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  • what is the probability that the next random number will equal current one?

    - by I__
    if i do this in a worksheet: =RAND() i also specified that i want only 2 decimal places and for example let's say that rand() = 0.07 what is the probability that when i call this function again i will get 0.07 ?? i know that ideally if we assume 100% randomness, the answer would be 1/ (10 * 10) because there are only 100 possible combinations, but what would it be according to the way excel generates a random number?

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  • How to check of which user-defined type a current JSON element is during $.each()?

    - by Bob
    I have the following structure for a JSON file: ({condos:[{Address:'123 Fake St.', Lat:'56.645654', Lng:'23.534546'},{... another condo ...},{...}],houses:[{Address:'1 Main Ave.', Lat:'34.765766', Lng:'27.8786674'},{... another house ...}, {...}]}) So, I have a list of condos and houses in one big JSON array. I want to plot them all on my map, but I want to give condos and houses different marker icons( blue marker for condos, green marker for houses ). Problem I have is - figuring out how to distinguish between types of markers when I $.each() through them. How would I use if to check whether I'm working with a condo or a house at the moment? var markers = null; $('#map').gmap(mapOptions).bind('init', function(){ $.post('getMarkers.php', function(json){ markers = json; $.each(markers, function(type, dataMembers) { $.each(dataMembers, function(i, j){ //if house use house.png to create marker $('#map').gmap('addMarker', { 'position': new google.maps.LatLng(parseFloat(Lat), parseFloat(Lng)), 'bounds':true, 'icon':'house.png' } ); //if condo use condo.png $('#map').gmap('addMarker', { 'position': new google.maps.LatLng(parseFloat(Lat), parseFloat(Lng)), 'bounds':true, 'icon':'condo.png' } ); }); }); }); });

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  • How to current snapshot of MySQL Table and store it into CSV file(after creating it) ?

    - by Rachel
    I have large database table, approximately 5GB, now I wan to getCurrentSnapshot of Database using "Select * from MyTableName", am using PDO in PHP to interact with Database. So preparing a query and then executing it // Execute the prepared query $result->execute(); $resultCollection = $result->fetchAll(PDO::FETCH_ASSOC); is not an efficient way as lots of memory is being user for storing into the associative array data which is approximately, 5GB. My final goal is to collect data returned by Select query into an CSV file and put CSV file at an FTP Location from where Client can get it. Other Option I thought was to do: SELECT * INTO OUTFILE "c:/mydata.csv" FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY "\n" FROM my_table; But I am not sure if this would work as I have cron that initiates the complete process and we do not have an csv file, so basically for this approach, PHP Scripts will have to create an CSV file. Do a Select query on the database. Store the select query result into the CSV file. What would be the best or efficient way to do this kind of task ? Any Suggestions !!!

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  • how i insert values from list of Data Grid View,current time ,EmployeeID using button click event (C

    - by Six fourty
    hi, it show me this error Incorrect syntax near the keyword 'Select' to make to clear Employee ID in this case is FK in the table (Attendance detail) and the other thing is i am using Data Grid View from another table(Employee information) to Show the list of the staff in my form. then i want to transfer each selected cell value from Data Grid View to attendance detail table. 10q private void time_in_Click(object sender, EventArgs e) { employee_InformationDataGridView.SelectedCells[0].Style.ForeColor = Color.Green; time_in.Enabled = false; time_out.Enabled = true; con = new SqlConnection(GlobalClass.conn); con.Open(); SqlCommand cmd = new SqlCommand("Insert into Attendancedetail Values(" + "Select from EmployeeInformation(EmployeeID)" + ",'" + employee_InformationDataGridView.SelectedCells[0] + "','" + DateTime.Now.ToLongDateString() + "','" + null + "','" + null + "','" + DateTime.Now.ToLongTimeString() + "'," + null + ")", con); int i = cmd.ExecuteNonQuery(); MessageBox.Show(i.ToString() + " record inserted"); }

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  • Is it possible to get the current request that is being served by node.js?

    - by user420504
    I am using express.js. I have a need to be able to log certain request data whenever someone tries to log a message. For this I would like to create a helper method like so function log_message(level, message){ winston.log(level, req.path + "" + message); } I would then use the method like so. exports.index = function(req, res){ log_message("info", "I'm here"); } Note that I am not passing the req object to the log_message function. I want that to be transparently done so that the log_message API user does not need to be aware of the common data that is being logged. Is there a way to achieve this with express.js/node.js. Is the request object available from a global variable of some sort?

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  • Accessing current class through $this-> from a function called statically. [PHP]

    - by MQA
    This feels a bit messy, but I'd like to be able to call a member function statically, yet have the rest of the class behave normally... Example: <?php class Email { private $username = 'user'; private $password = 'password'; private $from = '[email protected]'; public $to; public function SendMsg($to, $body) { if (isset($this)) $email &= $this; else $email = new Email(); $email->to = $to; // Rest of function... } } Email::SendMsg('[email protected]'); How best do I allow the static function call in this example? Thanks!

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  • Closest location - Heapify or Build-heap

    - by Trevor Adams
    So lets say we have a set of gps data points and your current location. If asked to give the closest point to your current location we can utilize a heap with the distance being the key. Now if we update the current location, I suspect that only a few of the keys will change enough to violate the heap property. Would it be more efficient to rebuild the heap after recalculating the keys or to run heapify (assuming that only a few of the keys have changed enough). It is assumed that we don't jump around with the new location (new current location is close to the last current location).

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  • Migrating Ruby on Rails Website to New Server (Linux)

    - by GarytheWorm
    I have an existing website that is a Ruby on Rails project. I have another server i need to transfer the existing website too. The server i wish to transfer too was originally hosting the website so has the necessary gems/configuration are installed. I have tar the current releases shared dir from the old server and transfered them over to the new server. I have then unpack the tar in the apps directory to the new location which is a different URL path. My problem is now as you can see below that the path on the current - is pointing to the old url. ( i ran ls -la to see owenership) How can i change this current path to read with my new web address? current releases shared sitepack.tar root@server1:/var/www/clients/client1/NEWSITE.com/web/apps# ls -la current - /var/www/OLDSITE.com/web/apps/releases/20120130171636 root@server1:/var/www/clients/client1/NEWSITE.com/web/apps#

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  • Producer and Consumer Threads Hang

    - by user972425
    So this is my first foray into threads and thus far it is driving me insane. My problem seems to be some kind of synchronization error that causes my consumer thread to hang. I've looked at other code and just about everything I could find and I can't find what my error is. There also seems to be a discrepancy between the code being executed in Eclipse and via javac in the command line. Intention - Using a bounded buffer (with 1000 slots) create and consume 1,000,000 doubles. Use only notify and wait. Problem - In Eclipse the consumer thread will occasionally hang around 940,000 iterations, but other times completes. In the command line the consumer thread always hangs. Output - Eclipse - Successful Producer has produced 100000 doubles. Consumer has consumed 100000 doubles. Producer has produced 200000 doubles. Consumer has consumed 200000 doubles. Producer has produced 300000 doubles. Consumer has consumed 300000 doubles. Producer has produced 400000 doubles. Consumer has consumed 400000 doubles. Producer has produced 500000 doubles. Consumer has consumed 500000 doubles. Producer has produced 600000 doubles. Consumer has consumed 600000 doubles. Producer has produced 700000 doubles. Consumer has consumed 700000 doubles. Producer has produced 800000 doubles. Consumer has consumed 800000 doubles. Producer has produced 900000 doubles. Consumer has consumed 900000 doubles. Producer has produced 1000000 doubles. Producer has produced all items. Consumer has consumed 1000000 doubles. Consumer has consumed all items. Exitting Output - Command Line/Eclipse - Unsuccessful Producer has produced 100000 doubles. Consumer has consumed 100000 doubles. Producer has produced 200000 doubles. Consumer has consumed 200000 doubles. Producer has produced 300000 doubles. Consumer has consumed 300000 doubles. Producer has produced 400000 doubles. Consumer has consumed 400000 doubles. Producer has produced 500000 doubles. Consumer has consumed 500000 doubles. Producer has produced 600000 doubles. Consumer has consumed 600000 doubles. Producer has produced 700000 doubles. Consumer has consumed 700000 doubles. Producer has produced 800000 doubles. Consumer has consumed 800000 doubles. Producer has produced 900000 doubles. Consumer has consumed 900000 doubles. Producer has produced 1000000 doubles. Producer has produced all items. At this point it just sits and hangs. Any help you can provide about where I might have misstepped is greatly appreciated. Code - Producer thread import java.text.DecimalFormat;+ " doubles. Cumulative value of generated items= " + temp) import java.util.*; import java.io.*; public class producer implements Runnable{ private buffer produceBuff; public producer (buffer buff){ produceBuff = buff; } public void run(){ Random random = new Random(); double temp = 0, randomElem; DecimalFormat df = new DecimalFormat("#.###"); for(int i = 1; i<=1000000; i++) { randomElem = (Double.parseDouble( df.format(random.nextDouble() * 100.0))); try { produceBuff.add(randomElem); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } temp+= randomElem; if(i%100000 == 0) {produceBuff.print("Producer has produced "+ i ); } } produceBuff.print("Producer has produced all items."); } } Consumer thread import java.util.*; import java.io.*; public class consumer implements Runnable{ private buffer consumBuff; public consumer (buffer buff){ consumBuff = buff; } public void run(){ double temp = 0; for(int i = 1; i<=1000000; i++) { try { temp += consumBuff.get(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(i%100000 == 0) {consumBuff.print("Consumer has consumed "+ i ); //if(i>999000) //{System.out.println("Consuming item " + i);} } consumBuff.print("Consumer has consumed all items."); } } Buffer/Main import java.util.*; import java.io.*; public class buffer { private double buff[]; private int addPlace; private int getPlace; public buffer(){ buff = new double[1000]; addPlace = 0; getPlace = 0; } public synchronized void add(double add) throws InterruptedException{ if((addPlace+1 == getPlace) ) { try { wait(); } catch (InterruptedException e) {throw e;} } buff[addPlace] = add; addPlace = (addPlace+1)%1000; notify(); } public synchronized double get()throws InterruptedException{ if(getPlace == addPlace) { try { wait(); } catch (InterruptedException e) {throw e;} } double temp = buff[getPlace]; getPlace = (getPlace+1)%1000; notify(); return temp; } public synchronized void print(String view) { System.out.println(view); } public static void main(String args[]){ buffer buf = new buffer(); Thread produce = new Thread(new producer(buf)); Thread consume = new Thread(new consumer(buf)); produce.start(); consume.start(); try { produce.join(); consume.join(); } catch (InterruptedException e) {return;} System.out.println("Exitting"); } }

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  • How to autostart this slide

    - by lchales
    Hello there: first of all i have no idea on coding or anything related, simple question: is there any simple way to tell this code to autostart the slide? at the current moment the images change on click. currently the index page only have one image, what i want is to add a few but without the need to click to see the next one here is the code from my index: <script type="text/javascript"> //<![CDATA[ /* the images preload plugin */ (function($) { $.fn.preload = function(options) { var opts = $.extend({}, $.fn.preload.defaults, options), o = $.meta ? $.extend({}, opts, this.data()) : opts; var c = this.length, l = 0; return this.each(function() { var $i = $(this); $('<img/>').load(function(i){ ++l; if(l == c) o.onComplete(); }).attr('src',$i.attr('src')); }); }; $.fn.preload.defaults = { onComplete : function(){return false;} }; })(jQuery); //]]> </script><script type="text/javascript"> //<![CDATA[ $(function() { var $tf_bg = $('#tf_bg'), $tf_bg_images = $tf_bg.find('img'), $tf_bg_img = $tf_bg_images.eq(0), $tf_thumbs = $('#tf_thumbs'), total = $tf_bg_images.length, current = 0, $tf_content_wrapper = $('#tf_content_wrapper'), $tf_next = $('#tf_next'), $tf_prev = $('#tf_prev'), $tf_loading = $('#tf_loading'); //preload the images $tf_bg_images.preload({ onComplete : function(){ $tf_loading.hide(); init(); } }); //shows the first image and initializes events function init(){ //get dimentions for the image, based on the windows size var dim = getImageDim($tf_bg_img); //set the returned values and show the image $tf_bg_img.css({ width : dim.width, height : dim.height, left : dim.left, top : dim.top }).fadeIn(); //resizing the window resizes the $tf_bg_img $(window).bind('resize',function(){ var dim = getImageDim($tf_bg_img); $tf_bg_img.css({ width : dim.width, height : dim.height, left : dim.left, top : dim.top }); }); //expand and fit the image to the screen $('#tf_zoom').live('click', function(){ if($tf_bg_img.is(':animated')) return false; var $this = $(this); if($this.hasClass('tf_zoom')){ resize($tf_bg_img); $this.addClass('tf_fullscreen') .removeClass('tf_zoom'); } else{ var dim = getImageDim($tf_bg_img); $tf_bg_img.animate({ width : dim.width, height : dim.height, top : dim.top, left : dim.left },350); $this.addClass('tf_zoom') .removeClass('tf_fullscreen'); } } ); //click the arrow down, scrolls down $tf_next.bind('click',function(){ if($tf_bg_img.is(':animated')) return false; scroll('tb'); }); //click the arrow up, scrolls up $tf_prev.bind('click',function(){ if($tf_bg_img.is(':animated')) return false; scroll('bt'); }); //mousewheel events - down / up button trigger the scroll down / up $(document).mousewheel(function(e, delta) { if($tf_bg_img.is(':animated')) return false; if(delta > 0) scroll('bt'); else scroll('tb'); return false; }); //key events - down / up button trigger the scroll down / up $(document).keydown(function(e){ if($tf_bg_img.is(':animated')) return false; switch(e.which){ case 38: scroll('bt'); break; case 40: scroll('tb'); break; } }); } //show next / prev image function scroll(dir){ //if dir is "tb" (top -> bottom) increment current, //else if "bt" decrement it current = (dir == 'tb')?current + 1:current - 1; //we want a circular slideshow, //so we need to check the limits of current if(current == total) current = 0; else if(current < 0) current = total - 1; //flip the thumb $tf_thumbs.flip({ direction : dir, speed : 400, onBefore : function(){ //the new thumb is set here var content = '<span id="tf_zoom" class="tf_zoom"><\/span>'; content +='<img src="' + $tf_bg_images.eq(current).attr('longdesc') + '" alt="Thumb' + (current+1) + '"/>'; $tf_thumbs.html(content); } }); //we get the next image var $tf_bg_img_next = $tf_bg_images.eq(current), //its dimentions dim = getImageDim($tf_bg_img_next), //the top should be one that makes the image out of the viewport //the image should be positioned up or down depending on the direction top = (dir == 'tb')?$(window).height() + 'px':-parseFloat(dim.height,10) + 'px'; //set the returned values and show the next image $tf_bg_img_next.css({ width : dim.width, height : dim.height, left : dim.left, top : top }).show(); //now slide it to the viewport $tf_bg_img_next.stop().animate({ top : dim.top },700); //we want the old image to slide in the same direction, out of the viewport var slideTo = (dir == 'tb')?-$tf_bg_img.height() + 'px':$(window).height() + 'px'; $tf_bg_img.stop().animate({ top : slideTo },700,function(){ //hide it $(this).hide(); //the $tf_bg_img is now the shown image $tf_bg_img = $tf_bg_img_next; //show the description for the new image $tf_content_wrapper.children() .eq(current) .show(); }); //hide the current description $tf_content_wrapper.children(':visible') .hide() } //animate the image to fit in the viewport function resize($img){ var w_w = $(window).width(), w_h = $(window).height(), i_w = $img.width(), i_h = $img.height(), r_i = i_h / i_w, new_w,new_h; if(i_w > i_h){ new_w = w_w; new_h = w_w * r_i; if(new_h > w_h){ new_h = w_h; new_w = w_h / r_i; } } else{ new_h = w_w * r_i; new_w = w_w; } $img.animate({ width : new_w + 'px', height : new_h + 'px', top : '0px', left : '0px' },350); } //get dimentions of the image, //in order to make it full size and centered function getImageDim($img){ var w_w = $(window).width(), w_h = $(window).height(), r_w = w_h / w_w, i_w = $img.width(), i_h = $img.height(), r_i = i_h / i_w, new_w,new_h, new_left,new_top; if(r_w > r_i){ new_h = w_h; new_w = w_h / r_i; } else{ new_h = w_w * r_i; new_w = w_w; } return { width : new_w + 'px', height : new_h + 'px', left : (w_w - new_w) / 2 + 'px', top : (w_h - new_h) / 2 + 'px' }; } }); //]]> </script>

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  • Using R to Analyze G1GC Log Files

    - by user12620111
    Using R to Analyze G1GC Log Files body, td { font-family: sans-serif; background-color: white; font-size: 12px; margin: 8px; } tt, code, pre { font-family: 'DejaVu Sans Mono', 'Droid Sans Mono', 'Lucida Console', Consolas, Monaco, monospace; } h1 { font-size:2.2em; } h2 { font-size:1.8em; } h3 { font-size:1.4em; } h4 { font-size:1.0em; } h5 { font-size:0.9em; } h6 { font-size:0.8em; } a:visited { color: rgb(50%, 0%, 50%); } pre { margin-top: 0; max-width: 95%; border: 1px solid #ccc; white-space: pre-wrap; } pre code { display: block; padding: 0.5em; } code.r, code.cpp { background-color: #F8F8F8; } table, td, th { border: none; } blockquote { color:#666666; margin:0; padding-left: 1em; border-left: 0.5em #EEE solid; } hr { height: 0px; border-bottom: none; border-top-width: thin; border-top-style: dotted; border-top-color: #999999; } @media print { * { background: transparent !important; color: black !important; filter:none !important; -ms-filter: none !important; } body { font-size:12pt; max-width:100%; } a, a:visited { text-decoration: underline; } hr { visibility: hidden; page-break-before: always; } pre, blockquote { padding-right: 1em; page-break-inside: avoid; } tr, img { page-break-inside: avoid; } img { max-width: 100% !important; } @page :left { margin: 15mm 20mm 15mm 10mm; } @page :right { margin: 15mm 10mm 15mm 20mm; } p, h2, h3 { orphans: 3; widows: 3; } h2, h3 { page-break-after: avoid; } } pre .operator, pre .paren { color: rgb(104, 118, 135) } pre .literal { color: rgb(88, 72, 246) } pre .number { color: rgb(0, 0, 205); } pre .comment { color: rgb(76, 136, 107); } pre .keyword { color: rgb(0, 0, 255); } pre .identifier { color: rgb(0, 0, 0); } pre .string { color: rgb(3, 106, 7); } var hljs=new function(){function m(p){return p.replace(/&/gm,"&").replace(/"}while(y.length||w.length){var v=u().splice(0,1)[0];z+=m(x.substr(q,v.offset-q));q=v.offset;if(v.event=="start"){z+=t(v.node);s.push(v.node)}else{if(v.event=="stop"){var 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  Using R to Analyze G1GC Log Files   Using R to Analyze G1GC Log Files Introduction Working in Oracle Platform Integration gives an engineer opportunities to work on a wide array of technologies. My team’s goal is to make Oracle applications run best on the Solaris/SPARC platform. When looking for bottlenecks in a modern applications, one needs to be aware of not only how the CPUs and operating system are executing, but also network, storage, and in some cases, the Java Virtual Machine. I was recently presented with about 1.5 GB of Java Garbage First Garbage Collector log file data. If you’re not familiar with the subject, you might want to review Garbage First Garbage Collector Tuning by Monica Beckwith. The customer had been running Java HotSpot 1.6.0_31 to host a web application server. I was told that the Solaris/SPARC server was running a Java process launched using a commmand line that included the following flags: -d64 -Xms9g -Xmx9g -XX:+UseG1GC -XX:MaxGCPauseMillis=200 -XX:InitiatingHeapOccupancyPercent=80 -XX:PermSize=256m -XX:MaxPermSize=256m -XX:+PrintGC -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC -XX:+PrintGCDateStamps -XX:+PrintFlagsFinal -XX:+DisableExplicitGC -XX:+UnlockExperimentalVMOptions -XX:ParallelGCThreads=8 Several sources on the internet indicate that if I were to print out the 1.5 GB of log files, it would require enough paper to fill the bed of a pick up truck. Of course, it would be fruitless to try to scan the log files by hand. Tools will be required to summarize the contents of the log files. Others have encountered large Java garbage collection log files. There are existing tools to analyze the log files: IBM’s GC toolkit The chewiebug GCViewer gchisto HPjmeter Instead of using one of the other tools listed, I decide to parse the log files with standard Unix tools, and analyze the data with R. Data Cleansing The log files arrived in two different formats. I guess that the difference is that one set of log files was generated using a more verbose option, maybe -XX:+PrintHeapAtGC, and the other set of log files was generated without that option. Format 1 In some of the log files, the log files with the less verbose format, a single trace, i.e. the report of a singe garbage collection event, looks like this: {Heap before GC invocations=12280 (full 61): garbage-first heap total 9437184K, used 7499918K [0xfffffffd00000000, 0xffffffff40000000, 0xffffffff40000000) region size 4096K, 1 young (4096K), 0 survivors (0K) compacting perm gen total 262144K, used 144077K [0xffffffff40000000, 0xffffffff50000000, 0xffffffff50000000) the space 262144K, 54% used [0xffffffff40000000, 0xffffffff48cb3758, 0xffffffff48cb3800, 0xffffffff50000000) No shared spaces configured. 2014-05-14T07:24:00.988-0700: 60586.353: [GC pause (young) 7324M->7320M(9216M), 0.1567265 secs] Heap after GC invocations=12281 (full 61): garbage-first heap total 9437184K, used 7496533K [0xfffffffd00000000, 0xffffffff40000000, 0xffffffff40000000) region size 4096K, 0 young (0K), 0 survivors (0K) compacting perm gen total 262144K, used 144077K [0xffffffff40000000, 0xffffffff50000000, 0xffffffff50000000) the space 262144K, 54% used [0xffffffff40000000, 0xffffffff48cb3758, 0xffffffff48cb3800, 0xffffffff50000000) No shared spaces configured. } A simple grep can be used to extract a summary: $ grep "\[ GC pause (young" g1gc.log 2014-05-13T13:24:35.091-0700: 3.109: [GC pause (young) 20M->5029K(9216M), 0.0146328 secs] 2014-05-13T13:24:35.440-0700: 3.459: [GC pause (young) 9125K->6077K(9216M), 0.0086723 secs] 2014-05-13T13:24:37.581-0700: 5.599: [GC pause (young) 25M->8470K(9216M), 0.0203820 secs] 2014-05-13T13:24:42.686-0700: 10.704: [GC pause (young) 44M->15M(9216M), 0.0288848 secs] 2014-05-13T13:24:48.941-0700: 16.958: [GC pause (young) 51M->20M(9216M), 0.0491244 secs] 2014-05-13T13:24:56.049-0700: 24.066: [GC pause (young) 92M->26M(9216M), 0.0525368 secs] 2014-05-13T13:25:34.368-0700: 62.383: [GC pause (young) 602M->68M(9216M), 0.1721173 secs] But that format wasn't easily read into R, so I needed to be a bit more tricky. I used the following Unix command to create a summary file that was easy for R to read. $ echo "SecondsSinceLaunch BeforeSize AfterSize TotalSize RealTime" $ grep "\[GC pause (young" g1gc.log | grep -v mark | sed -e 's/[A-SU-z\(\),]/ /g' -e 's/->/ /' -e 's/: / /g' | more SecondsSinceLaunch BeforeSize AfterSize TotalSize RealTime 2014-05-13T13:24:35.091-0700 3.109 20 5029 9216 0.0146328 2014-05-13T13:24:35.440-0700 3.459 9125 6077 9216 0.0086723 2014-05-13T13:24:37.581-0700 5.599 25 8470 9216 0.0203820 2014-05-13T13:24:42.686-0700 10.704 44 15 9216 0.0288848 2014-05-13T13:24:48.941-0700 16.958 51 20 9216 0.0491244 2014-05-13T13:24:56.049-0700 24.066 92 26 9216 0.0525368 2014-05-13T13:25:34.368-0700 62.383 602 68 9216 0.1721173 Format 2 In some of the log files, the log files with the more verbose format, a single trace, i.e. the report of a singe garbage collection event, was more complicated than Format 1. Here is a text file with an example of a single G1GC trace in the second format. As you can see, it is quite complicated. It is nice that there is so much information available, but the level of detail can be overwhelming. I wrote this awk script (download) to summarize each trace on a single line. #!/usr/bin/env awk -f BEGIN { printf("SecondsSinceLaunch IncrementalCount FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize\n") } ###################### # Save count data from lines that are at the start of each G1GC trace. # Each trace starts out like this: # {Heap before GC invocations=14 (full 0): # garbage-first heap total 9437184K, used 325496K [0xfffffffd00000000, 0xffffffff40000000, 0xffffffff40000000) ###################### /{Heap.*full/{ gsub ( "\\)" , "" ); nf=split($0,a,"="); split(a[2],b," "); getline; if ( match($0, "first") ) { G1GC=1; IncrementalCount=b[1]; FullCount=substr( b[3], 1, length(b[3])-1 ); } else { G1GC=0; } } ###################### # Pull out time stamps that are in lines with this format: # 2014-05-12T14:02:06.025-0700: 94.312: [GC pause (young), 0.08870154 secs] ###################### /GC pause/ { DateTime=$1; SecondsSinceLaunch=substr($2, 1, length($2)-1); } ###################### # Heap sizes are in lines that look like this: # [ 4842M->4838M(9216M)] ###################### /\[ .*]$/ { gsub ( "\\[" , "" ); gsub ( "\ \]" , "" ); gsub ( "->" , " " ); gsub ( "\\( " , " " ); gsub ( "\ \)" , " " ); split($0,a," "); if ( split(a[1],b,"M") > 1 ) {BeforeSize=b[1]*1024;} if ( split(a[1],b,"K") > 1 ) {BeforeSize=b[1];} if ( split(a[2],b,"M") > 1 ) {AfterSize=b[1]*1024;} if ( split(a[2],b,"K") > 1 ) {AfterSize=b[1];} if ( split(a[3],b,"M") > 1 ) {TotalSize=b[1]*1024;} if ( split(a[3],b,"K") > 1 ) {TotalSize=b[1];} } ###################### # Emit an output line when you find input that looks like this: # [Times: user=1.41 sys=0.08, real=0.24 secs] ###################### /\[Times/ { if (G1GC==1) { gsub ( "," , "" ); split($2,a,"="); UserTime=a[2]; split($3,a,"="); SysTime=a[2]; split($4,a,"="); RealTime=a[2]; print DateTime,SecondsSinceLaunch,IncrementalCount,FullCount,UserTime,SysTime,RealTime,BeforeSize,AfterSize,TotalSize; G1GC=0; } } The resulting summary is about 25X smaller that the original file, but still difficult for a human to digest. SecondsSinceLaunch IncrementalCount FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize ... 2014-05-12T18:36:34.669-0700: 3985.744 561 0 0.57 0.06 0.16 1724416 1720320 9437184 2014-05-12T18:36:34.839-0700: 3985.914 562 0 0.51 0.06 0.19 1724416 1720320 9437184 2014-05-12T18:36:35.069-0700: 3986.144 563 0 0.60 0.04 0.27 1724416 1721344 9437184 2014-05-12T18:36:35.354-0700: 3986.429 564 0 0.33 0.04 0.09 1725440 1722368 9437184 2014-05-12T18:36:35.545-0700: 3986.620 565 0 0.58 0.04 0.17 1726464 1722368 9437184 2014-05-12T18:36:35.726-0700: 3986.801 566 0 0.43 0.05 0.12 1726464 1722368 9437184 2014-05-12T18:36:35.856-0700: 3986.930 567 0 0.30 0.04 0.07 1726464 1723392 9437184 2014-05-12T18:36:35.947-0700: 3987.023 568 0 0.61 0.04 0.26 1727488 1723392 9437184 2014-05-12T18:36:36.228-0700: 3987.302 569 0 0.46 0.04 0.16 1731584 1724416 9437184 Reading the Data into R Once the GC log data had been cleansed, either by processing the first format with the shell script, or by processing the second format with the awk script, it was easy to read the data into R. g1gc.df = read.csv("summary.txt", row.names = NULL, stringsAsFactors=FALSE,sep="") str(g1gc.df) ## 'data.frame': 8307 obs. of 10 variables: ## $ row.names : chr "2014-05-12T14:00:32.868-0700:" "2014-05-12T14:00:33.179-0700:" "2014-05-12T14:00:33.677-0700:" "2014-05-12T14:00:35.538-0700:" ... ## $ SecondsSinceLaunch: num 1.16 1.47 1.97 3.83 6.1 ... ## $ IncrementalCount : int 0 1 2 3 4 5 6 7 8 9 ... ## $ FullCount : int 0 0 0 0 0 0 0 0 0 0 ... ## $ UserTime : num 0.11 0.05 0.04 0.21 0.08 0.26 0.31 0.33 0.34 0.56 ... ## $ SysTime : num 0.04 0.01 0.01 0.05 0.01 0.06 0.07 0.06 0.07 0.09 ... ## $ RealTime : num 0.02 0.02 0.01 0.04 0.02 0.04 0.05 0.04 0.04 0.06 ... ## $ BeforeSize : int 8192 5496 5768 22528 24576 43008 34816 53248 55296 93184 ... ## $ AfterSize : int 1400 1672 2557 4907 7072 14336 16384 18432 19456 21504 ... ## $ TotalSize : int 9437184 9437184 9437184 9437184 9437184 9437184 9437184 9437184 9437184 9437184 ... head(g1gc.df) ## row.names SecondsSinceLaunch IncrementalCount ## 1 2014-05-12T14:00:32.868-0700: 1.161 0 ## 2 2014-05-12T14:00:33.179-0700: 1.472 1 ## 3 2014-05-12T14:00:33.677-0700: 1.969 2 ## 4 2014-05-12T14:00:35.538-0700: 3.830 3 ## 5 2014-05-12T14:00:37.811-0700: 6.103 4 ## 6 2014-05-12T14:00:41.428-0700: 9.720 5 ## FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize ## 1 0 0.11 0.04 0.02 8192 1400 9437184 ## 2 0 0.05 0.01 0.02 5496 1672 9437184 ## 3 0 0.04 0.01 0.01 5768 2557 9437184 ## 4 0 0.21 0.05 0.04 22528 4907 9437184 ## 5 0 0.08 0.01 0.02 24576 7072 9437184 ## 6 0 0.26 0.06 0.04 43008 14336 9437184 Basic Statistics Once the data has been read into R, simple statistics are very easy to generate. All of the numbers from high school statistics are available via simple commands. For example, generate a summary of every column: summary(g1gc.df) ## row.names SecondsSinceLaunch IncrementalCount FullCount ## Length:8307 Min. : 1 Min. : 0 Min. : 0.0 ## Class :character 1st Qu.: 9977 1st Qu.:2048 1st Qu.: 0.0 ## Mode :character Median :12855 Median :4136 Median : 12.0 ## Mean :12527 Mean :4156 Mean : 31.6 ## 3rd Qu.:15758 3rd Qu.:6262 3rd Qu.: 61.0 ## Max. :55484 Max. :8391 Max. :113.0 ## UserTime SysTime RealTime BeforeSize ## Min. :0.040 Min. :0.0000 Min. : 0.0 Min. : 5476 ## 1st Qu.:0.470 1st Qu.:0.0300 1st Qu.: 0.1 1st Qu.:5137920 ## Median :0.620 Median :0.0300 Median : 0.1 Median :6574080 ## Mean :0.751 Mean :0.0355 Mean : 0.3 Mean :5841855 ## 3rd Qu.:0.920 3rd Qu.:0.0400 3rd Qu.: 0.2 3rd Qu.:7084032 ## Max. :3.370 Max. :1.5600 Max. :488.1 Max. :8696832 ## AfterSize TotalSize ## Min. : 1380 Min. :9437184 ## 1st Qu.:5002752 1st Qu.:9437184 ## Median :6559744 Median :9437184 ## Mean :5785454 Mean :9437184 ## 3rd Qu.:7054336 3rd Qu.:9437184 ## Max. :8482816 Max. :9437184 Q: What is the total amount of User CPU time spent in garbage collection? sum(g1gc.df$UserTime) ## [1] 6236 As you can see, less than two hours of CPU time was spent in garbage collection. Is that too much? To find the percentage of time spent in garbage collection, divide the number above by total_elapsed_time*CPU_count. In this case, there are a lot of CPU’s and it turns out the the overall amount of CPU time spent in garbage collection isn’t a problem when viewed in isolation. When calculating rates, i.e. events per unit time, you need to ask yourself if the rate is homogenous across the time period in the log file. Does the log file include spikes of high activity that should be separately analyzed? Averaging in data from nights and weekends with data from business hours may alias problems. If you have a reason to suspect that the garbage collection rates include peaks and valleys that need independent analysis, see the “Time Series” section, below. Q: How much garbage is collected on each pass? The amount of heap space that is recovered per GC pass is surprisingly low: At least one collection didn’t recover any data. (“Min.=0”) 25% of the passes recovered 3MB or less. (“1st Qu.=3072”) Half of the GC passes recovered 4MB or less. (“Median=4096”) The average amount recovered was 56MB. (“Mean=56390”) 75% of the passes recovered 36MB or less. (“3rd Qu.=36860”) At least one pass recovered 2GB. (“Max.=2121000”) g1gc.df$Delta = g1gc.df$BeforeSize - g1gc.df$AfterSize summary(g1gc.df$Delta) ## Min. 1st Qu. Median Mean 3rd Qu. Max. ## 0 3070 4100 56400 36900 2120000 Q: What is the maximum User CPU time for a single collection? The worst garbage collection (“Max.”) is many standard deviations away from the mean. The data appears to be right skewed. summary(g1gc.df$UserTime) ## Min. 1st Qu. Median Mean 3rd Qu. Max. ## 0.040 0.470 0.620 0.751 0.920 3.370 sd(g1gc.df$UserTime) ## [1] 0.3966 Basic Graphics Once the data is in R, it is trivial to plot the data with formats including dot plots, line charts, bar charts (simple, stacked, grouped), pie charts, boxplots, scatter plots histograms, and kernel density plots. Histogram of User CPU Time per Collection I don't think that this graph requires any explanation. hist(g1gc.df$UserTime, main="User CPU Time per Collection", xlab="Seconds", ylab="Frequency") Box plot to identify outliers When the initial data is viewed with a box plot, you can see the one crazy outlier in the real time per GC. Save this data point for future analysis and drop the outlier so that it’s not throwing off our statistics. Now the box plot shows many outliers, which will be examined later, using times series analysis. Notice that the scale of the x-axis changes drastically once the crazy outlier is removed. par(mfrow=c(2,1)) boxplot(g1gc.df$UserTime,g1gc.df$SysTime,g1gc.df$RealTime, main="Box Plot of Time per GC\n(dominated by a crazy outlier)", names=c("usr","sys","elapsed"), xlab="Seconds per GC", ylab="Time (Seconds)", horizontal = TRUE, outcol="red") crazy.outlier.df=g1gc.df[g1gc.df$RealTime > 400,] g1gc.df=g1gc.df[g1gc.df$RealTime < 400,] boxplot(g1gc.df$UserTime,g1gc.df$SysTime,g1gc.df$RealTime, main="Box Plot of Time per GC\n(crazy outlier excluded)", names=c("usr","sys","elapsed"), xlab="Seconds per GC", ylab="Time (Seconds)", horizontal = TRUE, outcol="red") box(which = "outer", lty = "solid") Here is the crazy outlier for future analysis: crazy.outlier.df ## row.names SecondsSinceLaunch IncrementalCount ## 8233 2014-05-12T23:15:43.903-0700: 20741 8316 ## FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize ## 8233 112 0.55 0.42 488.1 8381440 8235008 9437184 ## Delta ## 8233 146432 R Time Series Data To analyze the garbage collection as a time series, I’ll use Z’s Ordered Observations (zoo). “zoo is the creator for an S3 class of indexed totally ordered observations which includes irregular time series.” require(zoo) ## Loading required package: zoo ## ## Attaching package: 'zoo' ## ## The following objects are masked from 'package:base': ## ## as.Date, as.Date.numeric head(g1gc.df[,1]) ## [1] "2014-05-12T14:00:32.868-0700:" "2014-05-12T14:00:33.179-0700:" ## [3] "2014-05-12T14:00:33.677-0700:" "2014-05-12T14:00:35.538-0700:" ## [5] "2014-05-12T14:00:37.811-0700:" "2014-05-12T14:00:41.428-0700:" options("digits.secs"=3) times=as.POSIXct( g1gc.df[,1], format="%Y-%m-%dT%H:%M:%OS%z:") g1gc.z = zoo(g1gc.df[,-c(1)], order.by=times) head(g1gc.z) ## SecondsSinceLaunch IncrementalCount FullCount ## 2014-05-12 17:00:32.868 1.161 0 0 ## 2014-05-12 17:00:33.178 1.472 1 0 ## 2014-05-12 17:00:33.677 1.969 2 0 ## 2014-05-12 17:00:35.538 3.830 3 0 ## 2014-05-12 17:00:37.811 6.103 4 0 ## 2014-05-12 17:00:41.427 9.720 5 0 ## UserTime SysTime RealTime BeforeSize AfterSize ## 2014-05-12 17:00:32.868 0.11 0.04 0.02 8192 1400 ## 2014-05-12 17:00:33.178 0.05 0.01 0.02 5496 1672 ## 2014-05-12 17:00:33.677 0.04 0.01 0.01 5768 2557 ## 2014-05-12 17:00:35.538 0.21 0.05 0.04 22528 4907 ## 2014-05-12 17:00:37.811 0.08 0.01 0.02 24576 7072 ## 2014-05-12 17:00:41.427 0.26 0.06 0.04 43008 14336 ## TotalSize Delta ## 2014-05-12 17:00:32.868 9437184 6792 ## 2014-05-12 17:00:33.178 9437184 3824 ## 2014-05-12 17:00:33.677 9437184 3211 ## 2014-05-12 17:00:35.538 9437184 17621 ## 2014-05-12 17:00:37.811 9437184 17504 ## 2014-05-12 17:00:41.427 9437184 28672 Example of Two Benchmark Runs in One Log File The data in the following graph is from a different log file, not the one of primary interest to this article. I’m including this image because it is an example of idle periods followed by busy periods. It would be uninteresting to average the rate of garbage collection over the entire log file period. More interesting would be the rate of garbage collect in the two busy periods. Are they the same or different? Your production data may be similar, for example, bursts when employees return from lunch and idle times on weekend evenings, etc. Once the data is in an R Time Series, you can analyze isolated time windows. Clipping the Time Series data Flashing back to our test case… Viewing the data as a time series is interesting. You can see that the work intensive time period is between 9:00 PM and 3:00 AM. Lets clip the data to the interesting period:     par(mfrow=c(2,1)) plot(g1gc.z$UserTime, type="h", main="User Time per GC\nTime: Complete Log File", xlab="Time of Day", ylab="CPU Seconds per GC", col="#1b9e77") clipped.g1gc.z=window(g1gc.z, start=as.POSIXct("2014-05-12 21:00:00"), end=as.POSIXct("2014-05-13 03:00:00")) plot(clipped.g1gc.z$UserTime, type="h", main="User Time per GC\nTime: Limited to Benchmark Execution", xlab="Time of Day", ylab="CPU Seconds per GC", col="#1b9e77") box(which = "outer", lty = "solid") Cumulative Incremental and Full GC count Here is the cumulative incremental and full GC count. When the line is very steep, it indicates that the GCs are repeating very quickly. Notice that the scale on the Y axis is different for full vs. incremental. plot(clipped.g1gc.z[,c(2:3)], main="Cumulative Incremental and Full GC count", xlab="Time of Day", col="#1b9e77") GC Analysis of Benchmark Execution using Time Series data In the following series of 3 graphs: The “After Size” show the amount of heap space in use after each garbage collection. Many Java objects are still referenced, i.e. alive, during each garbage collection. This may indicate that the application has a memory leak, or may indicate that the application has a very large memory footprint. Typically, an application's memory footprint plateau's in the early stage of execution. One would expect this graph to have a flat top. The steep decline in the heap space may indicate that the application crashed after 2:00. The second graph shows that the outliers in real execution time, discussed above, occur near 2:00. when the Java heap seems to be quite full. The third graph shows that Full GCs are infrequent during the first few hours of execution. The rate of Full GC's, (the slope of the cummulative Full GC line), changes near midnight.   plot(clipped.g1gc.z[,c("AfterSize","RealTime","FullCount")], xlab="Time of Day", col=c("#1b9e77","red","#1b9e77")) GC Analysis of heap recovered Each GC trace includes the amount of heap space in use before and after the individual GC event. During garbage coolection, unreferenced objects are identified, the space holding the unreferenced objects is freed, and thus, the difference in before and after usage indicates how much space has been freed. The following box plot and bar chart both demonstrate the same point - the amount of heap space freed per garbage colloection is surprisingly low. par(mfrow=c(2,1)) boxplot(as.vector(clipped.g1gc.z$Delta), main="Amount of Heap Recovered per GC Pass", xlab="Size in KB", horizontal = TRUE, col="red") hist(as.vector(clipped.g1gc.z$Delta), main="Amount of Heap Recovered per GC Pass", xlab="Size in KB", breaks=100, col="red") box(which = "outer", lty = "solid") This graph is the most interesting. The dark blue area shows how much heap is occupied by referenced Java objects. This represents memory that holds live data. The red fringe at the top shows how much data was recovered after each garbage collection. barplot(clipped.g1gc.z[,c("AfterSize","Delta")], col=c("#7570b3","#e7298a"), xlab="Time of Day", border=NA) legend("topleft", c("Live Objects","Heap Recovered on GC"), fill=c("#7570b3","#e7298a")) box(which = "outer", lty = "solid") When I discuss the data in the log files with the customer, I will ask for an explaination for the large amount of referenced data resident in the Java heap. There are two are posibilities: There is a memory leak and the amount of space required to hold referenced objects will continue to grow, limited only by the maximum heap size. After the maximum heap size is reached, the JVM will throw an “Out of Memory” exception every time that the application tries to allocate a new object. If this is the case, the aplication needs to be debugged to identify why old objects are referenced when they are no longer needed. The application has a legitimate requirement to keep a large amount of data in memory. The customer may want to further increase the maximum heap size. Another possible solution would be to partition the application across multiple cluster nodes, where each node has responsibility for managing a unique subset of the data. Conclusion In conclusion, R is a very powerful tool for the analysis of Java garbage collection log files. The primary difficulty is data cleansing so that information can be read into an R data frame. Once the data has been read into R, a rich set of tools may be used for thorough evaluation.

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  • Separating null byte separated UNICODE C string.

    - by Ramblingwood
    First off, this is NOT a duplicate of: http://stackoverflow.com/questions/1911053/turn-a-c-string-with-null-bytes-into-a-char-array , because the given answer doesn't work when the char *'s are Unicode. I think the problem is that because I am trying to use Unicode and thus wchar_t instead of char, the length of each character is different and thus, this doesn't work (it does in non-unicode): char *Buffer; // your null-separated strings char *Current; // Pointer to the current string // [...] for (Current = Buffer; *Current; Current += strlen(Current) + 1) printf("GetOpenFileName returned: %s\n", Current); Does anyone have a similar solution that works on Unicode strings? I have been banging my head on the this for over 4 hours now. C doesn't agree with me.

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  • Undefined reference to ...

    - by Patrick LaChance
    I keep getting this error message every time I try to compile, and I cannot find out what the problem is. any help would be greatly appreciated: C:\DOCUME~1\Patrick\LOCALS~1\Temp/ccL92mj9.o:main.cpp:(.txt+0x184): undefined reference to 'List::List()' C:\DOCUME~1\Patrick\LOCALS~1\Temp/ccL92mj9.o:main.cpp:(.txt+0x184): undefined reference to 'List::add(int)' collect2: ld returned 1 exit status code: //List.h #ifndef LIST_H #define LIST_H #include <exception> //brief Definition of linked list class class List { public: /** \brief Exception for operating on empty list */ class Empty : public std::exception { public: virtual const char* what() const throw(); }; /** \brief Exception for invalid operations other than operating on an empty list */ class InvalidOperation : public std::exception { public: virtual const char* what() const throw(); }; /** \brief Node within List */ class Node { public: /** data element stored in this node */ int element; /** next node in list */ Node* next; /** previous node in list */ Node* previous; Node (int element); ~Node(); void print() const; void printDebug() const; }; List(); ~List(); void add(int element); void remove(int element); int first()const; int last()const; int removeFirst(); int removeLast(); bool isEmpty()const; int size()const; void printForward() const; void printReverse() const; void printDebug() const; /** enables extra output for debugging purposes */ static bool traceOn; private: /** head of list */ Node* head; /** tail of list */ Node* tail; /** count of number of nodes */ int count; }; #endif //List.cpp I only included the parts of List.cpp that might be the issue #include "List.h" #include <iostream> #include <iomanip> using namespace std; List::List() { //List::size = NULL; head = NULL; tail = NULL; } List::~List() { Node* current; while(head != NULL) { current = head-> next; delete current->previous; if (current->next!=NULL) { head = current; } else { delete current; } } } void List::add(int element) { Node* newNode; Node* current; newNode->element = element; if(newNode->element > head->element) { current = head->next; } else { head->previous = newNode; newNode->next = head; newNode->previous = NULL; return; } while(newNode->element > current->element) { current = current->next; } if(newNode->element <= current->element) { newNode->previous = current->previous; newNode->next = current; } } //main.cpp #include "List.h" #include <iostream> #include <string> using namespace std; //void add(int element); int main (char** argv, int argc) { List* MyList = new List(); bool quit = false; string value; int element; while(quit==false) { cin>>value; if(value == "add") { cin>>element; MyList->add(element); } if(value=="quit") { quit = true; } } return 0; } I'm doing everything I think I'm suppose to be doing. main.cpp isn't complete yet, just trying to get the add function to work first. Any help will be greatly appreciated.

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  • Conditional jump or move depends on uninitialised value - freeing a linked list

    - by user720491
    I want to free a linked list in C. All is working fine, but Valgrind is telling me Conditional jump or move depends on uninitialised value(s) at 0x401400: mtf_destroy Here's the code: list_elt *head; void mtf_init() { list_elt *current; head = malloc(sizeof(list_elt)); current = head; for (int i = 0; i < LIST_SIZE-1; i++) { current->value = (BYTE) i; current->next = malloc(sizeof(list_elt)); current = current->next; } current->value = LIST_SIZE-1; } void mtf_destroy(list_elt *elt) { if (elt->next != NULL) mtf_destroy(elt->next); free(elt); } How can I solve this? Thanks!

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  • I just restarted Apache and now the server is down

    - by James
    I am pretty terrified right now. I'm scared I'm going to get a call in a couple minutes from a hundred people saying the website doesn't work. I was at the terminal changing some configuration files when I went to restart the server to update the .conf files with this command: /etc/init.d/apache2 graceful After I ran that, none of the websites work and I have no idea what to do. There are about 100 errors I am getting according to the log files. They all begin with "PHP Notice" and most relate to "use of undefined constant" Also, I just spoke with a coworker, describing what I did, and he noticed that there are two installations of apache on the server and that I restarted the one that we don't use. This is what the error log says (assuming it's the correct error log): [Wed Jan 05 11:52:06 2011] [notice] Graceful restart requested, doing restart Warning: DocumentRoot [/u/apps/staging/antetr/current/public/] does not exist [Wed Jan 05 11:52:08 2011] [warn] NameVirtualHost *:80 has no VirtualHosts (98)Address already in use: make_sock: could not bind to address [::]:80 (98)Address already in use: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting down Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs FINAL UPDATE: Ok, I fixed it. The problem was (as you experts facepalming probably know) that it couldn't access an error log in the directory I was working in. I created an empty error log file and tried the restart command again and now all the sites are back up... Though my original problem is still there.. Thanks to all those who offered advice, it really helped and let me breathe for a moment.

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  • I just restarted Apache and now the server is down

    - by James
    I am pretty terrified right now. I'm scared I'm going to get a call in a couple minutes from a hundred people saying the website doesn't work. I was at the terminal changing some configuration files when I went to restart the server to update the .conf files with this command: /etc/init.d/apache2 graceful After I ran that, none of the websites work and I have no idea what to do. There are about 100 errors I am getting according to the log files. They all begin with "PHP Notice" and most relate to "use of undefined constant" Also, I just spoke with a coworker, describing what I did, and he noticed that there are two installations of apache on the server and that I restarted the one that we don't use. This is what the error log says (assuming it's the correct error log): [Wed Jan 05 11:52:06 2011] [notice] Graceful restart requested, doing restart Warning: DocumentRoot [/u/apps/staging/antetr/current/public/] does not exist [Wed Jan 05 11:52:08 2011] [warn] NameVirtualHost *:80 has no VirtualHosts (98)Address already in use: make_sock: could not bind to address [::]:80 (98)Address already in use: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting down Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs (2)No such file or directory: apache2: could not open error log file /u/apps/production/madfilmdash/current/log/apache-error.log. Unable to open logs FINAL UPDATE: Ok, I fixed it. The problem was (as you experts facepalming probably know) that it couldn't access an error log in the directory I was working in. I created an empty error log file and tried the restart command again and now all the sites are back up... Though my original problem is still there.. Thanks to all those who offered advice, it really helped and let me breathe for a moment.

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