NAME¶
slony_logshipping - slony_logshippping daemon
slony_logshipper is a tool designed to help apply logs. It runs as a daemon and
scans the archive directory for new .SQL files which it then applies to the
target database. It can be run with three sorts of parameters:
OPTIONS¶
- •
- Options, chosen from the following:
- •
- h
display this help text and exit
- •
- v
display program version and exit
- •
- q
quiet mode
- •
- l
cause running daemon to reopen its logfile
- •
- r
cause running daemon to resume after error
- •
- t
cause running daemon to enter smart shutdown mode
- •
- T
cause running daemon to enter immediate shutdown mode
- •
- c
destroy existing semaphore set and message queue (use with caution)
- •
- f
stay in foreground (don't daemonize)
- •
- w
enter smart shutdown mode immediately
- •
- A specified log shipper configuration file
This configuration file consists of the following specifications:
- •
- logfile = './offline_logs/logshipper.log';
Where the log shipper will leave messages.
- •
- cluster name = 'T1';
Cluster name
- •
- destination database = 'dbname=slony_test3';
Optional conninfo for the destination database. If given, the log shipper
will connect to this database, and apply logs to it.
- •
- archive dir = './offline_logs';
The archive directory is required when running in
‘database-connected’ mode to have a place to scan for
missing (unapplied) archives.
- •
- destination dir = './offline_result';
If specified, the log shipper will write the results of data massaging into
result logfiles in this directory.
- •
- max archives = 3600;
This fights eventual resource leakage; the daemon will enter ‘smart
shutdown’ mode automatically after processing this many
archives.
- •
- ignore table "public"."history";
One may filter out single tables from log shipped replication
- •
- ignore namespace "public";
One may filter out entire namespaces from log shipped replication
- •
- rename namespace "public"."history" to
"site_001"."history";
One may rename specific tables.
- •
- rename namespace "public" to "site_001";
One may rename entire namespaces.
- •
- post processing command = 'gzip -9 $inarchive';
Pre- and post-processing commands are executed via system(3).
An ‘@’ as the first character causes the exit code to be ignored.
Otherwise, a nonzero exit code is treated as an error and causes processing to
abort.
Pre- and post-processing commands have two further special variables defined:
- •
- $inarchive - indicating incoming archive filename
- •
- $outnarchive - indicating outgoing archive filename
- •
- error command = ' ( echo "archive=$inarchive" echo
"error messages:" echo "$errortext" ) | mail -s
"Slony log shipping failed" postgres@localhost ';
The error command indicates a command to execute upon encountering an error.
All logging since the last successful completion of an archive is
available in the $errortext variable.
In the example shown, this sends an email to the DBAs upon encountering an
error.
- •
- Archive File Names
Each filename is added to the SystemV Message queue for processing by a
slony_logshipper process.
