Stephen Connolly stephenc

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The costs of guarding logging with Apache Log4J version 2

Another interesting tidbit:

@Benchmark
public void debug1Arg_date(Blackhole blackhole) {
    LOGGER.debug("Started at %s", new Date(time));
    time++;
    blackhole.consume(time);
}

@Benchmark
public void guardedDebug1Arg_date(Blackhole blackhole) {
    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("Started at %s", new Date(time));
    }
    time++;
    blackhole.consume(time);
}

Gives the following benchmark results:

Benchmark                            Mode  Cnt          Score         Error  Units
Log4jBenchmark.debug1Arg_date         thrpt   20  179653191.248 ± 2731044.349  ops/s
Log4jBenchmark.guardedDebug1Arg_date  thrpt   20  207001790.376 ± 2074020.617  ops/s

We can also compare guarding with SLF4J over logback

Java Created Mon, 05 Dec 2016 00:00:00 +0000

The costs of Java Utils Logging
One of my colleagues had a question:
Now for some context, when the Jenkins project started off, Kohsuke was working for Sun and felt it would be wrong, as a Sun employee, to use a logging framework other than that provided by the JVM as using a different logging framework could be seen as being implication that the built in Java Utils Logging framework was a steaming pile of excrement.
Java Created Mon, 05 Dec 2016 00:00:00 +0000

The costs of other logging frameworks

You asked for it.

Logback:

@Benchmark
public void debug1Arg_date(Blackhole blackhole) {
    LOGGER.debug("Started at {}", new Date(time));
    time++;
    blackhole.consume(time);
}
@Benchmark
public void debug2Arg_date(Blackhole blackhole) {

    LOGGER.debug("Started at {}", new Date(time), null);
    time++;
    blackhole.consume(time);
}
@Benchmark
public void debugNArg_date(Blackhole blackhole) {
    LOGGER.debug("Started at {}", new Date(time), null, null);
    time++;
    blackhole.consume(time);
}
static {

    ch.qos.logback.classic.Logger root = (ch.qos.logback.classic.Logger)LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME);
    root.setLevel(ch.qos.logback.classic.Level.INFO);
}

And the benchmarks

Benchmark                     Mode  Cnt          Score         Error  Units 
LogbackBenchmark.debug1Arg_date  thrpt   20  221056534.656 ± 8549233.826  ops/s
LogbackBenchmark.debug2Arg_date  thrpt   20  220576341.742 ± 3778270.898  ops/s
LogbackBenchmark.debugNArg_date  thrpt   20  134887126.088 ± 2973182.812  ops/s

JUL over SLF4J (same benchmark code but different dependency)

Java Created Mon, 05 Dec 2016 00:00:00 +0000

Log4j 2.0 Async loggers and immutability
One of the headline grabbing things that people seem to be raving about over Log4J 2.0 is async loggers.
Now do not get me wrong, they are great… as long as you know what you are doing.
If you are using async loggers you had better make sure you are only passing immutable objects to your loggers, because otherwise you may end up logging the state of your objects at the time of the log record being written and not the time you called log.
Java Created Mon, 28 Jul 2014 00:00:00 +0000

OpenEjb, Jetty and Maven - Transaction Management

I’ve been meaning to blog about getting transaction management working with OpenEjb and Jetty using jetty:run… it’s still an on-going story… but the following might get you going…

First off, in your pom.xml you need to add the configuration for maven-jetty-plugin… we need to dance around the various activemq/activeio versions and ensure that we get the correct version of ant…

<?xml version="1.0"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" 
	    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.apache.openejb.examples</groupId>
  <artifactId>jetty-openejb</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>jetty-openejb Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <build>
    <finalName>${project.artifactId}</finalName>
    <plugins>
      <plugin>
        <groupId>org.mortbay.jetty</groupId>
        <artifactId>maven-jetty-plugin</artifactId>
        <version>6.1.22</version>
        <dependencies>
          <dependency>
            <groupId>org.apache.activemq</groupId>
            <artifactId>activemq-core</artifactId>
            <version>4.1.1</version>
            <exclusions>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
              </exclusion>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging-api</artifactId>
              </exclusion>
              <exclusion>
                <groupId>org.apache.activemq</groupId>
                <artifactId>activeio-core</artifactId>
              </exclusion>
            </exclusions>
          </dependency>
          <dependency>
            <groupId>org.apache.activemq</groupId>
            <artifactId>activemq-ra</artifactId>
            <version>4.1.1</version>
            <exclusions>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
              </exclusion>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging-api</artifactId>
              </exclusion>
              <exclusion>
                <groupId>org.apache.activemq</groupId>
                <artifactId>activeio-core</artifactId>
              </exclusion>
            </exclusions>
          </dependency>
          <dependency>
            <groupId>org.apache.activemq</groupId>
            <artifactId>activeio-core</artifactId>
            <version>3.1.2</version>
            <exclusions>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
              </exclusion>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging-api</artifactId>
              </exclusion>
            </exclusions>
          </dependency>
          <dependency>
            <groupId>org.apache.openejb</groupId>
            <artifactId>openejb-core</artifactId>
            <version>3.1.2</version>
            <exclusions>
              <exclusion>
                <groupId>org.apache.activemq</groupId>
                <artifactId>activemq-core</artifactId>
              </exclusion>
              <exclusion>
                <groupId>org.apache.activemq</groupId>
                <artifactId>activemq-ra</artifactId>
              </exclusion>
              <exclusion>
                <groupId>org.apache.activemq</groupId>
                <artifactId>activeio-core</artifactId>
              </exclusion>
              <exclusion>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
              </exclusion>
            </exclusions>
          </dependency>
          <!-- in order to use the latest version of openejb, we need to exclude
               the dependencies provided in jsp-2.1-jetty -->
          <dependency>
            <groupId>org.mortbay.jetty</groupId>
            <artifactId>jsp-2.1-jetty</artifactId>
            <version>6.1.22</version>
            <exclusions>
              <exclusion>
                <groupId>ant</groupId>
                <artifactId>ant</artifactId>
              </exclusion>
            </exclusions>
          </dependency>
        </dependencies>
        <configuration>
          <jettyConfig>${basedir}/src/main/jetty/jetty.xml</jettyConfig>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

Next we need to configure a src/main/jetty/jetty.xml to bind the UserTransaction instance into jetty…

Java Maven JavaEE Created Wed, 10 Mar 2010 00:00:00 +0000

Acer Aspire One, Huawei E169G and Three IR
One of my co-workers has asked me to post this up. It’s rough and ready, so make of it what you want.
First off, Acer recently pushed an update for better performance with the Huawei USB modems… I’m assuming that you have this update… check if the file /etc/udev/rules.d/10-Huawei-Datacard.rules exists.
If that file exists then when you plug in a E169g it will be correctly autodetected without requiring poking about with usbmodeswitch… it will bind the three serial ports of the E169G to /dev/HuaweiMobile-0, /dev/HuaweiMobile-1 and /dev/HuaweiMobile-2.
Java JavaEE Created Tue, 21 Oct 2008 00:00:00 +0000
JPA, equals() and hashCode()
http://burtbeckwith.com/blog/?p=53
Java JavaEE Created Fri, 14 Dec 2007 00:00:00 +0000
Combining Hibernate and Facelets with Maven, Netbeans and Glassfish
Note to self, for later reading
http://technology.amis.nl/blog/?p=2610
Not sure why netbeans is essential on this!
Java Maven JavaEE Created Wed, 21 Nov 2007 00:00:00 +0000
JAX-WS 2.1 madness
I am sick of the fun that is getting JAX-WS 2.1 to work on JVM 1.6.
Oh, copy these four jars into the endorsed directory and then you can use JAX-WS 2.1… oh but sometimes it won’t work for some unknown reason and then it will work again.
How you are supposed to explain this to end users, I don’t know.
So next you need a platform specific installer to put those jars into the correct location, or a platform specific start script to tell the JVM about my alternate endorsed lib folder… or do I write a self-extracting jar file that exctracts the libs and forks a second JVM… no that won’t work for people wanting to use my library..
Java JavaEE Created Wed, 05 Sep 2007 00:00:00 +0000
JPA Entity exerciser
Working on this to add to EasyGloss.
There are a number of rules that JPA entities must obey:
- equals and hashCode must only be based on the persistent fields that are @Id annotated.
- annotations must be applied to either fields or getters, no mix & match (although future versions of the spec may provide for such)
- In general, getters and setters should be simple methods (i.e. no complex processing)
I want to have a JPA Entity excerciser that will check these rules for you (and can be included in your unit tests)
Java JavaEE Created Fri, 20 Jul 2007 00:00:00 +0000

Stephen Connolly stephenc

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