Web Server A Web Server can resolve (handles) HTTP request (protocol). When the web server received a HTTP request, it will return a HTTP response to clients, for example sent back a HTML page? We will further illustrate this process, when a request is sent to the Web server where came, it only simply put … Continue reading
To use the Multipath and Udev, we have to understand what are they, why we want to use it. What is ‘Device Mapper Multipath’ (multipath I/O)? Device Mapper Multipath（DM-Multipath）can configure muliple I/O links between the server nodes to SAN as a single device. These I/O links might consist with various cables, switches and SCSI controllers … Continue reading
This a good example of the co-related query. For example we have table with 5 employees and their salary. If we want to query the employee with second highest salary, we can use the query below.
ORA-15055: unable to connect to ASM instance and ORA-12547: TNS:lost contact After completed to installation of the Oracle RAC, I got following error when I try restart the database Check the alert log file, I found following errors Errors in file /oragi/app/oracle/diag/rdbms/rac/rac1/trace/rac1_asmb_31756.trc: Check the asm instance，the status of the asm diskgroup shows online： Check the … Continue reading
When the Oracle database fail to allocate the next extent to the sys.aud$ table, all users will not able login to the database remotely. The solution of the issue is to relocate the sys.aud$ table to a dedicated tablespace and shrink the sys.aud$ table regularly. There are some reasons for DBAs to relocated the sys.aud$ … Continue reading