Linux: Generating SSH Keys

One of my colleagues asked if there's a way to log into a remote machine using SSH without a prompting for a password. A script was being written to check the load remotely. I told him to generate SSH keys for the user that will be running the command and copy that key to the other machine. For example, I have to machines and I want them to be cross checking each other (for some reason). Let's call them Server01 and Server 02.

MySQL: Duplicate Entry Error on Slave

While doing a normal routine check on the MySQL databases, one of the slave was reporting an error:

Duplicate entry '999' for key 'PRIMARY' on query. Default database...

To resolve this problem, we can set the parameter sql_slave_skip_counter to 1:

mysql> stop slave;

mysql> set global sql_slave_skip_counter=1;

mysql> start slave;

This will ignore the error that was encountered and just continue replicating.

MySQL: Relocating Slave Logs

On a master-slave configuration, MySQL creates binary logs on the master and events recorded in these files are read by the slave and stores them in relay logs. These log files are stored in the data directory by default. However, they can be relocated to another location for optimization purposes. 

Oracle: ORA-24247: network access denied by access control list (ACL)

I created a SOLR utility package in Oracle but was getting an HTTP request failed error during run time.

Oracle: Determine OS Process Id based on Oracle Process Id

To get the OS process Id of an Oracle process, join the v$session and v$process views:

select vp.spid "OS Id", vs.sid "Oracle Id", vs.username, vs.osuser

from v$process vp, v$session vs

where vp.addr = vs.paddr;