cluster-sync — tool for synchronizing files between cluster members
cluster-sync [-n] [-d
debug_level] -c
cfg
This script performs file synchronization between exactly two (cluster) members.
This script is expected to be executed regularly (i.e. from
crontab). It connects to the remote host, looks for changes made on the
watched files and transfers the changes from one host to the other.
If the file is changed on both hosts, it is considered as the conflict.
It is specified in the configuration, which side is prefered in
conflicts (CONFLICT_WINNER) below.
The hosts are expected to be interconnected by
icamd/icasd daemons. See REMOTE_HOST
below.
The values given on the command line have precedence over values given in the configuraiton file.
-cThe configuration file to be used.
-dThe debug level. Default is 6 (LOG_INFO). Increase it for more verbose logging. The script logs to stdout and to /var/log/kernun-debug.
-nPerform a 'dry run'. No sync actions are performed, just log what would be done.
At least REMOTE_HOST and
INCLUDE must be given. If the option can be
specified both in configuration file and on command line, the
command line value takes precedence.
REMOTE_HOST=TARGETThe ssh target to be used when invoking commands on the other host.
Be sure to use the name defined in
/etc/sshd/ssh_config.
There are many commands executed on the REMOTE
host, so it is necessary for them to be executed
quickly. Daemons icamd/icasd provide
fast connections since it takes advantage of the ssh
ControlPath feature.
INCLUDE="PATH1"[, "PATH2", ...]The list of the included files, directories or patterns. The absolute path is given, and it must be preceeded by symbol '.'.
Example:
INCLUDE="./var/log/kernun-stats.*.bz2", "./data/fake-cert/fake_ca/C*.*"
The values must be written in a comma separated list on a single row.
PRECMD="command"The command is executed to determine whether
perform the synchronization or not. Use
PRECMD to prevent synchronization when
it is not desired. For example when the cluster is
degraded.
The command can either be a script name or a simple shell script. It is passed to the perl 'system' call.
No PRECMD is performed by
default.
MINIMAL_AGE=secondsOnly files that are older that MINIMAL_AGE are taken in account. This should prevent repetitious copying of the files that are being written for longer period (for examples the zipped logs).
Defaults to 0 (the files are synchronized regardless of their age).
LOCK=filenameThe lock file to be locked in order to start the synchronisation. If the lock cannot be (exclusively) locked, the scripts exits immediately.
By default, the lock prevents the script to run more than once in parallel. It can also be used by other programs not to run simultaneously.
CONFLICT_WINNER={LOCAL|REMOTE}Should the conflict appear, this option specifies whos change wins. Defaults to LOCAL.
RM_STALED={0|1}Whether the staled temporary file should be automatically removed. Defaults to 1.
DRY_RUN={0,1}Perform a 'dry run'. No sync actions are performed, just log what would be done.
DEBUG_LEVEL=numThe debug level. Default is 6 (LOG_INFO). Increase it for more verbose logging. The script logs to stdout and to /var/log/kernun-debug.