http://www.randombugs.com Just another Bastard Operator From Hell. Everything from *nix to programming Thu, 06 May 2010 14:21:46 +0000 en hourly 1 http://wordpress.org/?v=3.0 http://www.randombugs.com/linux/crash-innodb-table.html http://www.randombugs.com/linux/crash-innodb-table.html#comments Thu, 06 May 2010 14:16:10 +0000 admin http://www.randombugs.com/?p=658
I searched over internet, on several tens of posts, to find how to delete a crashed Innodb table. Short story: I tried to import a big table but it crashed in the middle of the process (power failure). The table was not very important so I didn’t care about the table, I just want to delete it and start from the scratch, but surprise! The table cannot be deleted! I use the latest MySQL Innodb plugin from Debian backports repository (is coming with Debian 5.1.xx) with file per table ...]]> http://www.randombugs.com/linux/crash-innodb-table.html/feed 0 http://www.randombugs.com/linux/compile-configure-modqos-prevent-slowloris-ddos-apache-2-debian-lenny-distribution.html http://www.randombugs.com/linux/compile-configure-modqos-prevent-slowloris-ddos-apache-2-debian-lenny-distribution.html#comments Tue, 04 May 2010 20:00:13 +0000 admin http://www.randombugs.com/?p=650
mod_qos is becoming a very popular module for Apache, from the discover of Slowloris DDoS Attack. It seems, mod_qos is the best solution for Slowloris attack on Apache 2, but you can also check mod_evasive, mod_security or http accelerator “Varnish”. In this post I will try to present a step by step tutorial how to install mod_qos and configure to prevent Slowloris DDoS attack. This post is just a compendium of other good posts: How To Defend slowloris DDoS With mod_qos (Apache2 On Debian [Lenny]) DDoS, Apache2 and mod_qos How to best defend ...]]> http://www.randombugs.com/linux/compile-configure-modqos-prevent-slowloris-ddos-apache-2-debian-lenny-distribution.html/feed 0 http://www.randombugs.com/linux/contentfilter-unsolicited-bulk-email.html http://www.randombugs.com/linux/contentfilter-unsolicited-bulk-email.html#comments Tue, 16 Mar 2010 14:07:18 +0000 admin http://www.randombugs.com/?p=643
After an Amavis upgraded my e-mail system started to have a strange behavior. A lot of emails sent internally from one user to another stopped with the following message: ——– Original Message ——– Subject: Considered UNSOLICITED BULK EMAIL, apparently from youis considered local. Date: Tue, 13 Mar 2010 00:13:39 +0200 (EET) From: Content-filter at xxx13.randombugs.com To: A message from to: -> yyy@randombugs.com was considered unsolicited bulk e-mail (UBE). Our internal reference code for your message is 00311-13/npX-RCahiLdc The message carried your return address, so it was either a genuine mail from you, or a sender address was faked and ...]]> http://www.randombugs.com/linux/contentfilter-unsolicited-bulk-email.html/feed 0 http://www.randombugs.com/java/glassfish/glassfish-cluster-211-httpsessions-replication-multithread-concurrent-access.html http://www.randombugs.com/java/glassfish/glassfish-cluster-211-httpsessions-replication-multithread-concurrent-access.html#comments Wed, 03 Mar 2010 10:07:06 +0000 admin http://www.randombugs.com/?p=634
I have several clusters with Glassfish 2.1.1 in a BIG virtual environment and all worked fine … until I add new processors to this clusters. After upgrade, I started to have problems with HttpSession replication. Starting debugging JXTA, Shoal and the Web Container didn’t help at all. Until I found this page Memory Replication & Multi-threaded Concurrent Access to HttpSessions. My applications was doing multi-thread concurrent access some times (Ajax) and this was the root cause of all lost sessions. I modified sun-web.xml from my application, accordingly with the ...]]> http://www.randombugs.com/java/glassfish/glassfish-cluster-211-httpsessions-replication-multithread-concurrent-access.html/feed 0 http://www.randombugs.com/java/java-networking-problems-debian-squeezesid.html http://www.randombugs.com/java/java-networking-problems-debian-squeezesid.html#comments Tue, 16 Feb 2010 08:46:07 +0000 admin http://www.randombugs.com/?p=630
After upgrading to the latest version of Debian squeeze/sid, I was not able to use the networking in java. If you get: [2/16/10 10:39 AM] Exception occurred: java.net.SocketException: Network is unreachable at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333) at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) at java.net.Socket.connect(Socket.java:525) then you should disable ipv6. To do that ...]]> http://www.randombugs.com/java/java-networking-problems-debian-squeezesid.html/feed 0 http://www.randombugs.com/java/glassfish/changing-logging-system-glassfish-21.html http://www.randombugs.com/java/glassfish/changing-logging-system-glassfish-21.html#comments Mon, 28 Sep 2009 18:04:20 +0000 admin http://www.randombugs.com/?p=606
A lot of people are not satisfied by the default Java Logging (JUL) in Glassfish. Also, myself I encountered some problems on clustered environments where we should have one single log and not one log for each instance. Trying to change the logging system in Glassfish it looks to be almost impossible , but I found a very interesting project java.util.logging to log4j Bridge and the sky become more clear for Glassfish logging. Jul to Log4J Bridge are part of log4J project and is very useful when you ...]]> http://www.randombugs.com/java/glassfish/changing-logging-system-glassfish-21.html/feed 0 http://www.randombugs.com/java/dbappender-log4j-12.html http://www.randombugs.com/java/dbappender-log4j-12.html#comments Thu, 24 Sep 2009 20:19:46 +0000 admin http://www.randombugs.com/?p=595
Initially, DBAppender for Log4j was introduced in version 1.3 of Log4j, but this version was ABANDONED by Apache team. DBAppender is very useful when we want to send our log on a JNDI resource and not on standard JDBC or file. If you need just logging in a database for your application, then you should use JDBCAppender. If you want to log on a JNDI or Database Connection Pool the DBAppender is for you. In this post I will show you how to get, compile and quick test the DBAppender. 1. ...]]> http://www.randombugs.com/java/dbappender-log4j-12.html/feed 5 http://www.randombugs.com/java/javalangsecurityexception-jce-authenticate-provider-bc.html http://www.randombugs.com/java/javalangsecurityexception-jce-authenticate-provider-bc.html#comments Mon, 10 Aug 2009 09:57:57 +0000 admin http://www.randombugs.com/?p=577
Trying to integrate BouncyCastle Cryptography provider in Java can be a nightmare. I read a lot of forums messages about “JCE cannot authenticate the provider BC” and I didn’t find any clear response. After several hours of tweaking and digging I found the main reason of the problem. If you want to use BouncyCastle as Security provider then install it directly on your Java Virtual Machine and remove any library of bc from your application. How to install correctly Bouncy Castle on your JVM: First for Ubuntu/Debian users you should look ...]]> http://www.randombugs.com/java/javalangsecurityexception-jce-authenticate-provider-bc.html/feed 3 http://www.randombugs.com/linux/tuning-linux-system-database.html http://www.randombugs.com/linux/tuning-linux-system-database.html#comments Thu, 16 Jul 2009 17:24:13 +0000 admin http://www.randombugs.com/?p=567
In my experiments with databases I was constrained to tune the system together with the databases. A system what will run a database is quite different from any other server system, because databases put a lot of stress on the IO and especially on the disks (probably the file servers too). Hardware is not all you should tune your system as much as possible. In this post I will talk about Linux with Ext3 (is what I have right now), but on future I will test OpenSolaris with ZFS. 1. ...]]> http://www.randombugs.com/linux/tuning-linux-system-database.html/feed 2 http://www.randombugs.com/linux/compiling-sysbench-0412-debian.html http://www.randombugs.com/linux/compiling-sysbench-0412-debian.html#comments Thu, 09 Jul 2009 14:09:09 +0000 admin http://www.randombugs.com/?p=556
On the Linux market are a lot of distributions and every distribution is unique in his way. Is normal to have different compilers and tools from distribution to distribution so is almost normal to have programs what doesn’t compile on all distributions. sysbench 0.4.12 is one of them. Anyway the solution is simple and I will describe it very quickly how to compile sysbench under Debian. Probably it will work for other distributions if you have the same problem. Let’s start with the error. I run the normal steps to ...]]> http://www.randombugs.com/linux/compiling-sysbench-0412-debian.html/feed 9