slony_logshipper TOOL

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.