Search Results

Search found 62513 results on 2501 pages for 'time series'.

Page 272/2501 | < Previous Page | 268 269 270 271 272 273 274 275 276 277 278 279  | Next Page >

  • Simple continuously running XMPP client in python

    - by tom
    I'm using python-xmpp to send jabber messages. Everything works fine except that every time I want to send messages (every 15 minutes) I need to reconnect to the jabber server, and in the meantime the sending client is offline and cannot receive messages. So I want to write a really simple, indefinitely running xmpp client, that is online the whole time and can send (and receive) messages when required. My trivial (non-working) approach: import time import xmpp class Jabber(object): def __init__(self): server = 'example.com' username = 'bot' passwd = 'password' self.client = xmpp.Client(server) self.client.connect(server=(server, 5222)) self.client.auth(username, passwd, 'bot') self.client.sendInitPresence() self.sleep() def sleep(self): self.awake = False delay = 1 while not self.awake: time.sleep(delay) def wake(self): self.awake = True def auth(self, jid): self.client.getRoster().Authorize(jid) self.sleep() def send(self, jid, msg): message = xmpp.Message(jid, msg) message.setAttr('type', 'chat') self.client.send(message) self.sleep() if __name__ == '__main__': j = Jabber() time.sleep(3) j.wake() j.send('[email protected]', 'hello world') time.sleep(30) The problem here seems to be that I cannot wake it up. My best guess is that I need some kind of concurrency. Is that true, and if so how would I best go about that? EDIT: After looking into all the options concerning concurrency, I decided to go with twisted and wokkel. If I could, I would delete this post.

    Read the article

  • How can I set the name of the class xml by constructor?

    - by spderosso
    Hi, I want to be able to do something like this: @Root(name="events") class XMLEvents { @ElementList(inline=true) ArrayList<XMLEvent> events = Lists.newArrayList(); XMLEvents(){ ... events.add(new XMLEvent(time, type, professorP)); events.add(new XMLEvent(time, type, student)); events.add(new XMLEvent(time, type, course)); ... } } The XMLEvent class to go something like: class XMLEvent { @Root(name="professor") XMLEvent(DateTime time, LogType type, Professor p){ ... } @Root(name="student") XMLEvent(DateTime time, LogType type, Student st){ ... } @Root(name="course") XMLEvent(DateTime time, LogType type, Course c){ ... } } For the output to be: <events> <professor> ... </professor> <student> ... </student> <course> ... </course> </events> So depending on the constructor I call to create a new XMLEvent the root name to which is mapped is different. Is this even possible? Of course the past example was just to transmit what I need. Putting the @Root annotation there didn't change anything Thanks!

    Read the article

  • MySQL query does not return any data

    - by Alex L
    Hi, I need to retrieve data from a specific time period. The query works fine until I specify the time period. Is there something wrong with the way I specify time period? I know there are many entries within that time-frame. This query returns empty: SELECT stop_times.stop_id, STR_TO_DATE(stop_times.arrival_time, '%H:%i:%s') as stopTime, routes.route_short_name, routes.route_long_name, trips.trip_headsign FROM trips JOIN stop_times ON trips.trip_id = stop_times.trip_id JOIN routes ON routes.route_id = trips.route_id WHERE stop_times.stop_id = 5508 HAVING stopTime BETWEEN DATE_SUB(stopTime,INTERVAL 1 MINUTE) AND DATE_ADD(stopTime,INTERVAL 20 MINUTE); Here is it's EXPLAIN: +----+-------------+------------+--------+------------------+---------+---------+-------------------------------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+--------+------------------+---------+---------+-------------------------------+------+-------------+ | 1 | SIMPLE | stop_times | ref | trip_id,stop_id | stop_id | 5 | const | 605 | Using where | | 1 | SIMPLE | trips | eq_ref | PRIMARY,route_id | PRIMARY | 4 | wmata_gtfs.stop_times.trip_id | 1 | | | 1 | SIMPLE | routes | eq_ref | PRIMARY | PRIMARY | 4 | wmata_gtfs.trips.route_id | 1 | | +----+-------------+------------+--------+------------------+---------+---------+-------------------------------+------+-------------+ 3 rows in set (0.00 sec) The query works if I remove the HAVING clause (don't specify time range). Returns: +---------+----------+------------------+-----------------+---------------+ | stop_id | stopTime | route_short_name | route_long_name | trip_headsign | +---------+----------+------------------+-----------------+---------------+ | 5508 | 06:31:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 06:57:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 07:23:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 07:49:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 08:15:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 08:41:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 09:08:00 | "80" | "" | "FORT TOTTEN" | I am using Google Transit format Data loaded into MySQL. The query is supposed to provide stop times and bus routes for a given bus stop. For a bus stop, I am trying to get: Route Name Bus Name Bus Direction (headsign) Stop time The results should be limited only to buses times from 1 min ago to 20 min from now. Please let me know if you could help.

    Read the article

  • How to index a table with a Type 2 slowly changing dimension for optimal performance

    - by The Lazy DBA
    Suppose you have a table with a Type 2 slowly-changing dimension. Let's express this table as follows, with the following columns: * [Key] * [Value1] * ... * [ValueN] * [StartDate] * [ExpiryDate] In this example, let's suppose that [StartDate] is effectively the date in which the values for a given [Key] become known to the system. So our primary key would be composed of both [StartDate] and [Key]. When a new set of values arrives for a given [Key], we assign [ExpiryDate] to some pre-defined high surrogate value such as '12/31/9999'. We then set the existing "most recent" records for that [Key] to have an [ExpiryDate] that is equal to the [StartDate] of the new value. A simple update based on a join. So if we always wanted to get the most recent records for a given [Key], we know we could create a clustered index that is: * [ExpiryDate] ASC * [Key] ASC Although the keyspace may be very wide (say, a million keys), we can minimize the number of pages between reads by initially ordering them by [ExpiryDate]. And since we know the most recent record for a given key will always have an [ExpiryDate] of '12/31/9999', we can use that to our advantage. However... what if we want to get a point-in-time snapshot of all [Key]s at a given time? Theoretically, the entirety of the keyspace isn't all being updated at the same time. Therefore for a given point-in-time, the window between [StartDate] and [ExpiryDate] is variable, so ordering by either [StartDate] or [ExpiryDate] would never yield a result in which all the records you're looking for are contiguous. Granted, you can immediately throw out all records in which the [StartDate] is greater than your defined point-in-time. In essence, in a typical RDBMS, what indexing strategy affords the best way to minimize the number of reads to retrieve the values for all keys for a given point-in-time? I realize I can at least maximize IO by partitioning the table by [Key], however this certainly isn't ideal. Alternatively, is there a different type of slowly-changing-dimension that solves this problem in a more performant manner?

    Read the article

  • Android ArrayList<Location> passing between activities

    - by squixy
    I have simple class Track, which stores information about route: import java.io.Serializable; import java.util.ArrayList; import java.util.Date; import android.location.Location; public class Track implements Serializable { private static final long serialVersionUID = -5317697499269650204L; private Date date; private String name; private int time; private double distance, speed; private ArrayList<Location> route; public Track(String name, int time, double distance, ArrayList<Location> route) { this.date = new Date(); this.name = name; this.time = time; this.distance = distance; this.speed = distance / (time / 3600.); this.route = route; } public String getDate() { return String.format("Date: %1$td-%1$tb-%1$tY%nTime: %1$tH:%1$tM:%1$tS", date); } public String getName() { return name; } public int getTime() { return time; } public double getDistance() { return distance; } public float getSpeed() { return (float) speed; } public ArrayList<Location> getRoute() { return route; } @Override public String toString() { return String.format("Name: %s%nDate: %2$td-%2$tb-%2$tY%nTime: %2$tH:%2$tM:%2$tS", name, date); } } And I'm passing it from one activity to another: Intent showTrackIntent = new Intent(TabSavedActivity.this, ShowTrackActivity.class); showTrackIntent.putExtra("track", adapter.getItem(position)); startActivity(showTrackIntent); Where (Track object is element on ListView). I get error during passing Track object: java.lang.RuntimeException: Parcelable encountered IOException writing serializable object (name = classes.Track) What is happening?

    Read the article

  • How to build a simulation of a login hardware token in .Net

    - by Michel
    Hi, i have a hardware token for remote login to some citrix environment. When i click the button on the device, i get an id and i can use that to login to the citrix farm. I can click the button as much as i like, and every time a new code gets generated, and they all work. Now i want to secure my private website likewise, but not with the hardware token, but with a 'token app' on my phone. So i run an app on my phone, generate a key, and use that to (partly) authenticate myself on the server. But here's the point: i don't know how it works! How can i generate 1, 2 or 100 keys at one time which i can see (on the server) are all valid, but without the server and the phone app having contact (the hardware token also is an 'offline' solution). Can you help me with a hint how i would do this? This is what i thought of so far: the phone app and the server app know (hardcoded) the same encryption key. The phone app encrypts the current time. The server app decrypts the string to the current time and if the diff between that time and the actual server time is less than 10 minutes it's an ok. Difficult for other users to fake a key, but encryption gives such nasty strings to enter, and the hardware token gives me nice things like 'H554TU8' And this is probably not how the real hardware token works, because the server and the phone app must 'know' the same encryption key. Michel

    Read the article

  • Why Enumerable.Range is faster than a direct yield loop?

    - by Morgan Cheng
    Below code is checking performance of three different ways to do same solution. public static void Main(string[] args) { // for loop { Stopwatch sw = Stopwatch.StartNew(); int accumulator = 0; for (int i = 1; i <= 100000000; ++i) { accumulator += i; } sw.Stop(); Console.WriteLine("time = {0}; result = {1}", sw.ElapsedMilliseconds, accumulator); } //Enumerable.Range { Stopwatch sw = Stopwatch.StartNew(); var ret = Enumerable.Range(1, 100000000).Aggregate(0, (accumulator, n) => accumulator + n); sw.Stop(); Console.WriteLine("time = {0}; result = {1}", sw.ElapsedMilliseconds, ret); } //self-made IEnumerable<int> { Stopwatch sw = Stopwatch.StartNew(); var ret = GetIntRange(1, 100000000).Aggregate(0, (accumulator, n) => accumulator + n); sw.Stop(); Console.WriteLine("time = {0}; result = {1}", sw.ElapsedMilliseconds, ret); } } private static IEnumerable<int> GetIntRange(int start, int count) { int end = start + count; for (int i = start; i < end; ++i) { yield return i; } } } The result is like this: time = 306; result = 987459712 time = 1301; result = 987459712 time = 2860; result = 987459712 It is not surprising that "for loop" is faster than the other two solutions, because Enumerable.Aggregate takes more method invocations. However, it really surprises that "Enumerable.Range" is faster than the "self-made IEnumerable". I thought that Enumerable.Range will take more overhead than the simple GetIntRange method. What is the possible reason for this?

    Read the article

  • Building static (but complicated) lookup table using templates.

    - by MarkD
    I am currently in the process of optimizing a numerical analysis code. Within the code, there is a 200x150 element lookup table (currently a static std::vector < std::vector < double ) that is constructed at the beginning of every run. The construction of the lookup table is actually quite complex- the values in the lookup table are constructed using an iterative secant method on a complicated set of equations. Currently, for a simulation, the construction of the lookup table is 20% of the run time (run times are on the order of 25 second, lookup table construction takes 5 seconds). While 5-seconds might not seem to be a lot, when running our MC simulations, where we are running 50k+ simulations, it suddenly becomes a big chunk of time. Along with some other ideas, one thing that has been floated- can we construct this lookup table using templates at compile time? The table itself never changes. Hard-coding a large array isn't a maintainable solution (the equations that go into generating the table are constantly being tweaked), but it seems that if the table can be generated at compile time, it would give us the best of both worlds (easily maintainable, no overhead during runtime). So, I propose the following (much simplified) scenario. Lets say you wanted to generate a static array (use whatever container suits you best- 2D c array, vector of vectors, etc..) at compile time. You have a function defined- double f(int row, int col); where the return value is the entry in the table, row is the lookup table row, and col is the lookup table column. Is it possible to generate this static array at compile time using templates, and how?

    Read the article

  • why do we need advanced knowledge of mathematics & physics for programming?

    - by Sumeet
    Guys, I have been very good in mathematics and physics in my schools and colleges. Right now I am a programmer. Even in the colleges I have to engrossed my self into computers and programming things all the time. As I used to like it very much. But I have always felt the lack of advanced mathematics and physics in all the work I have done (Programs). Programming never asked me any advanced mathematics and physics knowledge in what I was very good. It always ask u some optimized loops, and different programming technologies which has never been covered in advanced mathematics and physics. Even at the time of selection in big College , such a kind of advanced knowledge is required. Time by time I got out of touch of all that facts and concepts (advanced mathematics and physics). And now after, 5 years in job I found it hard to resolve Differentiations and integrations from Trigonometry. Which sometimes make me feel like I have wasted time in those concepts because they are never used. (At that time I knew that I am going to be a programmer) If one need to be a programmer why do all this advanced knowledge is required. One can go with elementry knowledge a bit more. You never got to think like scientists and R&D person in your Schols and colleges for being a programmer? Just think and let me know your thoughts. I must be wrong somewhere in what I think , but not able to figure that out..? Regards Sumeet

    Read the article

  • Check if DateTime in specific range

    - by katit
    Need to check if DateTime is in specific range. I think I need to calculate knowing YEAR first and last date of DST time in this year. How would I figure "Sunday of week 2 of March" date? From 1/1/2007 12:00:00 AM to 12/31/9999 12:00:00 AM Begins at 2:00 AM on Sunday of week 2 of March Ends at 2:00 AM on Sunday of week 1 of November For example, I need to check if 11/21/2011 is between Sunday of week 2 in March and Sunday of week 1 of November - answer should be NO If I pass 8/8/2011 - answer should be yes. Basically, I need to write function to check if my date belongs to daylight savings time. My only idea so far is to write loops to find 2nd week for example. So, I would loop from Day 1 in March until I hit Sunday second time. Same thing I would loop (increment days by 1) from day 1 of November until I hit Sunday first time. In another words, I need function to check if input data is in Daylight Savings time period. Time period defined by constraint above. P.S. I can't use TimeZoneInfo since it's in Silverlight P.P.S I can't use DateTime.IsDaylightSavingsTime as I don't have times with kind "local"

    Read the article

  • I need to make a multithreading program (python)

    - by Andreawu98
    import multiprocessing import time from itertools import product out_file = open("test.txt", 'w') P = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p','q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',] N = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] M = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'] c = int(input("Insert the number of digits you want: ")) n = int(input("If you need number press 1: ")) m = int(input("If you need upper letters press 1: ")) i = [] if n == 1: P = P + N if m == 1: P = P + M then = time.time() def worker(): for i in product(P, repeat=c): #check every possibilities k = '' for z in range(0, c): # k = k + str(i[z]) # print each possibility in a txt without parentesis or comma out_file.write( k + '\n') # out_file.close() now = time.time() diff = str(now - then) # To see how long does it take print(diff) worker() time.sleep(10) # just to check console The code check every single possibility and print it out in a test.txt file. It works but I really can't understand how can I speed it up. I saw it use 1 core out of my quad core CPU so I thought Multi-threading might work even though I don't know how. Please help me. Sorry for my English, I am from Italy.

    Read the article

  • PHP strtotime without leap-years

    - by Christian Sciberras
    With regards to this thread, I've developed a partial solution: function strtosecs($time,$now=null){ static $LEAPDIFF=86400; $time=strtotime($time,$now); return $time-((date('Y',$time)-1968)/4*$LEAPDIFF); } The function is supposed to get the number of seconds given a string without checking leap-years. It does this calculating the number of leap-years 1970 [(year-1986)/4], multiplying it by the difference in seconds between a leap-year and a normal year (which in the end, it's just the number of seconds in a day). Finally, I simply remove all those excess leap-year seconds from the calculated time. Here's some examples of the inputs/outputs: // test code echo strtosecs('+20 years',0).'=>'.(strtosecs('+20 years',0)/31536000); echo strtosecs('+1 years',0).'=>'.(strtosecs('+1 years',0)/31536000); // test output 630676800 => 19.998630136986 31471200 => 0.99794520547945 You will probably ask why am I doing a division on the output? It's to test it out; 31536000 is the number of seconds in a year, so that 19.99... should be 20 and 0.99... should be a 1. Sure, I could round it all and get "correct" answer, but I'm worried about the inaccuracies.

    Read the article

  • Asynchronous URL connection objective C

    - by tweety
    I created an asynchronous URL connection to call a web service using HTTP POST method. after I am pinging the web i set an NSTimerInterval in the completion handler. my problem is when I'm trying to display the time on the view controller it is not doing promptly. I know block is stored in the heap and gets executed later on anytime and probably that's why i'm not getting prompt answer. I was wondering is there any other way to do this? Thanks in advance. my code: __block NSDate *start= [NSDate date]; __block NSDate *end; __block double miliseconds; __block NSTimeInterval time; [NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) { if([data length]==0 && error==nil){ end=[NSDate date]; time=[end timeIntervalSinceDate:start]; NSLog(@"Successfully Pinged"); miliseconds = time; // calling a method to display ping time [self label:miliseconds]; } -(void) label:(double) mili{ double miliseconds=mili*1000; self.timeDisplay.text=[NSString stringWithFormat:@"Time: %.3f ms", miliseconds];

    Read the article

  • Matlab fft function

    - by CTZStef
    The code below is from the Matlab 2011a help about fft function. I think there is a problem here : why do they multiply t(1:50) by Fs, and then say it's time in millisecond ? Certainly, it happens to be true in this very particular case, but change the value of Fs to, say, 2000, and it won't work anymore, obviously because of this factor of 2. Right ? Quite misleading, isn't it ? What do I miss ? Fs = 1000; % Sampling frequency T = 1/Fs; % Sample time L = 1000; % Length of signal t = (0:L-1)*T; % Time vector % Sum of a 50 Hz sinusoid and a 120 Hz sinusoid x = 0.7*sin(2*pi*50*t) + sin(2*pi*120*t); y = x + 2*randn(size(t)); % Sinusoids plus noise plot(Fs*t(1:50),y(1:50)) title('Signal Corrupted with Zero-Mean Random Noise') xlabel('time (milliseconds)') Clearer with this : fs = 2000; % Sampling frequency T = 1 / fs; % Sample time L = 1000; % Length of signal t2 = (0:L-1)*T; % Time vector f = 50; % signal frequency s2 = sin(2*pi*f*t2); figure, plot(fs*t2(1:50),s2(1:50)); % NOT good figure, plot(t2(1:50),s2(1:50)); % good

    Read the article

  • Convincing why testing is good

    - by FireAphis
    Hello, In my team of real-time-embedded C/C++ developers, most people don't have any culture of testing their code beyond the casual manual sanity checks. I personally strongly believe in advantages of autonomous automatic tests, but when I try to convince I get some reappearing arguments like: We will spend more time on writing the tests than writing the code. It takes a lot of effort to maintain the tests. Our code is spaghetti; no way we can unit-test it. Our requirement are not sealed – we’ll have to rewrite all the tests every time the requirements are changed. Now, I'd gladly hear any convincing tips and advises, but what I am really looking for are references to researches, articles, books or serious surveys that show (preferably in numbers) how testing is worth the effort. Something like "We in IBM/Microsoft/Google, surveying 3475 active projects, found out that putting 50% more development time into testing decreased by 75% the time spent on fixing bugs" or "after half a year, the time needed to write code with test was only marginally longer than what used to take without tests". Any ideas? P.S.: I'm adding C++ tag too in case someone has a specific experience with convincing this, usually elitist, type of developers :-)

    Read the article

  • Esper generating episodes

    - by Jasonojh
    I would like to use Esper to generate episodes of events. I am trying to detect the changes in robot movement during each time period and was wondering what would be the best way of implementation. The rules for generation of episodes from the events would be If the new event time(eg. 7sec, robot A) of a robot is more than 3 sec than the latest event(eg. 3 sec, robot A) of the same robot, the new event belongs to a new episode. Each episode should represent only one robot (eg. 2sec, robotA and 3sec, robotB should output 2 episodes) Input data: Event Time Robot Position 1 1 A 0 2 2 A 1 3 6 A 2 Output data should be: Array[0]={Event 1,Event 2} Array[1]={Event 3} //more than 3 sec Input data: Event Time Robot Position 1 1 A 0 2 2 A 1 3 4 B 0 4 6 A 2 Output data should be: Array[0]={Event 1,Event 2} Array[1]={Event 3} //different robot Array[2]={Event 4} Please help provide suggestions. I have tried using mulitple listeners, one for each robot, to create episodes and it works but I am trying to use a single EPL statement to do it. I have tried win:time_accum(3sec) group by robot but the second example output: Array[0]={Event 1,Event 2, Event 4} Array[1]={Event 3} as the time window is shifted everytime an event comes in, the system still thinks that event 4 is less than 3 sec due to event 3. how do I create a unique time window for each robot? Thank you for your suggestions and any help is greatly appreciated.

    Read the article

  • How to display buttons after enterframe event is over in Corona?

    - by user1463542
    I am trying to display two buttons called countd_again and main_menu after my enterframe event is over. I can't see those buttons after enterframe event is over,though. Can you check my code,please? And also i want to add new addListener for the buttons using director and scene. module(..., package.seeall) function new() local localGroup = display.newGroup(); display.setStatusBar(display.HiddenStatusBar) local background = display.newImage("background.png") start=os.time() cnt=1 local countd_again = display.newImage("yeniden.png") countd_again.x=100 countd_again.y=100 countd_again.isVisible= false; countd_again.alpha=0; countd_again.scene="helloWorld"; local main_menu= display.newImage("anamenu.png") main_menu.x=100 main_menu.y=300 main_menu.isVisible=false; main_menu.alpha=0; main_menu.scene="helloWorld" -- listener function local function onEveryFrame( event ) if (cnt~=0) then cnt= 3-(os.time()-start) minute = math.floor(cnt/60) second=cnt%60 --print(minute,second) minTxt=display.newText(minute,50,50,nil,100) secTxt=display.newText(second,250,50,nil,100) transition.to(minTxt, {time=100, alpha=0}) transition.to(secTxt,{time=100, alpha=0}) else Runtime: removeEventListener("enterFrame",onEveryFrame) countd_again.isVisible=true; main_menu.isVisible=true; transition.to(countd_again,{time=500,alpha=1}); transition.to(main_menu,{time=500,alpha=1}); countd_again: addEventListener("touch", changeScene) main_menu: addEventListener("touch", changeScene) end end -- assign the above function as an "enterFrame" listener Runtime:addEventListener( "enterFrame", onEveryFrame ) function changeScene(e) if(e.phase=="ended") then director:changeScene(e.target.scene); end end countd_again: addEventListener("touch", changeScene) main_menu: addEventListener("touch", changeScene) localGroup: insert(countd_again) localGroup:insert(main_menu) localGroup:insert(background) return localGroup; end

    Read the article

  • Stop SQL returning the same result twice in a JOIN

    - by nbs189
    I have joined together several tables to get data i want but since I am new to SQL i can't figure out how to stop data being returned more than once. her's the SQL statement; SELECT T.url, T.ID, S.status, S.ID, E.action, E.ID, E.timestamp FROM tracks T, status S, events E WHERE S.ID AND T.ID = E.ID ORDER BY E.timestamp DESC The data that is returned is something like this; +----------------------------------------------------------------+ | URL | ID | Status | ID | action | ID | timestamp | +----------------------------------------------------------------+ | T.1 | 4 | hello | 4 | has uploaded a track | 4 | time | | T.2 | 3 | bye | 3 | has some news | 3 | time | | t.1 | 4 | more | 4 | has some news | 4 | time | +----------------------------------------------------------------+ That's a very basic example but does outline what happens. If you look at the third row the URL is repeated when there is a different status. This is what I want to happen; +-------------------------------------------------------+ | URL or Status | ID | action | timestamp | +-------------------------------------------------------+ | T.1 | 4 | has uploaded a track | time | | hello | 3 | has some news | time | | bye | 4 | has some news | time | +-------------------------------------------------------+ Please notice that the the url (in this case the mock one is T.1) is shown when the action is has uploaded a track. This is very important. The action in the events table is inserted on trigger of a status or track insert. If a new track is inserted the action is 'has uploaded a track' and you guess what it is for a status. The ID and timestamp is also inserted into the events table at this point. Note: There are more tables that go into the query, 3 more in fact, but I have left them out for simplicity.

    Read the article

  • How to effectively execute this cron job?

    - by Lost_in_code
    I have a table with 200 rows. I'm running a cron job every 10 minutes to perform some kind of insert/update operation on the table. The operation needs to be performed only on 5 rows at a time every time the cron job runs. So in first 10 mins records 1-5 are updated, records 5-10 in the 20th minute and so on. When the cron job runs for the 20th time, all the records in the table would have been updated exactly once. This is what is to be achieved at least. And the next cron job should repeat the process again. The problem: is that, every time a cron job runs, the insert/update operation should be performed on N rows (not just 5 rows). So, if N is 100, all records would've been updated by just 2 cron jobs. And the next cron job would repeat the process again. Here's an example: This is the table I currently have (200 records). Every time a cron job executes, it needs to pick N records (which I set as a variable in PHP) and update the time_md5 field with the current time's MD5 value. +---------+-------------------------------------+ | id | time_md5 | +---------+-------------------------------------+ | 10 | 971324428e62dd6832a2778582559977 | | 72 | 1bd58291594543a8cc239d99843a846c | | 3 | 9300278bc5f114a290f6ed917ee93736 | | 40 | 915bf1c5a1f13404add6612ec452e644 | | 599 | 799671e31d5350ff405c8016a38c74eb | | 56 | 56302bb119f1d03db3c9093caf98c735 | | 798 | 47889aa559636b5512436776afd6ba56 | | 8 | 85fdc72d3b51f0b8b356eceac710df14 | | .. | ....... | | .. | ....... | | .. | ....... | | .. | ....... | | 340 | 9217eab5adcc47b365b2e00bbdcc011a | <-- 200th record +---------+-------------------------------------+ So, the first record(id 10) should not be updated more than once, till all 200 records are updated once - the process should start over once all the records are updated once. I have some idea on how this could be achieved, but I'm sure there are more efficient ways of doing it. Any suggestions?

    Read the article

  • Python : How do you find the CPU consumption for a piece of code?

    - by Yugal Jindle
    Background: I have a django application, it works and responds pretty well on low load, but on high load like 100 users/sec, it consumes 100% CPU and then due to lack of CPU slows down. Problem : Profiling the application gives me time taken by functions. This time increases on high load. Time consumed may be due to complex calculation or for waiting for CPU. so, how to find the CPU cycles consumed by a piece of code ? Since, reducing the CPU consumption will increase the response time. I might have written extremely efficient code and need to add more CPU power OR I might have some stupid code taking the CPU and causing the slow down ? Any help is appreciated ! Update: I am using Jmeter to profile my webapp, it gives me a throughput of 2 requests/sec. [ 100 users] I get a average time of 36 seconds on 100 request vs 1.25 sec time on 1 request. More Info Configuration Nginx + Uwsgi with 4 workers No database used, using a responses from a REST API On 1st hit the response of REST API gets cached, therefore doesn't makes a difference. Using ujson for json parsing. Curious to Know: Python-Django is used by so many orgs for so many big sites, then there must be some high end Debug / Memory-CPU analysis tools. All those I found were casual snippets of code that perform profiling.

    Read the article

  • A basic load test question

    - by user236131
    I have a very basic load test question. I am running a load test using VSTS 2008 and I have test rig with controller + 10 agents. This load test is against a SharePoint farm I have. My goal of the load test is to find out the resource utilization on web+app+db tiers of my farm for any given load scenario. An example of a load scenario is Usage profile: Average collaboration (as defined by SCCP) User Load: 500 (using step load pattern=a step of 50 every 2 mins and a warm up time of 2mins for every step) Think time: 0 Load duration: 8hrs Now, the question is: Is it fair to expect that metrics like Requests/sec, %processor time on web front end / App / DB, Test/sec, and etc become flat or enter a steady state at one point in time during the load test. Like I said, the goal is not to create a bottleneck but to only measure the utilization of resources by the above load profile. I am asking this question because I see something different. At one point in the load test, requests/sec becomes more or less flat. But processor utilization on the web/DB servers keeps increasing. After digging through the data a bit, I see that "tests running" counter also steadily increased over time. So, if I run the load test for more than 8hrs, %processor may go up further. This way, I don't know what to consider as the load excreted by the load profile. What does this "tests running" counter really signify? How is this different from tests/sec? Another question is: how can I find out why "tests running" counter shows an increase overtime? Thanks for your time

    Read the article

  • In sync query calls, one query causing other query to run slower. Why?

    - by Irchi
    Sorry for the long question, but I think this is an interesting situation and I couldn't find any explanations for it: I was involved in optimization of an application that performed a large number of sequential SELECT and INSERT statements on a single dedicated SQL Server database. The process needs to INSERT a large number of records into a table, but for each of them there should be some value mappings, which performed using SELECT statements on another table in the same database. For a specific execution, it took 90 minutes to run. I used a profiler (JProfiler - the application is Java-based) to determine how much time does each part of the application take. It yields that 60% of the time was spent on INSERT method calls, and almost 20% on SELECT calls (the rest distributed in other parts). After some trials, I came to this situation: I commented out the INSERT query that took 60% of the time. I was expecting for the total run time to be around 35 minutes, as I have removed 60% of the 90 minutes. But the whole process took the same 90 minutes (doing only SELECTs and nothing else), but each SELECT took longer this time! Everything was running sync, there were no async calls. And there was only one single thread of execution. SELECT and INSERT queries are very simple, and don't have anything special, and they are on different tables, but on the same DB. I tested with both the DB on the application machine, and on a remote network machine. I can't think of any explanation for this, as the Profiler (Application profiler, not SQL Profiler) reported the changes in the method call times, and by removing INSERT statements SELECT statements took longer to run. Can anyone give me some kind of explanation of what could have happened? (there can't be cache / query optimization stuff, because the queries were run in sync, and in a single thread, and it was far from affecting the cache this much) I should note that the bottleneck of the speed was in SQL server, using most of the CPU time.

    Read the article

  • Multiple JOIN and SELECT Statements from eight tables

    - by user1486004
    I am trying to make an SQL statement that takes eight different numbers and searches eight different tables from one database for the corresponding value. I keep getting invalid syntax, but I can't figure out why. Here is my code: SELECT cable_length.ID, drawing.ID, optional.ID, output_type.ID, pressure_range.ID, pressure_type.ID, series.ID, termination.ID FROM ( SELECT value AS cable_length FROM A1 WHERE A1.id = %s JOIN SELECT value AS drawing FROM A2 WHERE A2.id = %s, JOIN SELECT value AS optional FROM A3 WHERE A3.id = %s, JOIN SELECT value AS output_type FROM A4 WHERE A4.id = %s, JOIN SELECT value AS pressure_range FROM A5 WHERE A5.id = %s, JOIN SELECT value AS pressure_type FROM A6 WHERE A6.id = %s, JOIN SELECT value AS series FROM A7 WHERE A7.id = %s, JOIN SELECT value AS termination FROM A8 WHERE A8.id = %s ); The %s will be changed to numbers only. The column name in each database is "ID" and "Value". I want to search by "ID" and return "Value". Any help is greatly appreciated.

    Read the article

  • Silverlight 4 toolkit, charting and lineSeries is null

    - by Snake
    Hi, I create a Silverlight Chart, with the Silverlight 4 toolkit, the April release. Consider the following chart: <Grid x:Name="LayoutRoot" Background="White"> <Charting:Chart Title="Chart to test" Name="MySuperChart"> <Charting:LineSeries x:Name="MyLineSeries" Title="Something" /> </Charting:Chart> </Grid> So far so good. I can access the Series in the chart by MySuperChart.Series[0] But when I try to reference MyLineSeries, it appears to be null. Full view

    Read the article

  • Can I override task :environment in test_helper.rb to test rake tasks?

    - by Michael Barton
    I have a series of rake tasks in a Rakefile which I'd like to test as part of my specs etc. Each task is defined in the form: task :do_somthing => :environment do # Do something with the database here end Where the :environment task sets up an ActiveRecord/DataMapper database connection and classes. I'm not using this as part of Rails but I have a series of tests which I like to run as part of BDD. This snippet illustrates how I'm trying to test the rake tasks. def setup @rake = Rake::Application.new Rake.application = @rake load File.dirname(__FILE__) + '/../../tasks/do_something.rake' end should "import data" do @rake["do_something"].invoke assert something_in_the_database end So my request for help - is it possible to over-ride the :environment task in my test_helper.rb file so I my rake testing interacts with the my test database, rather than production? I've tried redefining the task in the helper file, but this doesn't work. Any help for a solution would be great, as I've been stuck on this for the past week.

    Read the article

< Previous Page | 268 269 270 271 272 273 274 275 276 277 278 279  | Next Page >