views and Stored Procedures you want to work with. To do so, you just need to either double-click the desired Schema or select it and click Next >. 5. Importing data… All previous steps were really the basic minimum needed to drill-down to the DB Object Selection Panel  where you can see the Database Objects (grouped by type: Tables, Views and Procedures in that order) that you want to perform actions against; in the case of this guide, the action of importing data from them. a. From a MySQL Table To import from a Table you just need to select it from the list of Database Objects’ Tables group, after selecting it you will note actions below the list become available; then click Import MySQL Data. The Import Data dialog is displayed; you can see some basic information here like the name of the Excel worksheet the data will be imported to (in the window title), the Table Name, the total Row Count and a 10 row preview of the data meant for the user to see the columns that the table contains and to provide a way to select which columns to import. The Import Data dialog is designed with defaults in place so all data is imported (all rows and all columns) by just clicking Import; this is important to minimize the number of clicks needed to get the job done. After the import is performed you will have the data in the Excel worksheet formatted automatically. If you need to override the defaults in the Import Data dialog to change the columns selected for import or to change the number of imported rows you can easily do so before clicking Import. In the screenshot below the defaults are overridden to import only the first 3 columns and rows 10 – 60 (Limit to 50 Rows and Start with Row 10). If the number of rows to be imported exceeds the maximum number of rows Excel can hold in its worksheet, a warning will be displayed in the dialog, meaning the imported number of rows will be limited by that maximum number (65,535 rows if the worksheet is in Compatibility Mode).  In the screenshot below you can see the Table contains 80,559 rows, but only 65,534 rows will be imported since the first row is used for the column names if the Include Column Names as Headers checkbox is checked. b. From a MySQL View Similar to the way of importing from a Table, to import from a View you just need to select it from the list of Database Objects’ Views group, then click Import MySQL Data. The Import Data dialog is displayed; identically to the way everything looks when importing from a table, the dialog displays the View Name, the total Row Count and the data preview grid. Since Views are really a filtered way to display data from Tables, it is actually as if we are extracting data from a Table; so the Import Data dialog is actually identical for those 2 Database Objects. After the import is performed, the data in the Excel spreadsheet looks like the following screenshot. Note that you can override the defaults in the Import Data dialog in the same way described above for importing data from Tables. Also the Compatibility Mode warning will be displayed if data exceeds the maximum number of rows explained before. c. From a MySQL Procedure Too import from a Procedure you just need to select it from the list of Database Objects’ Procedures group (note you can see Procedures here but not Functions since these return a single value, so by design they are filtered out). After the selection is made, click Import MySQL Data. The Import Data dialog is displayed, but this time you can see it looks different to the one used for Tables and Views.  Given the nature of Store Procedures, they require first that values are supplied for its Parameters and also Procedures can return multiple Result Sets; so the Import Data dialog shows the Procedure Name and the Procedure Parameters in a grid where their values are input. After you supply the Parameter Values click Call. After calling the Procedure, the Result Sets returned by it are displayed at the bottom of the dialog; output parameters and the return value of the Procedure are appended as the last Result Set of the group. You can see each Result Set is displayed as a tab so you can see a preview of the returned data.  You can specify if you want to import the Selected Result Set (default), All Result Sets – Arranged Horizontally or All Result Sets – Arranged Vertically using the Import drop-down list; then click Import. After the import is performed, the data in the Excel spreadsheet looks like the following screenshot.  Note in this example all Result Sets were imported and arranged vertically. As you can see using MySQL for Excel importing data from a MySQL database becomes an easy task that requires very little technical knowledge, so it can be done by any type of user. Hope you enjoyed this guide! Remember that your feedback is very important for us, so drop us a message: MySQL on Windows (this) Blog - https://blogs.oracle.com/MySqlOnWindows/ Forum - http://forums.mysql.com/list.php?172 Facebook - http://www.facebook.com/mysql Cheers!

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  • MySQL Cluster 7.2: Over 8x Higher Performance than Cluster 7.1

    - by Mat Keep
    0 0 1 893 5092 Homework 42 11 5974 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} Summary The scalability enhancements delivered by extensions to multi-threaded data nodes enables MySQL Cluster 7.2 to deliver over 8x higher performance than the previous MySQL Cluster 7.1 release on a recent benchmark What’s New in MySQL Cluster 7.2 MySQL Cluster 7.2 was released as GA (Generally Available) in February 2012, delivering many enhancements to performance on complex queries, new NoSQL Key / Value API, cross-data center replication and ease-of-use. These enhancements are summarized in the Figure below, and detailed in the MySQL Cluster New Features whitepaper Figure 1: Next Generation Web Services, Cross Data Center Replication and Ease-of-Use Once of the key enhancements delivered in MySQL Cluster 7.2 is extensions made to the multi-threading processes of the data nodes. Multi-Threaded Data Node Extensions The MySQL Cluster 7.2 data node is now functionally divided into seven thread types: 1) Local Data Manager threads (ldm). Note – these are sometimes also called LQH threads. 2) Transaction Coordinator threads (tc) 3) Asynchronous Replication threads (rep) 4) Schema Management threads (main) 5) Network receiver threads (recv) 6) Network send threads (send) 7) IO threads Each of these thread types are discussed in more detail below. MySQL Cluster 7.2 increases the maximum number of LDM threads from 4 to 16. The LDM contains the actual data, which means that when using 16 threads the data is more heavily partitioned (this is automatic in MySQL Cluster). Each LDM thread maintains its own set of data partitions, index partitions and REDO log. The number of LDM partitions per data node is not dynamically configurable, but it is possible, however, to map more than one partition onto each LDM thread, providing flexibility in modifying the number of LDM threads. The TC domain stores the state of in-flight transactions. This means that every new transaction can easily be assigned to a new TC thread. Testing has shown that in most cases 1 TC thread per 2 LDM threads is sufficient, and in many cases even 1 TC thread per 4 LDM threads is also acceptable. Testing also demonstrated that in some instances where the workload needed to sustain very high update loads it is necessary to configure 3 to 4 TC threads per 4 LDM threads. In the previous MySQL Cluster 7.1 release, only one TC thread was available. This limit has been increased to 16 TC threads in MySQL Cluster 7.2. The TC domain also manages the Adaptive Query Localization functionality introduced in MySQL Cluster 7.2 that significantly enhanced complex query performance by pushing JOIN operations down to the data nodes. Asynchronous Replication was separated into its own thread with the release of MySQL Cluster 7.1, and has not been modified in the latest 7.2 release. To scale the number of TC threads, it was necessary to separate the Schema Management domain from the TC domain. The schema management thread has little load, so is implemented with a single thread. The Network receiver domain was bound to 1 thread in MySQL Cluster 7.1. With the increase of threads in MySQL Cluster 7.2 it is also necessary to increase the number of recv threads to 8. This enables each receive thread to service one or more sockets used to communicate with other nodes the Cluster. The Network send thread is a new thread type introduced in MySQL Cluster 7.2. Previously other threads handled the sending operations themselves, which can provide for lower latency. To achieve highest throughput however, it has been necessary to create dedicated send threads, of which 8 can be configured. It is still possible to configure MySQL Cluster 7.2 to a legacy mode that does not use any of the send threads – useful for those workloads that are most sensitive to latency. The IO Thread is the final thread type and there have been no changes to this domain in MySQL Cluster 7.2. Multiple IO threads were already available, which could be configured to either one thread per open file, or to a fixed number of IO threads that handle the IO traffic. Except when using compression on disk, the IO threads typically have a very light load. Benchmarking the Scalability Enhancements The scalability enhancements discussed above have made it possible to scale CPU usage of each data node to more than 5x of that possible in MySQL Cluster 7.1. In addition, a number of bottlenecks have been removed, making it possible to scale data node performance by even more than 5x. Figure 2: MySQL Cluster 7.2 Delivers 8.4x Higher Performance than 7.1 The flexAsynch benchmark was used to compare MySQL Cluster 7.2 performance to 7.1 across an 8-node Intel Xeon x5670-based cluster of dual socket commodity servers (6 cores each). As the results demonstrate, MySQL Cluster 7.2 delivers over 8x higher performance per data nodes than MySQL Cluster 7.1. More details of this and other benchmarks will be published in a new whitepaper – coming soon, so stay tuned! In a following blog post, I’ll provide recommendations on optimum thread configurations for different types of server processor. You can also learn more from the Best Practices Guide to Optimizing Performance of MySQL Cluster Conclusion MySQL Cluster has achieved a range of impressive benchmark results, and set in context with the previous 7.1 release, is able to deliver over 8x higher performance per node. As a result, the multi-threaded data node extensions not only serve to increase performance of MySQL Cluster, they also enable users to achieve significantly improved levels of utilization from current and future generations of massively multi-core, multi-thread processor designs.

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  • Anatomy of a .NET Assembly - Custom attribute encoding

    - by Simon Cooper
    In my previous post, I covered how field, method, and other types of signatures are encoded in a .NET assembly. Custom attribute signatures differ quite a bit from these, which consequently affects attribute specifications in C#. Custom attribute specifications In C#, you can apply a custom attribute to a type or type member, specifying a constructor as well as the values of fields or properties on the attribute type: public class ExampleAttribute : Attribute { public ExampleAttribute(int ctorArg1, string ctorArg2) { ... } public Type ExampleType { get; set; } } [Example(5, "6", ExampleType = typeof(string))] public class C { ... } How does this specification actually get encoded and stored in an assembly? Specification blob values Custom attribute specification signatures use the same building blocks as other types of signatures; the ELEMENT_TYPE structure. However, they significantly differ from other types of signatures, in that the actual parameter values need to be stored along with type information. There are two types of specification arguments in a signature blob; fixed args and named args. Fixed args are the arguments to the attribute type constructor, named arguments are specified after the constructor arguments to provide a value to a field or property on the constructed attribute type (PropertyName = propValue) Values in an attribute blob are limited to one of the basic types (one of the number types, character, or boolean), a reference to a type, an enum (which, in .NET, has to use one of the integer types as a base representation), or arrays of any of those. Enums and the basic types are easy to store in a blob - you simply store the binary representation. Strings are stored starting with a compressed integer indicating the length of the string, followed by the UTF8 characters. Array values start with an integer indicating the number of elements in the array, then the item values concatentated together. Rather than using a coded token, Type values are stored using a string representing the type name and fully qualified assembly name (for example, MyNs.MyType, MyAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0123456789abcdef). If the type is in the current assembly or mscorlib then just the type name can be used. This is probably done to prevent direct references between assemblies solely because of attribute specification arguments; assemblies can be loaded in the reflection-only context and attribute arguments still processed, without loading the entire assembly. Fixed and named arguments Each entry in the CustomAttribute metadata table contains a reference to the object the attribute is applied to, the attribute constructor, and the specification blob. The number and type of arguments to the constructor (the fixed args) can be worked out by the method signature referenced by the attribute constructor, and so the fixed args can simply be concatenated together in the blob without any extra type information. Named args are different. These specify the value to assign to a field or property once the attribute type has been constructed. In the CLR, fields and properties can be overloaded just on their type; different fields and properties can have the same name. Therefore, to uniquely identify a field or property you need: Whether it's a field or property (indicated using byte values 0x53 and 0x54, respectively) The field or property type The field or property name After the fixed arg values is a 2-byte number specifying the number of named args in the blob. Each named argument has the above information concatenated together, mostly using the basic ELEMENT_TYPE values, in the same way as a method or field signature. A Type argument is represented using the byte 0x50, and an enum argument is represented using the byte 0x55 followed by a string specifying the name and assembly of the enum type. The named argument property information is followed by the argument value, using the same encoding as fixed args. Boxed objects This would be all very well, were it not for object and object[]. Arguments and properties of type object allow a value of any allowed argument type to be specified. As a result, more information needs to be specified in the blob to interpret the argument bytes as the correct type. So, the argument value is simple prepended with the type of the value by specifying the ELEMENT_TYPE or name of the enum the value represents. For named arguments, a field or property of type object is represented using the byte 0x51, with the actual type specified in the argument value. Some examples... All property signatures start with the 2-byte value 0x0001. Similar to my previous post in the series, names in capitals correspond to a particular byte value in the ELEMENT_TYPE structure. For strings, I'll simply give the string value, rather than the length and UTF8 encoding in the actual blob. I'll be using the following enum and attribute types to demonstrate specification encodings: class AttrAttribute : Attribute { public AttrAttribute() {} public AttrAttribute(Type[] tArray) {} public AttrAttribute(object o) {} public AttrAttribute(MyEnum e) {} public AttrAttribute(ushort x, int y) {} public AttrAttribute(string str, Type type1, Type type2) {} public int Prop1 { get; set; } public object Prop2 { get; set; } public object[] ObjectArray; } enum MyEnum : int { Val1 = 1, Val2 = 2 } Now, some examples: Here, the the specification binds to the (ushort, int) attribute constructor, with fixed args only. The specification blob starts off with a prolog, followed by the two constructor arguments, then the number of named arguments (zero): [Attr(42, 84)] 0x0001 0x002a 0x00000054 0x0000 An example of string and type encoding: [Attr("MyString", typeof(Array), typeof(System.Windows.Forms.Form))] 0x0001 "MyString" "System.Array" "System.Windows.Forms.Form, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" 0x0000 As you can see, the full assembly specification of a type is only needed if the type isn't in the current assembly or mscorlib. Note, however, that the C# compiler currently chooses to fully-qualify mscorlib types anyway. An object argument (this binds to the object attribute constructor), and two named arguments (a null string is represented by 0xff and the empty string by 0x00) [Attr((ushort)40, Prop1 = 12, Prop2 = "")] 0x0001 U2 0x0028 0x0002 0x54 I4 "Prop1" 0x0000000c 0x54 0x51 "Prop2" STRING 0x00 Right, more complicated now. A type array as a fixed argument: [Attr(new[] { typeof(string), typeof(object) })] 0x0001 0x00000002 // the number of elements "System.String" "System.Object" 0x0000 An enum value, which is simply represented using the underlying value. The CLR works out that it's an enum using information in the attribute constructor signature: [Attr(MyEnum.Val1)] 0x0001 0x00000001 0x0000 And finally, a null array, and an object array as a named argument: [Attr((Type[])null, ObjectArray = new object[] { (byte)2, typeof(decimal), null, MyEnum.Val2 })] 0x0001 0xffffffff 0x0001 0x53 SZARRAY 0x51 "ObjectArray" 0x00000004 U1 0x02 0x50 "System.Decimal" STRING 0xff 0x55 "MyEnum" 0x00000002 As you'll notice, a null object is encoded as a null string value, and a null array is represented using a length of -1 (0xffffffff). How does this affect C#? So, we can now explain why the limits on attribute arguments are so strict in C#. Attribute specification blobs are limited to basic numbers, enums, types, and arrays. As you can see, this is because the raw CLR encoding can only accommodate those types. Special byte patterns have to be used to indicate object, string, Type, or enum values in named arguments; you can't specify an arbitary object type, as there isn't a generalised way of encoding the resulting value in the specification blob. In particular, decimal values can't be encoded, as it isn't a 'built-in' CLR type that has a native representation (you'll notice that decimal constants in C# programs are compiled as several integer arguments to DecimalConstantAttribute). Jagged arrays also aren't natively supported, although you can get around it by using an array as a value to an object argument: [Attr(new object[] { new object[] { new Type[] { typeof(string) } }, 42 })] Finally... Phew! That was a bit longer than I thought it would be. Custom attribute encodings are complicated! Hopefully this series has been an informative look at what exactly goes on inside a .NET assembly. In the next blog posts, I'll be carrying on with the 'Inside Red Gate' series.

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  • Organization &amp; Architecture UNISA Studies &ndash; Chap 4

    - by MarkPearl
    Learning Outcomes Explain the characteristics of memory systems Describe the memory hierarchy Discuss cache memory principles Discuss issues relevant to cache design Describe the cache organization of the Pentium Computer Memory Systems There are key characteristics of memory… Location – internal or external Capacity – expressed in terms of bytes Unit of Transfer – the number of bits read out of or written into memory at a time Access Method – sequential, direct, random or associative From a users perspective the two most important characteristics of memory are… Capacity Performance – access time, memory cycle time, transfer rate The trade off for memory happens along three axis… Faster access time, greater cost per bit Greater capacity, smaller cost per bit Greater capacity, slower access time This leads to people using a tiered approach in their use of memory   As one goes down the hierarchy, the following occurs… Decreasing cost per bit Increasing capacity Increasing access time Decreasing frequency of access of the memory by the processor The use of two levels of memory to reduce average access time works in principle, but only if conditions 1 to 4 apply. A variety of technologies exist that allow us to accomplish this. Thus it is possible to organize data across the hierarchy such that the percentage of accesses to each successively lower level is substantially less than that of the level above. A portion of main memory can be used as a buffer to hold data temporarily that is to be read out to disk. This is sometimes referred to as a disk cache and improves performance in two ways… Disk writes are clustered. Instead of many small transfers of data, we have a few large transfers of data. This improves disk performance and minimizes processor involvement. Some data designed for write-out may be referenced by a program before the next dump to disk. In that case the data is retrieved rapidly from the software cache rather than slowly from disk. Cache Memory Principles Cache memory is substantially faster than main memory. A caching system works as follows.. When a processor attempts to read a word of memory, a check is made to see if this in in cache memory… If it is, the data is supplied, If it is not in the cache, a block of main memory, consisting of a fixed number of words is loaded to the cache. Because of the phenomenon of locality of references, when a block of data is fetched into the cache, it is likely that there will be future references to that same memory location or to other words in the block. Elements of Cache Design While there are a large number of cache implementations, there are a few basic design elements that serve to classify and differentiate cache architectures… Cache Addresses Cache Size Mapping Function Replacement Algorithm Write Policy Line Size Number of Caches Cache Addresses Almost all non-embedded processors support virtual memory. Virtual memory in essence allows a program to address memory from a logical point of view without needing to worry about the amount of physical memory available. When virtual addresses are used the designer may choose to place the cache between the MMU (memory management unit) and the processor or between the MMU and main memory. The disadvantage of virtual memory is that most virtual memory systems supply each application with the same virtual memory address space (each application sees virtual memory starting at memory address 0), which means the cache memory must be completely flushed with each application context switch or extra bits must be added to each line of the cache to identify which virtual address space the address refers to. Cache Size We would like the size of the cache to be small enough so that the overall average cost per bit is close to that of main memory alone and large enough so that the overall average access time is close to that of the cache alone. Also, larger caches are slightly slower than smaller ones. Mapping Function Because there are fewer cache lines than main memory blocks, an algorithm is needed for mapping main memory blocks into cache lines. The choice of mapping function dictates how the cache is organized. Three techniques can be used… Direct – simplest technique, maps each block of main memory into only one possible cache line Associative – Each main memory block to be loaded into any line of the cache Set Associative – exhibits the strengths of both the direct and associative approaches while reducing their disadvantages For detailed explanations of each approach – read the text book (page 148 – 154) Replacement Algorithm For associative and set associating mapping a replacement algorithm is needed to determine which of the existing blocks in the cache must be replaced by a new block. There are four common approaches… LRU (Least recently used) FIFO (First in first out) LFU (Least frequently used) Random selection Write Policy When a block resident in the cache is to be replaced, there are two cases to consider If no writes to that block have happened in the cache – discard it If a write has occurred, a process needs to be initiated where the changes in the cache are propagated back to the main memory. There are several approaches to achieve this including… Write Through – all writes to the cache are done to the main memory as well at the point of the change Write Back – when a block is replaced, all dirty bits are written back to main memory The problem is complicated when we have multiple caches, there are techniques to accommodate for this but I have not summarized them. Line Size When a block of data is retrieved and placed in the cache, not only the desired word but also some number of adjacent words are retrieved. As the block size increases from very small to larger sizes, the hit ratio will at first increase because of the principle of locality, which states that the data in the vicinity of a referenced word are likely to be referenced in the near future. As the block size increases, more useful data are brought into cache. The hit ratio will begin to decrease as the block becomes even bigger and the probability of using the newly fetched information becomes less than the probability of using the newly fetched information that has to be replaced. Two specific effects come into play… Larger blocks reduce the number of blocks that fit into a cache. Because each block fetch overwrites older cache contents, a small number of blocks results in data being overwritten shortly after they are fetched. As a block becomes larger, each additional word is farther from the requested word and therefore less likely to be needed in the near future. The relationship between block size and hit ratio is complex, and no set approach is judged to be the best in all circumstances.   Pentium 4 and ARM cache organizations The processor core consists of four major components: Fetch/decode unit – fetches program instruction in order from the L2 cache, decodes these into a series of micro-operations, and stores the results in the L2 instruction cache Out-of-order execution logic – Schedules execution of the micro-operations subject to data dependencies and resource availability – thus micro-operations may be scheduled for execution in a different order than they were fetched from the instruction stream. As time permits, this unit schedules speculative execution of micro-operations that may be required in the future Execution units – These units execute micro-operations, fetching the required data from the L1 data cache and temporarily storing results in registers Memory subsystem – This unit includes the L2 and L3 caches and the system bus, which is used to access main memory when the L1 and L2 caches have a cache miss and to access the system I/O resources

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