Search Results

Search found 32994 results on 1320 pages for 'second level cache'.

Page 228/1320 | < Previous Page | 224 225 226 227 228 229 230 231 232 233 234 235  | Next Page >

  • Dynamically created image doesn't show when <img>'s src is refreshed to point to it

    - by Obay
    Hello, I have a javascript function generateGraph() { ... jQuery.get('chart.php?month='+month+'&year='+year); document.getElementById('graph').src = 'charts/'+month+'_'+year+'.png'; ... } which is called onChange. It basically creates, if not exists, or refreshes if already exists, a PNG image (using the first line above) and supposedly displays the generated image (using the second line above). The first line works, but the second one doesn't. Meaning, the image is generated, but the second line can't display the image, unless the page is reloaded, or if the image being referred to already existed before the page was loaded (meaning the 1st line just "refreshed" the image) Any ideas as to why this is and how to fix it? Thanks much for your help in advance!

    Read the article

  • How do I use timezones with a datetime object in python?

    - by jidar
    How do I properly represent a different timezone in my timezone? The below example only works because I know that EDT is one hour ahead of me, so I can uncomment the subtraction of myTimeZone() import datetime, re from datetime import tzinfo class myTimeZone(tzinfo): """docstring for myTimeZone""" def utfoffset(self, dt): return timedelta(hours=1) def myDateHandler(aDateString): """u'Sat, 6 Sep 2008 21:16:33 EDT'""" _my_date_pattern = re.compile(r'\w+\,\s+(\d+)\s+(\w+)\s+(\d+)\s+(\d+)\:(\d+)\:(\d+)') day, month, year, hour, minute, second = _my_date_pattern.search(aDateString).groups() month = [ 'JAN', 'FEB', 'MAR', 'APR', 'MAY', 'JUN', 'JUL', 'AUG', 'SEP', 'OCT', 'NOV', 'DEC' ].index(month.upper()) + 1 dt = datetime.datetime( int(year), int(month), int(day), int(hour), int(minute), int(second) ) # dt = dt - datetime.timedelta(hours=1) # dt = dt - dt.tzinfo.utfoffset(myTimeZone()) return (dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, 0, 0, 0) def main(): print myDateHandler("Sat, 6 Sep 2008 21:16:33 EDT") if __name__ == '__main__': main()

    Read the article

  • C -Segmentation fault !

    - by FILIaS
    It seems at least weird to me... The program runs normally.But after I call the enter() function for the 4th time,there is a segmentation fault!I would appreciate any help. With the following function enter() I wanna add user commands' datas to a list. [Some part of the code is already posted on another question of me, but I think I should post it again...as it's a different problem I'm facing now.] /* struct for all the datas that user enters on file*/ typedef struct catalog { char short_name[50]; char surname[50]; signed int amount; char description[1000]; struct catalog *next; }catalog,*catalogPointer; catalogPointer current; catalogPointer head = NULL; void enter(void) //user command: i <name> <surname> <amount> <description> { int n,j=2,k=0; char temp[1500]; char *short_name,*surname,*description; signed int amount; char* params = strchr(command,' ') + 1; //strchr returns a pointer to the 1st space on the command.U want a pointer to the char right after that space. strcpy(temp, params); //params is saved as temp. char *curToken = strtok(temp," "); //strtok cuts 'temp' into strings between the spaces and saves them to 'curToken' printf("temp is:%s \n",temp); printf("\nWhat you entered for saving:\n"); for (n = 0; curToken; ++n) //until curToken ends: { if (curToken) { short_name = malloc(strlen(curToken) + 1); strncpy(short_name, curToken, sizeof (short_name)); } printf("Short Name: %s \n",short_name); curToken = strtok(NULL," "); if (curToken) { surname = malloc(strlen(curToken) + 1); strncpy(surname, curToken,sizeof (surname)); } printf("SurName: %s \n",surname); curToken = strtok(NULL," "); if (curToken) { //int * amount= malloc(sizeof (signed int *)); char *chk; amount = (int) strtol(curToken, &chk, 10); if (!isspace(*chk) && *chk != 0) fprintf(stderr,"Warning: expected integer value for amount, received %s instead\n",curToken); } printf("Amount: %d \n",amount); curToken = strtok(NULL,"\0"); if (curToken) { description = malloc(strlen(curToken) + 1); strncpy(description, curToken, sizeof (description)); } printf("Description: %s \n",description); break; } if (findEntryExists(head, surname,short_name) != NULL) //call function in order to see if entry exists already on the catalog printf("\nAn entry for <%s %s> is already in the catalog!\nNew entry not entered.\n",short_name,surname); else { printf("\nTry to entry <%s %s %d %s> in the catalog list!\n",short_name,surname,amount,description); newEntry(&head,short_name,surname,amount,description); printf("\n**Entry done!**\n"); } // Maintain the list in alphabetical order by surname. } catalogPointer findEntryExists (catalogPointer head, char num[],char first[]) { catalogPointer p = head; while (p != NULL && strcmp(p->surname, num) != 0 && strcmp(p->short_name,first) != 0) { p = p->next; } return p; } catalogPointer newEntry (catalog** headRef,char short_name[], char surname[], signed int amount, char description[]) { catalogPointer newNode = (catalogPointer)malloc(sizeof(catalog)); catalogPointer first; catalogPointer second; catalogPointer tmp; first=head; second=NULL; strcpy(newNode->short_name, short_name); strcpy(newNode->surname, surname); newNode->amount=amount; strcpy(newNode->description, description); while (first!=NULL) { if (strcmp(surname,first->surname)>0) second=first; else if (strcmp(surname,first->surname)==0) { if (strcmp(short_name,first->short_name)>0) second=first; } first=first->next; } if (second==NULL) { newNode->next=head; head=newNode; } else //SEGMENTATION APPEARS WHEN IT GETS HERE! { tmp=second->next; newNode->next=tmp; first->next=newNode; } } UPDATE: SegFault appears only when it gets on the 'else' loop of InsertSort() function. I observed that segmentation fault appears when i try to put on the list names that are after it. For example, if in the list exists: [Name:b Surname:b Amount:6 Description:b] [Name:c Surname:c Amount:5 Description:c] [Name:d Surname:d Amount:4 Description:d] [Name:e Surname:e Amount:3 Description:e] [Name:g Surname:g Amount:2 Description:g] [Name:x Surname:x Amount:1 Description:x] and i put: " x z 77 gege" there is a segmentation but if i put "x a 77 gege" it continues normally....

    Read the article

  • no Jquery only Javascrip fadein function with cleartype fot text

    - by Chetan
    Sorry guys.. I am not familiar with JavaScrip anymore but I need to add clear type of some thing which can make text anti-aliased in IE7 browser. My script as follow // JavaScript Document var CurrentDivIndex=0; var TimeOutValue; var btn; var TimeToFade = 1000.0; function ShowDivSlideShow() { try { if(CurrentDivIndex == 5) CurrentDivIndex=0; CurrentDivIndex++; //alert("Banner" + CurrentDivIndex); //alert(CurrentDivIndex); var Indexer=1; while(Indexer<6) { var DivToShow=document.getElementById("Banner" + Indexer); DivToShow.style.display = "none"; btn=document.getElementById("btnb" + Indexer); btn.setAttribute("class","none"); Indexer++; } var DivToShow=document.getElementById("Banner" + CurrentDivIndex); DivToShow.style.display = "block"; btn=document.getElementById("btnb" + CurrentDivIndex); btn.setAttribute("class","activeSlide"); // btn.className="activeSlide"; fadeIn(); TimeOutValue=setTimeout("ShowDivSlideShow()",6000); } catch(err) { alert(err) } } function ShowCustomDiv(CurrentDivIndexRec) { clearTimeout(TimeOutValue) CurrentDivIndex=CurrentDivIndexRec var Indexer=1; while(Indexer<6) { if(CurrentDivIndex==Indexer) { Indexer++; continue; } var DivToShow=document.getElementById("Banner" + Indexer); DivToShow.style.display = "none"; btn=document.getElementById("btnb" + Indexer); btn.setAttribute("class","none"); Indexer++; } var DivToShow=document.getElementById("Banner" + CurrentDivIndex); DivToShow.style.display = "block"; btn=document.getElementById("btnb" + CurrentDivIndex); btn.setAttribute("class","activeSlide"); btn.className="activeSlide" fadeIn(); } function ShowDivSlideShowWithTimeOut(CurrentDivIndexRec) { clearTimeout(TimeOutValue) CurrentDivIndex=CurrentDivIndexRec; var Indexer=1; while(Indexer<6) { if(CurrentDivIndex==Indexer) { Indexer++; continue; } var DivToShow=document.getElementById("Banner" + Indexer); DivToShow.style.display = "none"; btn=document.getElementById("btnb" + Indexer); btn.setAttribute("class","none"); Indexer++; } var DivToShow=document.getElementById("Banner" + CurrentDivIndexRec); DivToShow.style.display = "block"; btn=document.getElementById("btnb" + CurrentDivIndexRec); btn.setAttribute("class","activeSlide"); TimeOutValue=setTimeout("ShowDivSlideShow()",6000); } function ShowCustomDivOnClick(CurrentDivIndexRec) { clearTimeout(TimeOutValue) CurrentDivIndex=CurrentDivIndexRec; var Indexer=1; while(Indexer<6) { if(CurrentDivIndex==Indexer) { Indexer++; continue; } var DivToShow=document.getElementById("Banner" + Indexer); DivToShow.style.display = "none"; btn=document.getElementById("btnb" + Indexer); btn.setAttribute("class","none"); Indexer++; } var DivToShow=document.getElementById("Banner" + CurrentDivIndexRec); DivToShow.style.display = "block"; btn=document.getElementById("btnb" + CurrentDivIndexRec); btn.setAttribute("class","activeSlide"); fadeIn(); TimeOutValue=setTimeout("ShowDivSlideShow()",6000); } function setOpacity(level) { element=document.getElementById("Banner" + CurrentDivIndex); element.style.opacity = level; element.style.MozOpacity = level; element.style.KhtmlOpacity = level; element.style.filter = "alpha(opacity=" + (level * 100) + ");"; } var duration = 300; /* 1000 millisecond fade = 1 sec */ var steps = 10; /* number of opacity intervals */ var delay = 6000; /* 5 sec delay before fading out */ function fadeIn(){ for (i = 0; i <= 1; i += (1 / steps)) { setTimeout("setOpacity(" + i + ")", i * duration); } // setTimeout("fadeOut()", delay); } function fadeOut() { for (i = 0; i <= 1; i += (1 / steps)) { setTimeout("setOpacity(" + (1 - i) + ")", i * duration); } setTimeout("fadeIn()", duration); } //end of script Now I am very confused where to add : $('#slideshow').cycle({ cleartype: 1 // enable cleartype corrections }); or $('#fadingElement').fadeIn(2000, function(){ $(this).css('filter',''); }); so it will work... Please Help me...

    Read the article

  • Entity Framework doesn't like 0..1 to * relationships.

    - by Orion Adrian
    I have a database framework where I have two tables. The first table has a single column that is an identity and primary key. The second table contains two columns. One is a nvarchar primary key and the other is a nullable foreign key to the first table. On the default import of the database I get the following error: Condition cannot be specified for Column member 'ForeignKeyId' because it is marked with a 'Computed' or 'Identity' StoreGeneratedPattern. where ForeignKeyId is the second foreign key reference in the second table. Is this just something the entity model doesn't do? Or am I missing something?

    Read the article

  • WCF Callback Contract Fiddler Debugging

    - by DavyMac23
    I'm trying to debug a WCF self-hosted service utilizing callbacks. Every 1/2 I make a callback to a SL3 app to display the latest changes (yes, there are tons of changes every 1/2 second). There are 3 services, one has new data every 1/2 second, one has new data every second, and another has new data every hour. I've set all of my timeouts, Send, Receive, Open and Close to 2 days 23 hours and 23 minutes, but I still get time out errors on the service side when I go to issue the callback. I'm using Fiddler and I notice that my service that has new data every hour is still showing up every 10 seconds. Fiddlier shows a Body length of -1, then 10 seconds later it changes to 0 and the response is HTTP 200, but the overall elapsed time is 10 seconds. What's going on here?

    Read the article

  • JavaScript: 2 window.opener.location.href statements with alert() in between not functioning

    - by vastbeyond
    I need to make a little JS app to scroll automatically through a list of URLs. I've chosen to have the functionality in a pop-up, for various reasons. The syntax to change the opening window's URL is: window.opener.location.href = "http://www.example.com"; This works fine with one URL, but if two statements are called, only one is executed. I experimented with an alert statement between two of the above statements, and the alert event made the second statement function properly: window.opener.location.href = "http://www.example1.com"; alert("hello world"); window.opener.location.href = "http://www.example2.com"; Question is: does anyone know how to get the first and second window.opener statements to work, without the intervening alert();? Also, how can I add a pause between the two statements, so that the second executes a couple of seconds after the first? Thanks so much!

    Read the article

  • What is the fastest way to trim blank lines from beginning and end of array?

    - by Edward Tanguay
    This script: <?php $lines[] = ''; $lines[] = 'first line '; $lines[] = 'second line '; $lines[] = ''; $lines[] = 'fourth line'; $lines[] = ''; $lines[] = ''; $lineCount = 1; foreach($lines as $line) { echo $lineCount . ': [' . trim($line) . ']<br/>'; $lineCount++; } ?> produces this output: 1: [] 2: [first line] 3: [second line] 4: [] 5: [fourth line] 6: [] 7: [] What is the fastest, most efficient way to change the above script so that it also deletes the preceding and trailing blank entries but not the interior blank entries so that it outputs this: 1: [first line] 2: [second line] 3: [] 4: [fourth line] I could use the foreach loop but I imagine there is a way with array_filter or something similar which is much more efficient.

    Read the article

  • Randomized experiments in R

    - by gd047
    Here is a simple randomized experiment. In the following code I calculate the p-value under the null hypothesis that two different fertilizers applied to tomato plants have no effect in plants yields. The first random sample (x) comes from plants where a standard fertilizer has been used, while an "improved" one has been used in the plants where the second sample (y) comes from. x <- c(11.4,25.3,29.9,16.5,21.1) y <- c(23.7,26.6,28.5,14.2,17.9,24.3) total <- c(x,y) first <- combn(total,length(x)) second <- apply(first,2,function(x) total[!total %in% x]) dif.treat <- apply(second,2,mean) - apply(first,2,mean) # the first element of dif.treat is the one that I'm interested in (p.value <- length(dif.treat[dif.treat >= dif.treat[1]]) / length(dif.treat)) Do you know of any R function that performs tests like this one?

    Read the article

  • Java: I can't interact with my JFrame

    - by Wooooo
    Hi, I have a java application (1.4.2) that uses 2 JFrames. The first is Modal=true and appears on top of the second JFrame. The first JFrame allows the user to "open" a file. Once the file is ready to be displayed, the JFrame is set to setModal=false, and this.dispose() 'd of. This leaves only the second JFrame on the screen. However, I can't interact with it. The code does not throw any errors and appears to run perfectly fine. BUT I can;t interact with the second JFrame. The ONLY way to exit the JFrame is to hit the stop button on my development envirnment. I literally cannot stop the JFrame by clicking the close button, because I can't even interact with that portion of the JFrame. Any thoughts?

    Read the article

  • Javascript: gradually adding to string in each iteration ?

    - by Kim Jong Woo
    I have a string like this that is split up: var tokens = "first>second>third>last".split(">"); What I would like in each iteration is for it to return Iteration 0: "last" Iteration 1: "third>last" Iteration 2: "second>third>last" Iteration 3: "first>second>third>last" I am thinking of using decrementing index for loop.... but is there a more efficient approach ? for (int w = tokens.length-1; w == 0; w--) { }

    Read the article

  • Reportviewer - Print report - matrix report expanding horizontally to multiple pages, avoid repeating row header

    - by abc0077
    I am generating a matrix report dynamically using report viewer version 9.0 in visual studio 2010. If i export save and print then it works normally. If there more columns report expands horizontally across mutiple pages. If i give Print option available in the toolbar of the report viewer. The columns are moved to second page which is correct but the row headers (product 1, product 2) should not be repeated in the second page.In the second page report should have all details except the product information. I am also interested to know whether it is the functionality of this version report viewer.

    Read the article

  • Getting JSON data in PHP

    - by domagoj412
    I have a JSON data like this: { "hello": { "first":"firstvalue", "second":"secondvalue" }, "hello2": { "first2":"firstvalue2", "second2":"secondvalue2" } } I know how to retrieve data from object "first" (firstvalue) and second (secondvalue) but I would like to loop trough this object and as a result get values: "hello" and "hello2"... This is my PHP code: <?php $jsonData='{"hello":{"first":"firstvalue","second":"secondvalue"},""hello2":{"first2":"firstvalue2","second2":"secondvalue2"}}'; $jsonData=stripslashes($jsonData); $obj = json_decode($jsonData); echo $obj->{"hello"}->{"first"}; //result: "firstvalue" ?> Can it be done?

    Read the article

  • Loading contents of TableView Controller after showing Tab

    - by Teo
    Hello, I have a 4 tabbar application. The second tab has a tableviewController. When i select the second tab the tableview is displayed with it's contents and it works fine. The problem is that that data is comming from the network and it talks 2-3 seconds to load. So when i press the second tab it goes there after the contents have been loaded. How can i show an empty tableview (i'll put an activity indicator) and then load and show the contents? Teo

    Read the article

  • C -Segmentation fault after the 4th call of the function!

    - by FILIaS
    It seems at least weird to me... The program runs normally.But after I call the enter() function for the 4th time,there is a segmentation fault!I would appreciate any help. With the following function enter() I wanna add user commands' datas to a list. [Some part of the code is already posted on another question of me, but I think I should post it again...as it's a different problem I'm facing now.] /* struct for all the datas that user enters on file*/ typedef struct catalog { char short_name[50]; char surname[50]; signed int amount; char description[1000]; struct catalog *next; }catalog,*catalogPointer; catalogPointer current; catalogPointer head = NULL; void enter(void) //user command: i <name> <surname> <amount> <description> { int n,j=2,k=0; char temp[1500]; char *short_name,*surname,*description; signed int amount; char* params = strchr(command,' ') + 1; //strchr returns a pointer to the 1st space on the command.U want a pointer to the char right after that space. strcpy(temp, params); //params is saved as temp. char *curToken = strtok(temp," "); //strtok cuts 'temp' into strings between the spaces and saves them to 'curToken' printf("temp is:%s \n",temp); printf("\nWhat you entered for saving:\n"); for (n = 0; curToken; ++n) //until curToken ends: { if (curToken) { short_name = malloc(strlen(curToken) + 1); strncpy(short_name, curToken, sizeof (short_name)); } printf("Short Name: %s \n",short_name); curToken = strtok(NULL," "); if (curToken) { surname = malloc(strlen(curToken) + 1); strncpy(surname, curToken,sizeof (surname)); } printf("SurName: %s \n",surname); curToken = strtok(NULL," "); if (curToken) { //int * amount= malloc(sizeof (signed int *)); char *chk; amount = (int) strtol(curToken, &chk, 10); if (!isspace(*chk) && *chk != 0) fprintf(stderr,"Warning: expected integer value for amount, received %s instead\n",curToken); } printf("Amount: %d \n",amount); curToken = strtok(NULL,"\0"); if (curToken) { description = malloc(strlen(curToken) + 1); strncpy(description, curToken, sizeof (description)); } printf("Description: %s \n",description); break; } if (findEntryExists(head, surname,short_name) != NULL) //call function in order to see if entry exists already on the catalog printf("\nAn entry for <%s %s> is already in the catalog!\nNew entry not entered.\n",short_name,surname); else { printf("\nTry to entry <%s %s %d %s> in the catalog list!\n",short_name,surname,amount,description); newEntry(&head,short_name,surname,amount,description); printf("\n**Entry done!**\n"); } // Maintain the list in alphabetical order by surname. } catalogPointer findEntryExists (catalogPointer head, char num[],char first[]) { catalogPointer p = head; while (p != NULL && strcmp(p->surname, num) != 0 && strcmp(p->short_name,first) != 0) { p = p->next; } return p; } catalogPointer newEntry (catalog** headRef,char short_name[], char surname[], signed int amount, char description[]) { catalogPointer newNode = (catalogPointer)malloc(sizeof(catalog)); catalogPointer first; catalogPointer second; catalogPointer tmp; first=head; second=NULL; strcpy(newNode->short_name, short_name); strcpy(newNode->surname, surname); newNode->amount=amount; strcpy(newNode->description, description); //SEGMENTATION ON THE 4TH RUN OF PROGRAM STOPS HERE depending on the names each time it gets! while (first!=NULL) { if (strcmp(surname,first->surname)>0) second=first; else if (strcmp(surname,first->surname)==0) { if (strcmp(short_name,first->short_name)>0) second=first; } first=first->next; } if (second==NULL) { newNode->next=head; head=newNode; } else { tmp=second->next; newNode->next=tmp; first->next=newNode; } }

    Read the article

  • Haskell - Parsec Parsing <p> element

    - by Martin
    I'm using Text.ParserCombinators.Parsec and Text.XHtml to parse an input like this: This is the first paragraph example\n with two lines\n \n And this is the second paragraph\n And my output should be: <p>This is the first paragraph example\n with two lines\n</p> <p>And this is the second paragraph\n</p> I defined: line= do{ ;t<-manyTill (anyChar) newline ;return t } paragraph = do{ t<-many1 (line) ;return ( p << t ) } But it returns: <p>This is the first paragraph example\n with two lines\n\n And this is the second paragraph\n</p> What is wrong? Any ideas? Thanks!

    Read the article

  • Javascript code semantics

    - by Mohammad
    if(myVar = img.parent('a').length > 0){ var Y = 1; }else{ var Y = 2; } When I run this code myVar (being announced for the first time) takes the value of img.parent('a').length > 0 and becomes either false or true depending on the case. First Question: Is this a correct way of defining myVar? Second Question: Am I defining Y for the second time? Is my second 'var' excess? i.e. should i just write Y = 2;

    Read the article

  • Difference in techniques for setting a stubbed method's return value with Rhino Mocks

    - by CRice
    What is the main difference between these following two ways to give a method some fake implementation? I was using the second way fine in one test but in another test the behaviour can not be achieved unless I go with the first way. These are set up via: IMembershipService service = test.Stub<IMembershipService>(); so (the first), using (test.Record()) //test is MockRepository instance { service.GetUser("dummyName"); LastCall.Return(new LoginUser()); } vs (the second). service.Stub(r => r.GetUser("dummyName")).Return(new LoginUser()); Edit The problem is that the second technique returns null in the test, when I expect it to return a new LoginUser. The first technique behaves as expected by returning a new LoginUser. All other test code used in both cases is identical.

    Read the article

  • Pass Value between MDI Child in WinForm using C#

    - by abhilashca
    I have an MDI Parent, containing a MenuStrip. When I click on one of the Menu, two Child Forms are displayed simultaneoulsy. I have a TextBox and a Send Button on one of my ChildForm. When I type-in something in that TextBox and Click the Send Button, I need to show that value in the TextBox of my Second Child Form. What I had done is, I wrote a Public Function in the Second Child Form and tried to invoke it by creating an object of Second Form, on the Send Button click event. When I put break points, in that Public Function, I find that the control is flowing through that Public function on cliking the Send button. But the passed value is not displayed. And, I know that is not the standard way to do that. Any sample script for help? Thanks.

    Read the article

  • How can I get a rails server to use the same databse that cucumber uses during a test?

    - by James
    The cucumber test first makes an entry in the database and posts a form to a second server. This second server does some processing in background and then hits the first app (where the test is being run) with some data that the cucumber test needs to know about. I've tried running the main server via script/server and script/server -e test while the cucumber test is running, but I can't seem to force the server to use the same database that cucumber is using when it runs its step definitions. That is, when the second server pushes some data to a controller in the main server, the main server doesn't know about any entries that cucumber has made in the database. How can I get cucumber and the main server to use the same database?

    Read the article

  • Implementing a Custom Coherence PartitionAssignmentStrategy

    - by jpurdy
    A recent A-Team engagement required the development of a custom PartitionAssignmentStrategy (PAS). By way of background, a PAS is an implementation of a Java interface that controls how a Coherence partitioned cache service assigns partitions (primary and backup copies) across the available set of storage-enabled members. While seemingly straightforward, this is actually a very difficult problem to solve. Traditionally, Coherence used a distributed algorithm spread across the cache servers (and as of Coherence 3.7, this is still the default implementation). With the introduction of the PAS interface, the model of operation was changed so that the logic would run solely in the cache service senior member. Obviously, this makes the development of a custom PAS vastly less complex, and in practice does not introduce a significant single point of failure/bottleneck. Note that Coherence ships with a default PAS implementation but it is not used by default. Further, custom PAS implementations are uncommon (this engagement was the first custom implementation that we know of). The particular implementation mentioned above also faced challenges related to managing multiple backup copies but that won't be discussed here. There were a few challenges that arose during design and implementation: Naive algorithms had an unreasonable upper bound of computational cost. There was significant complexity associated with configurations where the member count varied significantly between physical machines. Most of the complexity of a PAS is related to rebalancing, not initial assignment (which is usually fairly simple). A custom PAS may need to solve several problems simultaneously, such as: Ensuring that each member has a similar number of primary and backup partitions (e.g. each member has the same number of primary and backup partitions) Ensuring that each member carries similar responsibility (e.g. the most heavily loaded member has no more than one partition more than the least loaded). Ensuring that each partition is on the same member as a corresponding local resource (e.g. for applications that use partitioning across message queues, to ensure that each partition is collocated with its corresponding message queue). Ensuring that a given member holds no more than a given number of partitions (e.g. no member has more than 10 partitions) Ensuring that backups are placed far enough away from the primaries (e.g. on a different physical machine or a different blade enclosure) Achieving the above goals while ensuring that partition movement is minimized. These objectives can be even more complicated when the topology of the cluster is irregular. For example, if multiple cluster members may exist on each physical machine, then clearly the possibility exists that at certain points (e.g. following a member failure), the number of members on each machine may vary, in certain cases significantly so. Consider the case where there are three physical machines, with 3, 3 and 9 members each (respectively). This introduces complexity since the backups for the 9 members on the the largest machine must be spread across the other 6 members (to ensure placement on different physical machines), preventing an even distribution. For any given problem like this, there are usually reasonable compromises available, but the key point is that objectives may conflict under extreme (but not at all unlikely) circumstances. The most obvious general purpose partition assignment algorithm (possibly the only general purpose one) is to define a scoring function for a given mapping of partitions to members, and then apply that function to each possible permutation, selecting the most optimal permutation. This would result in N! (factorial) evaluations of the scoring function. This is clearly impractical for all but the smallest values of N (e.g. a partition count in the single digits). It's difficult to prove that more efficient general purpose algorithms don't exist, but the key take away from this is that algorithms will tend to either have exorbitant worst case performance or may fail to find optimal solutions (or both) -- it is very important to be able to show that worst case performance is acceptable. This quickly leads to the conclusion that the problem must be further constrained, perhaps by limiting functionality or by using domain-specific optimizations. Unfortunately, it can be very difficult to design these more focused algorithms. In the specific case mentioned, we constrained the solution space to very small clusters (in terms of machine count) with small partition counts and supported exactly two backup copies, and accepted the fact that partition movement could potentially be significant (preferring to solve that issue through brute force). We then used the out-of-the-box PAS implementation as a fallback, delegating to it for configurations that were not supported by our algorithm. Our experience was that the PAS interface is quite usable, but there are intrinsic challenges to designing PAS implementations that should be very carefully evaluated before committing to that approach.

    Read the article

  • how to display the Grid on row click evnt on other jquery grid

    - by kumar
    Hello all, please help me out from this problem which i was facing since from long,, Comming to my applicaiton: Using Asp.net MVC with Jquery stuff, with back end DB2 I have a user controls with jquery grid in it, for the Jquery grid the URL I am assing is something like this. ID EmployeName PHoneNumber Deatils /Employee/Orders/Details /// Deails is my actionresult class.. I am getting the output result exactly what I am expecting... now I have one more action result calls LIST( List for that Deatils).. when User click on any row in the Jquery grid I need to pass ID( for that Employee to the DB2 to get that Employee List) and this Grid I need to show i nthe bottom of the first grid, Like If I click on second row I need to pass the ID to the DB2 to get second user result to display on the second grid. can anybody help me with the code.. Thanks

    Read the article

  • MySQL limit from descending order

    - by faya
    Hello, Is it available to write a query to use same "LIMIT (from), (count)", but get result in backwards? In example if I have 8 rows in the table and I want to get 5 rows in two steps I would: first step query: select * from table limit 0, 5 first step result: first 5 rows; second step query: select * from table limit 5, 5 second step result: last 3 rows; But I want to get it vice versa. I mean from the first step I want last 3 rows and from the second I want 5 first rows. Thank you for your answer

    Read the article

  • Updating Label on previously loaded view?

    - by fuzzygoat
    I am working on a simple app tab-bar based application that has two views. The first is the main application and the second is a simple instruction screen. What I am trying to do is create a update a label on that second screen as things change in the main app. Because the second screen is only simple with one label and some text I am not unloading it once its loaded. After the first viewDidLoad I can update the label just fine, but after that is there a way to catch successive view switches from the tab-bar menu so I can update the label? many thanks gary

    Read the article

  • Bash or python for changing spacing in files

    - by Werner
    Hi, I have a set of 10000 files. In all of them, the second line, looks like: AAA 3.429 3.84 so there is just one space (requirement) between AAA and the two other columns. The rest of lines on each file are completely different and correspond to 10 columns of numbers. Randomly, in around 20% of the files, and due to some errors, one gets BBB 3.429 3.84 so now there are two spaces between the first and second column. This is a big error so I need to fix it, changing from 2 to 1 space in the files where the error takes place. The first approach I thought of was to write a bash script that for each file reads the 3 values of the second line and then prints them with just one space, doing it for all the files. I wonder what do oyu think about this approach and if you could suggest something better, bashm python or someother approach. Thanks

    Read the article

< Previous Page | 224 225 226 227 228 229 230 231 232 233 234 235  | Next Page >