Subject:
pgagent howto
From:
Fernando Paredes Garcia ####@####.####
Date:
13 Feb 2006 20:26:36 -0000
Message-Id: <43F0EB75.4040306@mail.com>
hello:
this is a suggestion of pgagent howto.
*first: this is copied from the pgadmin III help*
pgAgent Installation
pgAgent runs as a daemon on *nix systems, and a service on Windows
systems. In the majority of cases it will run on the database server
itself - it is for this reason that pgAgent is not automatically setup
when pgAdmin is installed. In some cases however, it may be preferable
to run pgAgent on multiple systems, against the same database -
individual jobs may be targetted at a particular host, or left for
execution by any host. Locking prevents execution of the same instance
of a job by multiple hosts.
Database setup
pgAgent stores it's configuration in the "postgres" database in your
cluster. This database exists by default in PostgreSQL 8.1 versions, for
earlier versions you need to create the database yourself. The database
must have the pl/pgsql procedural language installed - PostgreSQL's
'createlang' program can do this if required.
Once created, connect to the new database, and open the SQL tool. Select
the File -> Open option from the menu and find the 'pgagent.sql' script
installed with pgAdmin. The installation location for this file varies
from operating system to operating system, however it will normally be
found under 'C:\Program files\pgAdmin III' on Windows systems (or
'C:\Program files\PostgreSQL\8.x\pgAdmin III' if installed with the
PostgreSQL server installer), or '/usr/local/pgadmin3/share/pgadmin3' or
'/usr/share/pgadmin3' on *nix systems. Once the file is loaded, click
the 'Run' button to execute the script.
The script will create a number of tables and other objects in a schema
called 'pgagent'.
Daemon installation on *nix
To install the pgAgent daemon on a *nix system, you will normally need
to have root privileges to modify the system startup scripts - doing so
is quite system specific so you should consult your system documentation
for further information.
The program itself takes few command line options - most of which are
only needed for debugging or specialised configurations:
Usage:
/path/to/pgagent [options] <connect-string>
options:
-f run in the foreground (do not detach from the terminal)
-t <poll time interval in seconds (default 10)>
-r <retry period after connection abort in seconds (>=10, default 30)>
-l <logging verbosity (ERROR=0, WARNING=1, DEBUG=2, default 0)>
The connect string required is a standard PostgreSQL libpq connection
string (see the PostgreSQL documentation for further details). For
example, the following command lilne will run pgAgent against a server
listening on the localhost, using a database called 'pgadmin',
connecting as the user 'postgres':
/path/to/pgagent hostaddr=127.0.0.1 dbname=pgadmin user=postgres
Service installation on Windows
pgAgent is able to self-install itself as a service on Windows systems.
The command line options available are similar to those on *nix systems,
but include an additional parameter to tell the service what to do:
Usage:
"C:\Program Files\pgAdmin III\pgAgent" REMOVE <serviceName>
"C:\Program Files\pgAdmin III\pgAgent" INSTALL <serviceName> [options]
<connect-string>
options:
-u <user or DOMAIN\user>
-p <password>
-d <displayname>
-t <poll time interval in seconds (default 10)>
-r <retry period after connection abort in seconds (>=10, default 30)>
-l <logging verbosity (ERROR=0, WARNING=1, DEBUG=2, default 0)>
The service may be quite simply installed from the command line as follows:
"C:\Program Files\pgAdmin III\pgAgent" INSTALL pgAgent -u postgres -p
secret hostaddr=127.0.0.1 dbname=pgadmin user=postgres
The service may then be started from the command line using net start
pgAgent, or from the Services control panel applet. Any logging output
or errors will be reported in the Application event log.
Security concerns
pgAgent is a very powerful tool, but does have some security
considerations that you should be aware of:
Database password - DO NOT be tempted to include a password in the
pgAgent connection string - on *nix systems it may be visible to all
users in 'ps' output, and on Windows systems it will be stored in the
registry in plain text. Instead, use a libpq ~/.pgpass file to store the
passwords for every database that pgAgent must access. Details of this
technique may be found in the PostgreSQL documentation.
System/database access - all jobs run by pgAgent will run with the
security privileges of the pgAgent user. SQL steps will run as the user
that pgAgent connects to the database as, and batch/shell scripts will
run as the operating system user that the pgAgent service or daemon is
running under. Because of this, it is essential to maintain control over
the users that are able to create and modify jobs. By default, only the
user that created the pgAgent database objects will be able to do this -
this will normally be the PostgreSQL superuser.
*second: init script written by me*
file: /etc/init.d/pgagent
#!/bin/sh
# Copyright (c) 2006 Fernando Paredes Garcia Cusco-Peru.
# All rights reserved.
#
# Author: Fernando Paredes Garcia
# Please send feedback to ####@####.####
#
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# System startup script for PgAgent
#
#
#
### BEGIN INIT INFO
# Provides: pgagent
# Required-Start: $network $remote_fs
# Required-Stop:
# Default-Start: 3 5
# Default-Stop:
# Description: Start the PgAdmin daemon
### END INIT INFO
pga_path=/usr/bin/
pga_filename=pgagent
conn_string=hostaddr=192.168.1.7 user=postgres password=1234
dbname=postgres
pga_logfile=/var/log/pgagent.log
pga_pidfile=/var/run/$pga_filename.pid
case "$1" in
start)
echo 'PgAgent starting...'
#I can't understand why stdout sents nothing to log file
$pga_path$pga_filename -l2 -f $conn_string > $pga_logfile &
#i'm sure there is a safer method to do it
echo $! > $pga_pidfile
echo 'Done!'
;;
stop)
#a dangerous kill, how can this script answer for running tasks?
kill `cat $pga_pidfile`
rm -f $pga_pidfile
echo 'PgAgent stopped!'
;;
restart)
kill `cat $pga_pidfile`
rm -f $pga_pidfile
echo 'PgAgent stopped!'
echo 'PgAgent starting...'
$pga_path$pga_filename -l2 -f $conn_string > $pga_logfile &
echo $! > $pga_pidfile
echo 'Done!'
esac
*third: example*
before:
- be sure you have installed postgresql >= 8.0
- be sure you are using pgadmin III >= 1.3
- be sure you create the database named: postgres
- be sure you run the pgagent.sql script in the database named: postgres
- be sure you specify "postgres" in the "Mainteance DB" field
pre-requisites:
a test function with its table. execute this scripts INTO YOUR TARGET
DATABASE (NOT DATABASE postgres)
CREATE OR REPLACE FUNCTION fun_table01()
RETURNS bool AS
$BODY$
begin
insert into table01
select random(),now();
if found then
return true;
end if;
return false;
end;
$BODY$
LANGUAGE 'plpgsql' VOLATILE;
CREATE TABLE table01
(
col01 text,
col02 text
)
WITHOUT OIDS;
testing:
job creation
1. right click Jobs, click New Job
2. fill name field. ie: test1
3. click button OK
schedule creation
1. right click schedule(into new job), click new schedule
2. fill name field. ie: programation
3. change the end date field, i suggest one day after start date
4. click button OK
step creation
1. right click step (into new job), click new job
2. fill name field. ie: execution
3. IMPORTANT: select the TARGET DATABASE
4. go to definition tab.
5. write: select fun_table01();
6. click button OK
wait at least 3 minutes and check the table you create before.
THATS ALL!
-------------------
I know it needs a ldp documentation formatting, language etc. I'm sorry
i'm natural language speaker.
Good bless you all!