How to use crontab to rsync CCM log and out files

About CRON
cron is a unix utility that allows tasks to be automatically run in the background at regular intervals by the cron daemon. These tasks are often termed as cron jobs in unix.

Crontab Restrictions

You can execute crontab if your name appears in the file /usr/lib/cron/cron.allow. If that file does not exist, you can use
crontab if your name does not appear in the file /usr/lib/cron/cron.deny.
If only cron.deny exists and is empty, all users can use crontab. If neither file exists, only the root user can use crontab. The allow/deny files consist of one user name per line.
Crontab Commands
export EDITOR=vi specify a editor to open crontab file
crontab -e edit/create crontab file
crontab -l display your crontab file.
crontab -r remove your crontab file.
crontab -v * display the last time crontab file was edited
* This option is only available on a few systems.
Crontab syntax
A crontab file has five fields for specifying day, date and time followed by the command to be run at that interval.
* * * * * command to be executed- - - - -| | | | || | | | +----- day of week (0 - 6) (Sunday=0)| | | +------- month (1 - 12)| | +--------- day of month (1 - 31)| +----------- hour (0 - 23)+------------- min (0 - 59)
* in the value field above means all legal values as in braces for that column.
The value column can have a * or a list of elements separated by commas.
An element is either a number in the ranges shown above or two numbers in the range separated by a hyphen (meaning an inclusive range).

Note: The specification of days can be made in two fields: month day and weekday. If both are specified in an entry, they are cumulative meaning both of the entries will get executed .

Crontab Example
A line in crontab file like below removes the tmp files from /home/someuser/tmp each day at 6:30 PM.
30 18 * * * rm /home/someuser/tmp/*
Changing the parameter values as below will cause this command to run at different time schedule below :
min hour day/month month day/week Execution time
30 0 1 1,6,12 * At 00:30 Hrs on 1st of Jan, June & Dec.
:
0 20 * 10 1-5 At 8.00 PM every weekday (Mon-Fri) only in Oct.
:
0 0 1,10,15 * * At midnight on 1st ,10th & 15th of month
:
5,10 0 10 * 1 At 12.05,12.10 every Monday & on 10th of every month
:
Note : If you inadvertently enter the crontab command with no argument(s), do not attempt to get out with Control-d. This removes all entries in your crontab file. Instead, exit with Control-c.

Workshop Task - Establish log and out File Synchronization
In the workshop, the requirement is to synchronise the concurrent manager “log” and “out” files from the Primary to the Standby machine, every 15 minutes.

In this example, we are using the following machines:-
machine01.uk.oracle.com is machine A (Primary machine)

machine02.uk.oracle.com is machine B (Standby machine)

On the Standby machine:
mkdir -p /log
mkdir -p /out

mkdir -p /oracle/PROD/inst/apps/PROD_machine01/logs/appl/conc/log
mkdir -p /oracle/PROD/inst/apps/PROD_machine01/logs/appl/conc/out

On the Primary Machine
mkdir -p /log
mkdir -p /out

mkdir -p /oracle/PROD/inst/apps/PROD_machine02/logs/appl/conc/log
mkdir -p /oracle/PROD/inst/apps/PROD_machine02/logs/appl/conc/out

From machine A
We will be pushing files from machine A every 30 minutes, on the hour and half hour, so our entries will be:
$ crontab -e

#
## Push log and out files from this machine to machine02 every 30 minutes, on the hour and half hour
#
00,30 * * * * rsync -av /oracle/PROD/inst/apps/PROD_machine01/logs/appl/conc oracle@machine02: /oracle/PROD/inst/apps/PROD_machine01/logs/appl --rsync-path=/usr/bin/rsync >> /tmp/rsync_01_00-30.log
#

As crontab uses “vi” syntax, save changes using :wq!

From machine B
We will also be pushing files from machine B every 30 minutes, on the quarter hour and three quarter hour, so our entries will be:
#
## Push log and out from this machine to machine01 every 30 minutes at quarter past, and quarter to.
#
15,45 * * * * rsync -av /oracle/PROD/inst/apps/PROD_machine02/logs/appl/conc oracle@machine01:/oracle/PROD/inst/apps/PROD_machine02/logs/appl --rsync-path=/usr/bin/rsync >> /tmp/rsync_01_15-45.log
#