Search Results

Search found 12 results on 1 pages for 'pr1001'.

Page 1/1 | 1 

  • Spreading incoming batched data into a real-time stream

    - by pr1001
    I would like to display some events in 'real-time'. However, I must fetch the data from another source. I can request the last X minutes, though the source is updated approximately every 5 minutes. This means that there will be a delay between the most recent data retrieved and the point in time that I make the request. Second, because I will be receiving a batch of data, I don't want to just fire out all the events down a socket once my fetcher has retrieved it: I would like to spread out the events so that they are both accurately spaced amongst each other and in sync with their original occurrences (e.g. an event is always displayed 6 minutes after it actually happened). My thought is to fetch the data every 5 minutes from the source, knowing that I won't get the very latest data. The original data would be then queued to be sent down the socket 7.5 minutes from its original timestamp – that is, at least ~2.5 minutes from when its batch was fetched and at most 7.5 minutes since then. My question is this: is this the best way to approach the problem? Does this problem have any standard approaches or associated literature related to implementation best-practices and edge cases? I am a bit worried that the frequency of my fetches and the frequency in which the source is updated will get out of sync, leading to points where no data will be retrieved from the source. However, since my socket delay is greater than my fetch frequency, the subsequent fetch should retrieve newer data before the socket queue is empty. Is that correct? Am I missing something? Thanks!

    Read the article

  • Why do I have no TTY on a basic Ubuntu 9.10 server install?

    - by pr1001
    I have reinstalled Ubuntu 9.10 Server several times on a bog standard 1RU server and each time I finish the install and reboot I see GRUB run and am then presented with a black screen. The machine is running just fine, as I am able to SSH in, but I can't see anything on the attached monitor. I have a simple LCD screen connected via VGA and a signal is apparently being output to it, as it doesn't go asleep. Looking at /var/log/syslog I see: Mar 24 14:57:44 bridge5 rsyslogd-2039: Could no open output file '/dev/xconsole' [try http://www.rsyslog.com/e/2039 ] However, I later see: Mar 24 14:57:44 bridge5 kernel: [ 0.001368] console [tty0] enabled Any thoughts? Thanks!

    Read the article

  • Why do I have no TTY on a basic Ubuntu 9.10 server install?

    - by pr1001
    I have reinstalled Ubuntu 9.10 Server several times on a bog standard 1RU server and each time I finish the install and reboot I see GRUB run and am then presented with a black screen. The machine is running just fine, as I am able to SSH in, but I can't see anything on the attached monitor. I have a simple LCD screen connected via VGA and a signal is apparently being output to it, as it doesn't go asleep. Looking at /var/log/syslog I see: Mar 24 14:57:44 bridge5 rsyslogd-2039: Could no open output file '/dev/xconsole' [try http://www.rsyslog.com/e/2039 ] However, I later see: Mar 24 14:57:44 bridge5 kernel: [ 0.001368] console [tty0] enabled Any thoughts? Thanks!

    Read the article

  • Using Sub-Types And Return Types in Scala to Process a Generic Object Into a Specific One

    - by pr1001
    I think this is about covariance but I'm weak on the topic... I have a generic Event class used for things like database persistance, let's say like this: class Event( subject: Long, verb: String, directobject: Option[Long], indirectobject: Option[Long], timestamp: Long) { def getSubject = subject def getVerb = verb def getDirectObject = directobject def getIndirectObject = indirectobject def getTimestamp = timestamp } However, I have lots of different event verbs and I want to use pattern matching and such with these different event types, so I will create some corresponding case classes: trait EventCC case class Login(user: Long, timestamp: Long) extends EventCC case class Follow( follower: Long, followee: Long, timestamp: Long ) extends EventCC Now, the question is, how can I easily convert generic Events to the specific case classes. This is my first stab at it: def event2CC[T <: EventCC](event: Event): T = event.getVerb match { case "login" => Login(event.getSubject, event.getTimestamp) case "follow" => Follow( event.getSubject, event.getDirectObject.getOrElse(0), event.getTimestamp ) // ... } Unfortunately, this is wrong. <console>:11: error: type mismatch; found : Login required: T case "login" => Login(event.getSubject, event.getTimestamp) ^ <console>:12: error: type mismatch; found : Follow required: T case "follow" => Follow(event.getSubject, event.getDirectObject.getOrElse(0), event.getTimestamp) Could someone with greater type-fu than me explain if, 1) if what I want to do is possible (or reasonable, for that matter), and 2) if so, how to fix event2CC. Thanks!

    Read the article

  • Scala traits and implicit conversion confusion

    - by pr1001
    The following lines work when I enter them by hand on the Scala REPL (2.7.7): trait myTrait { override def toString = "something" } implicit def myTraitToString(input: myTrait): String = input.toString object myObject extends myTrait val s: String = myObject However, if I try to compile file with it I get the following error: [error] myTrait.scala:37: expected start of definition [error] implicit def myTraitToString(input: myTrait): String = input.toString [error] ^ Why? Thanks!

    Read the article

  • How can I use the Scala program schema2src?

    - by pr1001
    This perhaps more a Server Fault question... I installed schema2src via sbaz and now I would like to convert a DTD (Apple's plist schema) to Scala source. $ schema2src usage: schema2src [flags] --module mname arg* or schema2src dtd arg* or (experimental) schema2src xsd arg* (this doesn't work at all yet) where supported [flags] may be: --verbose prints some debugging information However, if I try give any argument, it appears it can't find Scala: $ schema2src --verbose Exception in thread "main" java.lang.NoClassDefFoundError: scala/runtime/BoxesUtility at schema2src.Main$.processArgs(Main.scala:56) at schema2src.Main$.main(Main.scala:25) at schema2src.Main.main(Main.scala) Caused by: java.lang.ClassNotFoundException: scala.runtime.BoxesUtility at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:315) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:330) at java.lang.ClassLoader.loadClass(ClassLoader.java:250) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:398) ... 3 more I have scala in my PATH... Any suggestions? Assuming that problem can be fixed, is this the correct syntax? $ schema2src PropertyList-1.0.dtd

    Read the article

  • How can I avoid mutable variables in Scala when using ZipInputStreams and ZipOutpuStreams?

    - by pr1001
    I'm trying to read a zip file, check that it has some required files, and then write all valid files out to another zip file. The basic introduction to java.util.zip has a lot of Java-isms and I'd love to make my code more Scala-native. Specifically, I'd like to avoid the use of vars. Here's what I have: val fos = new FileOutputStream("new.zip"); val zipOut = new ZipOutputStream(new BufferedOutputStream(fos)); while (zipIn.available == 1) { val entry = zipIn.getNextEntry if (entryIsValid(entry)) { val fos = new FileOutputStream("subdir/" + entry.getName()); val dest = new BufferedOutputStream(fos); // read data into the data Array var data: Array[Byte] = null var count = zip.read(data) while (count != -1) { dest.write(data, 0, count) count = zip.read(data) } dest.flush dest.close } }

    Read the article

  • How can I take any function as input for my Scala wrapper method?

    - by pr1001
    Let's say I want to make a little wrapper along the lines of: def wrapper(f: (Any) => Any): Any = { println("Executing now") val res = f println("Execution finished") res } wrapper { println("2") } Does this make sense? My wrapper method is obviously wrong, but I think the spirit of what I want to do is possible. Am I right in thinking so? If so, what's the solution? Thanks!

    Read the article

  • How can I get a Node adjacent to a unique Node using Scala?

    - by pr1001
    I'm trying to parse an Apple plist file and I need to get an array Node within it. Unfortunately its only unique identifier is sibling Node right before it, <key>ProvisionedDevices</key>. Right now my best thoughts are to use Java's XPATH querying or Node.indexOf. Here is an example: <plist version="1.0"> <dict> <key>ApplicationIdentifierPrefix</key> <array> <string>RP8CBF4MRE</string> </array> <key>CreationDate</key> <date>2010-05-10T11:44:35Z</date> <key>DeveloperCertificates</key> <array> ... <key>ProvisionedDevices</key> <array> ... // I need the Nodes here </array> </dict> </plist> Thanks!

    Read the article

1