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Big Data: A Brief Historical Description

Big data is a voluminous dataset from a variety of sources and of varying types that is continuously generated at a high velocity. It can only be managed by specialized processes different from the traditional relational database processing tools in order to infer any relevance or insight from it and to establish the veracity of the data. In other words, big data is a huge collection of data from different sources and of varying types that are growing at an exponential rate with time with no traditional means of storing or processing it but are valuable for insight. The description of big data above stems from the historical use of the term up to the recent definition of parameters (i.e. V's) that are being used to capture the various aspects of this sort of dataset. My history consideration for my description starts from various uses of the term between 1997 and 1998 which are similar to the current usage to mean information explosion starting with Michael Cox and David Ellsworth
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Catch persistence java.sql.sqlintegrityconstraintviolationexception

Depending on your persistence provider, you may encounter an SQLIntegrityConstraintViolationException when you try to persist an object that violates a database constraint. To handle this exception, you need to find out the class that wraps it by calling the e.getClass() and e.getCause() methods on the exception object. For example, if you are using Hibernate as your persistence provider, you can catch a  javax.ejb.EJBException  and then get the  org.hibernate.exception.ConstraintViolationException  from its cause. try{   //persistence transactions }catch (Exception e) {       if (e instanceof javax.ejb.EJBException) {       logger.debug("Exception instance of javax.ejb.EJBException");       Throwable cause = e.getCause(); //persistence exception          if (cause != null) {           cause = cause.getCause();          if (cause instanceof org.hibernate.exception.ConstraintViolationException)   {            logger.info("update_duplicate_response | " + update_

Quick Reminder: Golang subfolder import

Here is a tip for importing into your project. First, you import with the folder path but you use the declared package name in the imported class as the anchor to the methods in the imported class. For example, let's say you have your project in the following structure: example    main.go    pwd/       foldering.go To import foldering.go even if the package name declared in foldering.go is different e.g. secondPwd  into main.go main.go package main import (      "example/pwd" ) func main(){     secondPwd.PrintPWD(); } foldering.go package secondPwd import(      "os"      "fmt"      "log" ) //PrintPWD... func PrintPWD() {     dir, err := os.Getwd()      if err != nil {          log.Fatal(err)      }     fmt.Println(dir) }

Fix HTTP error code 513 on Wildfly

Description :  Many users have reported a network issue where they see a large number of connections in TIME_WAIT and IDLE states. This indicates that the connections are not being closed properly by the server or the client.  When I analyzed the network traffic, I found that the server was sending HTTP Error 513 to the client, which means that the server is overloaded and cannot handle more requests. The client was also logging a socket close event, which means that the client was terminating the connection. This can be simulated using Jmeter. The HTTP error code 153 resulted from the max concurrent connection limit reached, and the allowed queue was also full. This issue can cause performance degradation and resource wastage on both the server and the client. To resolve this issue, we recommend the following steps: Resolution :  1. Investigate the process of holding onto the connection longer than necessary. 2. Increase the server capacity or scale up the server to handle mo

Java Client SSL Setup and Related Errors

This article explains how to configure SSL for a Java client and how to troubleshoot some common errors that may occur during the process. To troubleshoot the issue effectively, please do the following: - Enable the JVM option -Djavax.net.debug=all - Capture the network traffic dump for faster analysis. Certificate Setup Go to your console and access your <JAVA_HOME>/bin/keytool NB :  The default location for saving the generated files is the user home directory. You can change this by specifying a path. STEP 1: Generate a new key (private key) for a Keystore. This either creates a file called <KEYSTORE_NAME>.keystore or update an existing file if it already exists. The CSR which will be presented to a Certificate Authority (CA) will be generated with this key and alias. <JAVA_HOME>/bin/keytool -genkey -alias <KEY_ALIAS> -keyalg RSA -key <KEYSTORE_NAME>.keystore -validity 3650 -keysize 2048 STEP 2: Generate a CSR file to be shared with t

ORA-12514: TNS:listener does not currently know of service requested in connect descriptor /ora-12505 tns listener does not currently know of sid

If you intend to connect with service name XE, edit your listener.ora to look include the XE name. Sample below SID_LIST_LISTENER =   (SID_LIST =   (SID_DESC =       (SID_NAME = XE)       (ORACLE_HOME = C:\oraclexe\app\oracle\product\11.2.0\server)     )     (SID_DESC =       (SID_NAME = PLSExtProc)       (ORACLE_HOME = C:\oraclexe\app\oracle\product\11.2.0\server)       (PROGRAM = extproc)     )     (SID_DESC =       (SID_NAME = CLRExtProc)       (ORACLE_HOME = C:\oraclexe\app\oracle\product\11.2.0\server)       (PROGRAM = extproc)     )   ) LISTENER =   (DESCRIPTION_LIST =     (DESCRIPTION =       (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))       (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))     )   ) DEFAULT_SERVICE_LISTENER = (XE) Open your command prompt as administrator and Run  lsnrctl restart lsnrctl reload Voila..Goodluck.

Not Able to Start OracleXNTNSListener in Windows Environment

To resolve this issue, Goto your oraclexe directory and navigate to network/ADMIN     e.g oraclexe\app\oracle\product\11.2.0\server\network\ADMIN Open ( listener .ora) in notepad and replace the HOST address with your localhost or current-ip e.g LISTENER =   (DESCRIPTION_LIST =     (DESCRIPTION =       (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))       (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))     )   ) DEFAULT_SERVICE_LISTENER = (XE) Open ( tnsnames .ora) with notepad and replace HOST address with your localhost or current-ip address. e.g XE =   (DESCRIPTION =     (ADDRESS = (PROTOCOL = TCP)(HOST =  localhost )(PORT = 1521))     (CONNECT_DATA =       (SERVER = DEDICATED)       (SERVICE_NAME = XE)     )   ) Open your command prompt as adminstrator and run  lsnrctl start NB: You might have to map localhost to 127.0.0.1 in the C:\Windows\System32\drivers\etc\host file by adding   127.0.0.1       localhost