I own several old WRT routers and they still can be used for having fun. The following is a list of resources I frequently use. Must have reference to WRTRouters How to Recover from a bad flash The main resources site for Open WRT Hardware list for Linksys WRT54G, WRT54GL and WRT54GS An interesting forum… Read More: Blog Links: Resources for old WRT routers »
A very interesting post by Igor Minar on his blog on Configuring Common Access Log Format in GlassFish v2 and v3
Sometimes the db2 exceptions are cryptic or hidden by the application layer. In this case the only way to find the db2 SQL exception is to investigate in db2 logs. First check the log level setup in the Database Manager Configuration. Log in as the user under which db2 instance runs, in my case db2inst1.… Read More: DB2: Debug db2 SQL exceptions »
An EdgeRouter firmware update from 1.8.5 to 1.9 broke my L2TP based VPN. After the update my l2tp connection to local subnets was no longer working. Note that I have a load balancing setup with eth0 and eth1 being the load balanced WAN interfaces. It seems that due to the changes done for the l2tp… Read More: EdgeRouter: Force add the default routes to the load balanced… »
After seting up Security Onion as my home data center IDS (see https://blog.voina.org/data-center-ids-solution-using-security-onion/) I started to integrate monitoring of other resources to it. The first idea was to add the monitoring of my EdgeMax routers. Security Onion has a syslog-ng service that is able to receive client syslog data. Then we can visualize this data… Read More: Data Center: Add EdgeRouter logs to Security Onion »
An enterprise environment has to be monitored for external threats. There are a lot of very expensive IDS (Intrusion Detection System) that do this for you but you can set up in a production environment a very good solution for zero cost. The strength of an IDS is given by the IDS threats database, a… Read More: Data Center: IDS solution using Security Onion »
Sometimes we need to find specific things in application vast logs, sometimes 10 or 20 rotated logs each hundred of MBs each. For a quick search without using some specialized log viewer we can use the very powerful bash text processing commands. Problem: We have 10 log files each 100MB and we need to find… Read More: Linux: Search logs using bash tools »
In some cases while optimizing code to minimize the database footprint of a Java EE application we get to the point of trying to get rid of duplicate data. In a lot of cases several steps of the processing flow tend to store partially processed data or states of data and in a lot of… Read More: Java EE: Make an @Entity “empty” using a @Transient proxy »
Yet another thread of DB2 errors from an EJB application that connects to a DB2 instance. The reported thread of errors: [7/13/16 12:46:38:670 IST] 00000098 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions [jcc][t4][102][10040][4.19.26] Batch failure. The batch was submitted, but at least one exception occurred on an individual member of the batch. Use getNextException() to retrieve the exceptions… Read More: DB2: SQL Error: -803, SQLState: 23505, Unique Constraint Violation »
Sometimes Java and databases do not use the same standards to represent data. This can lead to strange exceptions for which sometimes can be hard to pin point the cause. We have the following Exception reported in the enterprise application log. Let’s analyse the errors. [7/13/16 12:46:32:752 IST] 00001456 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions SQL Error:… Read More: DB2: SQL Error: -803, SQLState: 23505 due to NON-UTF8 character… »