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Testing Open Ports in Linux Testing open ports is a fundamental task in network troubleshooting and security assessment. While Telnet has been a traditional tool for this purpose, there are several alternatives available in Linux that offer similar functionality with added features and capabilities. I will share few ways and how they can be used to test open ports effectively. 1. Netcat (nc): Netcat is a versatile networking utility that can be used for reading from and writing to network connections using TCP or UDP. Its -z option allows you to scan for open ports without sending any data, making it a useful tool for testing port availability.  Example usage: nc -zv host_ip port Replace host_ip with the IP address or hostname of the target system and port with the port number you want to test. Output When Port Connection Working  Output When Port Connection Not  Working  2. Nmap: Nmap is a powerful network scanning tool that can be used to discover hosts and service...

Oracle Apps R12 Login Page showing a Blank page Error: We can see the below error in oacore application.log file javax.servlet.ServletException: oracle.classloader.util.AnnotatedClassNotFoundException: Missing class: _AppsLocalLogin This issue is caused due to missing class files in the OA_HTML directory. Solution: 1. Shutdown the application services 2. Compile the jsp’s manually using the below command perl $FND_TOP/patch/115/bin/ojspCompile.pl –compile –flush -p 2 3. Check whether all the jsp’s are getting compiled successfully 4. Restart the application services 5. Clear the browser cache If you like please follow and comment

joxcsys: release mismatch 12.1.0.2.0 1.6 in database (classes.bin) vs 12.1.0.2.191015 1.6 in executable  Error: In database alert log we can see continous below error. joxcsys: release mismatch 12.1.0.2.0 1.6 in database (classes.bin) vs 12.1.0.2.191015 1.6 in executable Solution: 1) Connect to database as sysdba 2) Replicate the issue SQL> select dbms_java.get_jdk_version() from dual; select dbms_java.get_jdk_version() from dual                                         * ERROR at line 1: ORA-29548: Java system class reported: release of Java system classes in the database (12.1.0.2.0 1.6) does not match that of the oracle executable (12.1.0.2.191015 1.6) 3) Run below script. SQL> @?/javavm/install/update_javavm_db.sql 4) Once above is completed, Please re-run below to validate. select dbms_java.get_jdk_version() from dual; DBMS_JAVA.GET_JDK_VERSION() ------------...

RMAN Backup Format Specifier Format specifiers in RMAN are placeholders that dynamically generate filenames and directory paths based on predefined patterns and parameters. They allow DBAs to define flexible naming conventions and storage locations for backup files, making it easier to organize and manage backup sets. Format specifiers are denoted by percent (%) signs followed by one or more characters representing specific attributes or values. For example, %t inserts a timestamp, %s inserts the backup set sequence number, and %d inserts the database name. The following substitiion variables can be used: %a Database Activition ID %b Base name - only vaied for SET NEWNAME and image copies %c Backup piece copy number %d Database name %D Day of month (DD) %e Archive log sequence number %f Absolute file number %F System-generated name. See below %h Archived redo log thread number %I DBID %M Month (MM) %N Tablespace name %n Database name - Right padded with 'x...

SQL Query to find Session In Oracle Database Not Active from 30 mins Query SELECT s.sid,        s.serial#,        s.username,        s.machine,        s.program,        s.status,        s.osuser,        s.logon_time,        s.last_call_et AS "Elapsed Time (sec)",        t.sql_text FROM   v$session s JOIN   v$sqltext t ON s.sql_address = t.address WHERE  s.type != 'BACKGROUND' AND    s.status = 'INACTIVE' AND    s.last_call_et > 1800; -- 30 minutes in seconds If you like please follow and comment

Moving RMAN backup from the OCI Standard Bucket to Archive Storage - Oracle Cloud Storing large volumes of database backups in Object Storage? Is the data seldom accessed or primarily intended for archival purposes? Now, with the introduction of Archive Storage, we have an opportunity to leverage a cost-effective, long-term, and secure storage solution. The key distinction between data backup and data archiving lies in the duration of data retention and the frequency of access. Archiving offers prolonged storage with infrequent access. Oracle offers Archive Storage as part of its Oracle Cloud Infrastructure Object Storage service, catering precisely to these requirements. By utilizing Archive Storage, we can retain database backups for extended periods without manual intervention, ensuring compliance with retention policies. Not only does this solution offer cost savings, but it also enables organizations to meet regulatory and compliance obligations effectively. In this blog post, we ...

Recovery from lost majority of voting disk CRS-1705 -  Recover the Voting disk   Error: While starting the services in cluster in Oracle Grid, Below error ws being observed. [cssd(2446)]CRS-1705:Found 1 configured voting files but 2 voting files are required, terminating to ensure data integrity; details at (:CSSNM00021:) in /u01/app/ocssd.log       Solution: 1) Stop the services on crs. [root@funoracledb ~]# crsctl stop crs -f CRS-2791: Starting shutdown of Oracle High Availability Services-managed resources on 'funoracledb' CRS-2673: Attempting to stop 'ora.mdnsd' on 'funoracledb' CRS-2673: Attempting to stop 'ora.cssdmonitor' on 'funoracledb' CRS-2673: Attempting to stop 'ora.crf' on 'funoracledb' CRS-2677: Stop of 'ora.cssdmonitor' on 'funoracledb' succeeded CRS-2677: Stop of 'ora.mdnsd' on 'funoracledb' succeeded CRS-2677: Stop of 'ora.crf' on 'funoracledb' succeeded CRS-2673...