2. Maijs 2014

• par "wow" tehnoloģijām
• 2014.05.02, 10:46
• kādu laiku nav nekas tāda īsta "wow" vērts redzēts.
  
  "wow" - tas ir tehnoloģija, kas izmaina visu. piemēram, pirmais "wow" bija pieslēgums internetam (tīklam). vai terminālis skolā, vai modems un bbs (pēc tam - iezvanpieeja) mājās. IRC, MUD, ftp.
  "wow" bija pirmā 3d spēle (Wolfenstein), pirmais deathmatch (Doom), pirmā īstā 3rd spēle (Quake, ar specializētu 3d karti - 3dfx).
  "wow" bija strādājošs touchscreen (iPhone, tad iPad). mazāks, bet wow ir retina displeji (3K, 4K izšķirtspēja).
  
  prognozēju, ka nākamais "wow" lēciens būs 1) VR - virtuālā realitāte (Occulus, etc), 2) AR - augmented reality (Google glass, ko tur Valve dara).
  Pēc pirmā VR, parādīsies nākamais, tad aiznākamais, līdz panāks "īstu" virtuālo realitāti.
  AR varētu būt revolūcija drošības ziņā (life recording), jo visam kas notiek, būs perfekta liecība. (Līdzīgi kā ar auto fullhd dashcam).
  
  Interesanti būs ar self-driving automašīnu, kombinācijā ar elektro-auto, ja izgudros sakarīgus akumulatorus.
  
• 11 rakstair doma

• 2014.05.02, 17:59
• I was fighting a really nasty persistent issue that Tomcat would fail to start if launched from Ant script like so (part of complicated ant script that fills out placeholders conditionally and so on, executed by Jenkins):
  

  <java jar="${tomcat.home}/bin/bootstrap.jar" fork="true" clonevm="true">
  
      <jvmarg value="-XX:+UseParallelOldGC"/>
      <jvmarg value="-verbose:gc"/>
      <jvmarg value="-XX:+PrintGCTimeStamps"/>
      <jvmarg value="-XX:+PrintGCDetails"/>
      <jvmarg value="-Xloggc:${tomcat.base}/logs/gcLog_${jvmRoute}.log"/>
  ...
      <jvmarg value="-Djava.util.logging.config.file=${tomcat.base}/conf/logging.properties"/>
      <jvmarg value="-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager"/>
      <jvmarg value="-Dcom.sun.management.jmxremote=true"/>
      <jvmarg value="-Dcom.sun.management.jmxremote.port=${port.jmx}"/>
      <jvmarg value="-Dcom.sun.management.jmxremote.authenticate=false"/>
      <jvmarg value="-Dcom.sun.management.jmxremote.ssl=false"/>
      <jvmarg value="${solrProperty}"/>
      <jvmarg line="${JAVA_OPTS}"/>
      <jvmarg line="${jacocoArgLine}"/>
      <env key="APP_CONFIG_ROOT" path="${APP_CONFIG_ROOT}"/>
  </java>
  

  
  
  The symptom is that it fails with following error:
  

  Could not load Logmanager "org.apache.juli.ClassLoaderLogManager"
  java.lang.ClassNotFoundException: org.apache.juli.ClassLoaderLogManager
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [...]
  	at java.util.logging.LogManager.(LogManager.java:173)
  	at java.util.logging.Logger.demandLogger(Logger.java:336)
  	at java.util.logging.Logger.getLogger(Logger.java:390)
  	at com.sun.jmx.remote.util.ClassLogger.(ClassLogger.java:55)
  	at sun.management.jmxremote.ConnectorBootstrap.(ConnectorBootstrap.java:823)
  	at sun.management.Agent.startAgent(Agent.java:260)
  	at sun.management.Agent.startAgent(Agent.java:456)
  Can't load log handler "1catalina.org.apache.juli.FileHandler"
  java.lang.ClassNotFoundException: 1catalina.org.apache.juli.FileHandler
  java.lang.ClassNotFoundException: 1catalina.org.apache.juli.FileHandler
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [...]
  	at sun.management.Agent.startAgent(Agent.java:260)
  	at sun.management.Agent.startAgent(Agent.java:456)
  Can't load log handler "1catalina.org.apache.juli.FileHandler"
  java.lang.ClassNotFoundException: 1catalina.org.apache.juli.FileHandler
  java.lang.ClassNotFoundException: 1catalina.org.apache.juli.FileHandler
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  [...]
  	at sun.management.Agent.startAgent(Agent.java:456)
  Can't load log handler "2localhost.org.apache.juli.FileHandler"
  java.lang.ClassNotFoundException: 2localhost.org.apache.juli.FileHandler
  java.lang.ClassNotFoundException: 2localhost.org.apache.juli.FileHandler
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [...]
  	at sun.management.Agent.startAgent(Agent.java:456)
  Can't load log handler "3manager.org.apache.juli.FileHandler"
  java.lang.ClassNotFoundException: 3manager.org.apache.juli.FileHandler
  java.lang.ClassNotFoundException: 3manager.org.apache.juli.FileHandler
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [...]
  	at sun.management.Agent.startAgent(Agent.java:456)
  Can't load log handler "4host-manager.org.apache.juli.FileHandler"
  java.lang.ClassNotFoundException: 4host-manager.org.apache.juli.FileHandler
  java.lang.ClassNotFoundException: 4host-manager.org.apache.juli.FileHandler
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  [...]
  	at sun.management.Agent.startAgent(Agent.java:456)
  Error: Could not find or load main class 
  

  
  
  It turns out, the error is really simple.
  If placeholders for <jvmarg value="${solrProperty}"/>, <jvmarg line="${JAVA_OPTS}"/>, <jvmarg line="${jacocoArgLine}"/> are somehow empty, then Tomcat will crash and burn.
  Furthermore, they can't be empty strings. And they can't be standalone strings. You can put some nonsense like "-Dpunk=nown" in place of those, and Tomcat starts happily up.
  Make sure all placeholders are filled out.
  
  upd: The empty arg of <jvmarg value="${solrProperty}"/> is the real culprit. It should be jvmarg line=... .
  Tags: java
  
  
• 0 rakstair doma