Days of ... (technology)

SOLVED: VIM in terminal not rendering backround color properly

Fri, 19 Apr 2013 02:37:23 GMT

TL;DR


if &term =~ '256color'
  set t_ut=
endif

SOLVED: Coherence 3.6 problem starting two nodes on the same machine

Thu, 10 May 2012 12:39:06 GMT

I am trying to configure Weblogic 10.3.5 with Coherence cluster and two nodes. Everything is running on my local machine. I configured Coherence with WLST and now trying to run both nodes. One node starts and second fails with following exception:

2012-05-10 12:57:37.681/6.175 Oracle Coherence GE 3.6.0.4 (thread=Environment.Background.Executor:Thread-1, member=n/a): Error while starting cluster: java.lang.NullPointerException at com.tangosol.coherence.component.net.TcpRing.ensureSelector(TcpRing.CDB:7) at com.tangosol.coherence.component.net.TcpRing.setServerSocketChannel(TcpRing.CDB:20) at com.tangosol.coherence.component.net.Cluster.onStart(Cluster.CDB:510) at com.tangosol.coherence.component.net.Cluster.start(Cluster.CDB:11) at com.tangosol.coherence.component.util.SafeCluster.startCluster(SafeCluster.CDB:3) at com.tangosol.coherence.component.util.SafeCluster.restartCluster(SafeCluster.CDB:7) at com.tangosol.coherence.component.util.SafeCluster.ensureRunningCluster(SafeCluster.CDB:26) at com.tangosol.coherence.component.util.SafeCluster.start(SafeCluster.CDB:2) at com.tangosol.net.CacheFactory.ensureCluster(CacheFactory.java:998) at com.tangosol.net.DefaultConfigurableCacheFactory.ensureServiceInternal(DefaultConfigurableCacheFactory.java:923) at com.tangosol.net.DefaultConfigurableCacheFactory.ensureService(DefaultConfigurableCacheFactory.java:892) at com.oracle.coherence.environment.extensible.ExtensibleEnvironment.ensureService(ExtensibleEnvironment.java:497) at com.tangosol.net.DefaultConfigurableCacheFactory.ensureCache(DefaultConfigurableCacheFactory.java:874) at com.tangosol.net.DefaultConfigurableCacheFactory.configureCache(DefaultConfigurableCacheFactory.java:1231) at com.tangosol.net.DefaultConfigurableCacheFactory.ensureCache(DefaultConfigurableCacheFactory.java:290) at com.oracle.coherence.common.util.ObjectProxyFactory.ensureCache(ObjectProxyFactory.java:285) at com.oracle.coherence.common.util.ObjectProxyFactory.onDependenciesSatisfied(ObjectProxyFactory.java:307) at com.oracle.coherence.environment.extensible.dependencies.DependencyTracker.processLater(DependencyTracker.java:204) at com.oracle.coherence.environment.extensible.dependencies.DependencyTracker.processLater(DependencyTracker.java:46) at com.oracle.coherence.common.events.processing.AbstractAsynchronousEventProcessor$1.run(AbstractAsynchronousEventProcessor.java:53) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:619)

I configured servers to run on the same port and enabled Unicast Port Auto Adjust, thinking that Coherence would be smart enough to figure out that port is in use.

But it is not that smart!

But Oracle Metalink has more information about it:

Cause

Coherence 3.6 has since Patch 2 been enhancing its network throughput by using two open UDP ports for each member. For this Coherence picks Unicast listener + 1 for the second port. It has been implemented as a part of COH-3722.

Note that Coherence 3.6.1 and onwards will not have the NullPointerException but a more meaningful error message.

Solution

Separate nodes which run on the same machine by at least two ports.

For example:

When you specify localport=6000 for one node, it will also use port 6001.

The next node you can specify to use localport=6002 will also use 6003

Again the next node you can specify to use localport=6004 will also use 6005

etc

I reconfigured Unicast ports accordingly and the problem is solved!

Recursive Linux "Find Files Containing"

Wed, 06 Jan 2010 10:30:35 GMT

find . -name "*.ext" -exec grep -i -H -n "texttofind" {} ;

Problem testing Postfix

Thu, 10 Dec 2009 10:16:44 GMT

I am installing Postfix on my unmanaged VPS hosting machine and I am doing it first time ever. I followed the installation manual on Ubuntu site and everything looks all right except one tiny thing: I can’t send email using Telnet. Here is the response:

421 4.3.0 collect: Cannot write ./dfnBA9gfVO030273 (bfcommit, uid=0, gid=111): No such file or directory

I googled for an answer, but nothing useful came up so I tried to debug the problem myself. By looking into mail logs (/var/log/mail.log, found by examining /etc/syslog.conf) I found following strange response:

 start postfix/master[15758]: fatal: bind 0.0.0.0 port 25: Address already in use

That means only one thing: there is another process listening on this port. Hmm, what could it be? Sendmail, perhaps. I uninstalled it, according to guides I was using, but it was still running.

It’s time to stop it and start postfix!

sudo service sendmail stop



sudo service postfix restart

Problem solved!

Moved my blog

Tue, 01 Dec 2009 13:59:36 GMT

Moved my blog to a cheaper VPS. Also now this blog is served by Lighttpd instead of Apache. Everything seems to be a bit faster!

Trying Rational Team Concert

Mon, 27 Oct 2008 10:27:06 GMT

Image via CrunchBase

After rave reviews from my coworkers, who seen the IBM presentation, I decided to give it a try on my local machine. As it usually happens with IBM beta software, the expectancy of it working is close to zero. Let’s give it a try this time, could it be better?

First, I headed to http://jazz.net/ to download software. The server, obviously, managed by IBM marketing department, requires to register. Usual IBM ID is not supported, so I had to give IBM my email once again.

Since I only need a software for basic trial, I decided not to download version, which supports DB2 and Oracle databases. There is no support for MySQL either, but at least they promise to include Derby in setup package. So I pointed that I want Windows installation and found that download size is about 400Mb, and there is no IBM Download Manager (which I hate) to be seen.

So I downloaded and unpacked everything to my hard drive. I am on Windows and Windows users are used to find setup.exe, which does installation of the software for you. There is no such thing here: only install_express_c.html file, which describes step by step installation procedure for both Windows and Linux. Why Linux if I specifically stated that I want Windows installation?

First step says that I have to navigate to Tomcat’s folder and then run server.startup.bat file. There is no such file! The actual file named startup.bat. So I executed it, new command line window popped out and it is full of exceptions. Something about IbmX509 KeyStoreManager is nowhere to be found. Of course it can not be found because I am not running IBM JVM! What kind of assumption is to expect that everybody in the world are on IBM JVM, huh? I had to dig into Tomcat’s server.xml to set it to use Sun’s X509 keymanager (simply open tomcat/conf/server.xml, find IbmX509 and replace it with SunX509).

After quick restart Tomcat is happy and I can open, according to instructions, Jazz setup screen, which is a web application running within Tomcat. The setup has two options: “Fast Path” and “Custom setup”. I’ve chosen Fast Path because I am happy with the defaults, whatever they are. Click on “Fast Path” gets me to “Setup User Registry” screen, which has “A problem occurred while loading User Registry settings.” error message displayed. Hmm… Let’s head back to installation guide:

The default user name and password are case-sensitive:

The user name is ADMIN.

The password is ADMIN.

If you configured the LDAP directory Web container, log in with a JazzAdmin user that is defined in your LDAP directory.

What? I have to configure LDAP directory Web container first? This is first time it mentioned in this “guide”! How do I do that? There is no answer.

Ok, Fast Path is broken, so let’s try Custom setup. Click. “Loading Database Connection settings…” No progress here as well. Nothing about such problems in tomcat logs, nothing in server troubleshooting section of installation guide.

So there is no Rational Team Concert for me for now. Would I recommend it for use on my next project?

Update: Decided to dig around filesystem, looking for something useful like logs and other batch files. Found some logs in Tomcat cache folders (tomcat/work/Catalina/localhost) with the ClassNotFound messages. Found jars, containing missing class and added it to CLASSPATH. No help.

Then found mentioned above server.startup.bat and tried to run it. Now it complained about SunX509 KeyManager, so I returned the IbmX509 KeyManager back. Still no help progressing with Jazz Setup…

And then I decided to run repotools.bat – just in case the repository got corrupted or something. Execited it with parameter –createTables, it done something with something.

Tried Jass Setup page again and now it worked! Whoa!

Faces component: Table with subtotals

Fri, 09 Mar 2007 08:44:11 GMT

I tried to search all over the web for a Java Faces component, which will do a simple thing: totals and subtotals. And I failed. It seems that whole web is about how much more AJAX you could put everywhere, not how more useful your product could be for average user.

It could be done through a facet tag, which is obvious.

I think about that as competitive advantage for myself. If nobody done it - I should do it and be recognised for it!

Subversion and branching

Sun, 03 Dec 2006 10:11:31 GMT

Excellent article on branching in Subversion. One thing missing is the branch timeline chart. Something like this:

Where horisontal line is the trunk timeline and angled lines are releases. Based on my experience, that chart often helps developers to understand when branches are created and how to deal with them.

Ruby on Rails

Fri, 13 Oct 2006 19:07:21 GMT

Just made a configuration change on my hosting account: disabled Java in order to get Ruby-On-Rails

Decisions, decisions, decisions...

Fri, 13 Oct 2006 11:46:21 GMT

For a website I want to build, I have to choose the platform and the programming language. At work I use Java and Websphere 6, but can't use it for my own project. The reason is that I don't know how popular my service would be it seems quite expensive to put it into Websphere hosting. I have Java capabilities in my hosting plan here, but its only for web applications with no backend server support. In other words - there will be no MVC. Only JSPs and servlets.

And I will not be able to use JDK 5, nor be able to change server to, say, Glassfish, so I will be able to use some latest useful JSF components.

Another choice would be to choose other language, say Ruby. But I don't have any experience using it, so it would be a major roadblock for a starters.

I'm stuck again!