NuxOra – Linux and Oracle IT website

Pré-requis
Serveur Apache + PHP avec Nagios installé

>>> I. Configuration principale

Nous l’avions vu dans la premeire partie, le configuration de Nagios est rassemblée dans un dossier unique situé sous etc/
Le fichier de configuration principal est etc/nagios.cfg étroitement lié aux CGIs, ces deux fichiers constituent le coeur de la configuration Nagios et liste egalement les autres fichiers de configuration qui seront utilisés:
Voici la liste des principaux fichiers de configuration:
cgi.cfg
commands.cfg
contactgroups.cfg
contacts.cfg
hostgroups.cfg
hosts.cfg
htpasswd.users
nagios.cfg
resource.cfg
servicegroups.cfg
services.cfg
timeperiods.cfg

Le fichier main.cfg reprend les elements pricnipaux

# NAGIOS USER
# This determines the effective user that Nagios should run as.
# You can either supply a username or a UID.
nagios_user=nagios

# NAGIOS GROUP
# This determines the effective group that Nagios should run as.
# You can either supply a group name or a GID.
nagios_group=nagios

ou par exemple:

# EXTERNAL COMMAND FILE
# This is the file that Nagios checks for external command requests.
# It is also where the command CGI will write commands that are submitted
# by users, so it must be writeable by the user that the web server
# is running as (usually ‘nobody’).  Permissions should be set at the
# directory level instead of on the file, as the file is deleted every
# time its contents are processed.

command_file=/usr/local/nagios/var/rw/nagios.cmd

De meme le fichier cgi.cfg regroupe les informations essentielles àà l’interface web ainsi que celles liées à la sécurité de l’interface.

# PHYSICAL HTML PATH
# This is the path where the HTML files for Nagios reside.  This
# value is used to locate the logo images needed by the statusmap
# and statuswrl CGIs.
physical_html_path=/usr/local/nagios/share

# URL HTML PATH
# This is the path portion of the URL that corresponds to the
# physical location of the Nagios HTML files (as defined above).
# This value is used by the CGIs to locate the online documentation
# and graphics.  If you access the Nagios pages with an URL like
# http://www.myhost.com/nagios, this value should be ‘/nagios’
# (without the quotes).
url_html_path=/nagios

# SYSTEM/PROCESS COMMAND ACCESS
# This option is a comma-delimited list of all usernames that
# can issue shutdown and restart commands to Nagios via the
# command CGI (cmd.cgi).  Users in this list can also change
# the program mode to active or standby. By default, *no one*
# has access to this unless you choose to not use authorization.
# You may use an asterisk (*) to authorize any user who has
# authenticated to the web server.
authorized_for_system_commands=nagiosadmin

# GLOBAL HOST/SERVICE VIEW ACCESS
# These two options are comma-delimited lists of all usernames that
# can view information for all hosts and services that are being
# monitored.  By default, users can only view information
# for hosts or services that they are contacts for (unless you
# you choose to not use authorization). You may use an asterisk (*)
# to authorize any user who has authenticated to the web server.
authorized_for_all_services=nagiosadmin,guest,nagios,guest
authorized_for_all_hosts=nagiosadmin,guest,nagios,guest

# user who has authenticated to the web server.
authorized_for_all_service_commands=nagiosadmin
authorized_for_all_host_commands=nagiosadmin

>>> II. Configuration des serveurs

L’execution du ./configure avant compilation crée les fichiers samples. Ces derniers sont disponibles apres la compilation en executant la commande suivante: make install-config
Je ne vais pas decrire le contenu des fichiers ici, parmi les fichiers samples générés, prenons celui du localhost (ci dessous) Il en resulte une multitude de définition d’objets: periode de temps, nom de serveur, service, groupe de serveur, contact. Chacun des paragraphes ci dessous va definir une entité, qui elle meme appartiendra ou sera liée à une autre entité. Un serveur appartiendra à un groupe de serveur. Un serveur sera lié à un contact ou un groupe de contact qui lui meme contiendra des contacts. La syntaxe est relativement simple, ladocumentation nagios et l’example ci dessous suffiront pour débuter

###############################################################################
# LOCALHOST.CFG – SAMPLE OBJECT CONFIG FILE FOR MONITORING THIS MACHINE
#
# Last Modified: 11-27-2006
#
# NOTE: This config file is intended to servce as an *extremely* simple
#       example of how you can create your object configuration file(s).
#
###############################################################################

###############################################################################
###############################################################################
#
# TIME PERIODS
#
###############################################################################
###############################################################################

# This defines a timeperiod where all times are valid for checks,
# notifications, etc.  The classic “24×7″ support nightmare.

define timeperiod{
timeperiod_name 24×7
alias           24 Hours A Day, 7 Days A Week
sunday          00:00-24:00
monday          00:00-24:00
tuesday         00:00-24:00
wednesday       00:00-24:00
thursday        00:00-24:00
friday          00:00-24:00
saturday        00:00-24:00
}

# ‘workhours’ timeperiod definition
define timeperiod{
timeperiod_name workhours
alias           “Normal” Working Hours
monday          09:00-17:00
tuesday         09:00-17:00
wednesday       09:00-17:00
thursday        09:00-17:00
friday          09:00-17:00
}

# ‘nonworkhours’ timeperiod definition
define timeperiod{
timeperiod_name nonworkhours
alias           Non-Work Hours
sunday          00:00-24:00
monday          00:00-09:00,17:00-24:00
tuesday         00:00-09:00,17:00-24:00
wednesday       00:00-09:00,17:00-24:00
thursday        00:00-09:00,17:00-24:00
friday          00:00-09:00,17:00-24:00
saturday        00:00-24:00
}

# ‘none’ timeperiod definition
define timeperiod{
timeperiod_name none
alias           No Time Is A Good Time
}

###############################################################################
###############################################################################
#
# COMMANDS
#
###############################################################################
###############################################################################

# NOTE: Sample command definitions can now be found in the sample commands.cfg
#       file

###############################################################################
###############################################################################
#
# CONTACTS
#
###############################################################################
###############################################################################

# In this simple config file, a single contact will receive all alerts.
# This assumes that you have an account (or email alias) called
# “nagios-admin” on the local host.

define contact{
contact_name                    nagios-admin
alias                           Nagios Admin
service_notification_period     24×7
host_notification_period        24×7
service_notification_options    w,u,c,r
host_notification_options       d,r
service_notification_commands   notify-by-email
host_notification_commands      host-notify-by-email
email                           nagios-admin@localhost
}

###############################################################################
###############################################################################
#
# CONTACT GROUPS
#
###############################################################################
###############################################################################

# We only have one contact in this simple configuration file, so there is
# no need to create more than one contact group.

define contactgroup{
contactgroup_name       admins
alias                   Nagios Administrators
members                 nagios-admin
}

###############################################################################
###############################################################################
#
# HOSTS
#
###############################################################################
###############################################################################

# Generic host definition template – This is NOT a real host, just a template!

define host{
name                            generic-host    ; The name of this host template
notifications_enabled           1               ; Host notifications are enabled
event_handler_enabled           1               ; Host event handler is enabled
flap_detection_enabled          1               ; Flap detection is enabled
failure_prediction_enabled      1               ; Failure prediction is enabled
process_perf_data               1               ; Process performance data
retain_status_information       1               ; Retain status information across program restarts
retain_nonstatus_information    1               ; Retain non-status information across program restarts
notification_period             24×7            ; Send host notifications at any time
register                        0               ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL HOST, JUST A TEMPLATE!
}

# Linux host definition template – This is NOT a real host, just a template!

define host{
name                            linux-server    ; The name of this host template
use                             generic-host    ; This template inherits other values from the generic-host template
check_period                    24×7            ; By default, Linux hosts are checked round the clock
max_check_attempts              10              ; Check each Linux host 10 times (max)
check_command                   check-host-alive ; Default command to check Linux hosts
notification_period             workhours       ; Linux admins hate to be woken up, so we only notify during the day
; Note that the notification_period variable is being overridden from
; the value that is inherited from the generic-host template!
notification_interval           120             ; Resend notification every 2 hours
notification_options            d,u,r           ; Only send notifications for specific host states
contact_groups                  admins          ; Notifications get sent to the admins by default
register                        0               ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL HOST, JUST A TEMPLATE!
}

# Since this is a simple configuration file, we only monitor one host – the
# local host (this machine).

define host{
use                     linux-server            ; Name of host template to use
; This host definition will inherit all variables that are defined
; in (or inherited by) the linux-server host template definition.
host_name               localhost
alias                   localhost
address                 127.0.0.1
}

###############################################################################
###############################################################################
#
# HOST GROUPS
#
###############################################################################
###############################################################################

# We only have one host in our simple config file, so there is no need to
# create more than one hostgroup.

define hostgroup{
hostgroup_name  test
alias           Test Servers
members         localhost
}

###############################################################################
###############################################################################
#
# SERVICES
#
###############################################################################
###############################################################################

# Generic service definition template – This is NOT a real service, just a template!

define service{
name                            generic-service         ; The ‘name’ of this service template
active_checks_enabled           1                       ; Active service checks are enabled
passive_checks_enabled          1                       ; Passive service checks are enabled/accepted
parallelize_check               1                       ; Active service checks should be parallelized (disabling this can lead to major performance problems)
obsess_over_service             1                       ; We should obsess over this service (if necessary)
check_freshness                 0                       ; Default is to NOT check service ‘freshness’
notifications_enabled           1                       ; Service notifications are enabled
event_handler_enabled           1                       ; Service event handler is enabled
flap_detection_enabled          1                       ; Flap detection is enabled
failure_prediction_enabled      1                       ; Failure prediction is enabled
process_perf_data               1                       ; Process performance data
retain_status_information       1                       ; Retain status information across program restarts
retain_nonstatus_information    1                       ; Retain non-status information across program restarts
is_volatile                     0                       ; The service is not volatile
register                        0                       ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}

# Local service definition template – This is NOT a real service, just a template!

define service{
name                            local-service           ; The name of this service template
use                             generic-service         ; Inherit default values from the generic-service definition
check_period                    24×7                    ; The service can be checked at any time of the day
max_check_attempts              4                       ; Re-check the service up to 4 times in order to determine its final (hard) state
normal_check_interval           5                       ; Check the service every 5 minutes under normal conditions
retry_check_interval            1                       ; Re-check the service every minute until a hard state can be determined
contact_groups                  admins                  ; Notifications get sent out to everyone in the ‘admins’ group
notification_options            w,u,c,r                 ; Send notifications about warning, unknown, critical, and recovery events
notification_interval           60                      ; Re-notify about service problems every hour
notification_period             24×7                    ; Notifications can be sent out at any time
register                        0                       ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}

# Define a service to “ping” the local machine

define service{
use                             local-service         ; Name of service template to use
host_name                       localhost
service_description             PING
check_command                   check_ping!100.0,20%!500.0,60%
}

# Define a service to check the disk space of the root partition
# on the local machine.  Warning if < 20% free, critical if
# < 10% free space on partition.

define service{
use                             local-service         ; Name of service template to use
host_name                       localhost
service_description             Root Partition
check_command                   check_local_disk!20%!10%!/
}

# Define a service to check the number of currently logged in
# users on the local machine.  Warning if > 20 users, critical
# if > 50 users.

define service{
use                             local-service         ; Name of service template to use
host_name                       localhost
service_description             Current Users
check_command                   check_local_users!20!50
}

# Define a service to check the number of currently running procs
# on the local machine.  Warning if > 250 processes, critical if
# > 400 users.

define service{
use                             local-service         ; Name of service template to use
host_name                       localhost
service_description             Total Processes
check_command                   check_local_procs!250!400!RSZDT
}

# Define a service to check the load on the local machine.

define service{
use                             local-service         ; Name of service template to use
host_name                       localhost
service_description             Current Load
check_command                   check_local_load!5.0,4.0,3.0!10.0,6.0,4.0
}

>>> I. Mise en place du daemon Nagios

Pré-requis
Un serveur web Apache + PHP

Télécharger le package nagios (le plus recent)
> http://www.nagios.org/download
$ wget -O /tmp/nagios-3.0.1.tar.gz http://downloads.sourceforge.net/nagios/nagios-3.0.1.tar.gz

Se connecter sur le serveur cible (avec root)

# décompresser l’archive
$ tar zxvf nagios-x.y.tar.gz

# Création du groupe et user Nagios
$ groupadd nagios -g 600 (si vous souhaitez définir un gid precis)
$ groupadd nagcmd -g 601 (ce groupe servira pour les users qui font tourner Apache et Nagios)
$ useradd nagios -u 600 -g Nagios (le user nagios aura le uid 600 et pour groupe principal nagios)
$ /usr/sbin/usermod -G nagcmd apache (ajoute le user apache au groupe nagcmd)
$ /usr/sbin/usermod -G nagcmd nagios (ajoute le user nagios au groupe nagcmd)

# Vérification
$ id nagios
> uid=600(nagios) gid=600(nagios) groups=600(nagios),601(nagcmd)

# Création de l’environnement
$ mkdir /usr/local/nagios
$ chown nagios.nagios /usr/local/nagios

# Configuration pour compiler nagios
./configure –prefix=prefix                    (par défaut /usr/local/nagios)
–with-cgiurl=cgiurl            (par default /nagios/cgi-bin)
–with-htmurl=htmurl            (par defaut /nagios)
–with-nagios-user=someuser        (par defaut nagios)
–with-nagios-group=somegroup    (par defaut nagios)
–with-command-group=cmdgroup    (par defaut nagios)

exemple:
./configure –prefix=/usr/local/nagios
–with-cgiurl=/usr/local/nagios/cgi-bin
–with-htmurl=/usr/local/nagios/share
–with-nagios-user=nagios
–with-nagios-group=nagios
–with-command-group=nagcmd

# Compilation, installation
$ make all
$ make install

# Mise en place script init
$ make install-init

# Description du repertoire Nagios suite à l’installation

Sub-Directory     Contents
bin/             executables Nagios
etc/             Fichiers de configuration: Main, resource, object, CGI
sbin/             CGIs
share/             Fichiers HTML (Interface web et fichiers d’aide)
var/             Repertoire pour les fichiers logs, les statuts, etc…
var/archives     Repertoire pour les archives
var/rw             Repertoire pour le fichier de commande externe

# Installation des plugins

$ wget -O plugins-nagios.tar.gz http://downloads.sourceforge.net/nagios/ndoutils-1.4b7.tar.gz
> decompresser le fichier et placer tous les shells/binaires dans libexec. L’ensemble de ces plugins permettront de realiser les checks et de superviser ce qui doit l’etre.
Installing The Plugins

>>> II. Configuration de la partie Web

# Configuration du serveur Web Apache

> editer le httpd.conf

# Supplemental configuration
#
# The configuration files in the conf/extra/ directory can be
# included to add extra features or to modify the default configuration of
# the server, or you may simply copy their contents here and change as
# necessary.

# Nagios Config
Include conf/nagios.conf

# Server-pool management (MPM specific)
#Include conf/extra/httpd-mpm.conf

# Multi-language error messages
#Include conf/extra/httpd-multilang-errordoc.conf

> dans le reperoire de configuration de apache conf/, créer le fichier nagios.conf

ScriptAlias /nagios/cgi-bin /usr/local/nagios/sbin

<Directory “/usr/local/nagios/sbin”>
Options ExecCGI
AllowOverride None
Order allow,deny
Allow from all
AuthName “Nagios Access”
AuthType Basic
AuthUserFile /usr/local/nagios/etc/htpasswd.users
Require valid-user
</Directory>

Alias /nagios /usr/local/nagios/share

<Directory “/usr/local/nagios/share”>
Options None
AllowOverride None
Order allow,deny
Allow from all
AuthName “Nagios Access”
AuthType Basic
AuthUserFile /usr/local/nagios/etc/htpasswd.users
Require valid-user
</Directory>

<Directory “/usr/local/nagios/var”>
Options None
AllowOverride None
Order allow,deny
Allow from all
AuthName “Nagios Access”
AuthType Basic
AuthUserFile /usr/local/nagios/etc/htpasswd.users
Require valid-user
</Directory>

# Definition des users

Les commandes suivantes vont permettre de créer les users qui auront acces au site virtuel Nagios defini ci dessus.

# Creation du fichier htpasswd.users pour acces a Nagios
$ htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
$ htpasswd /usr/local/nagios/etc/htpasswd.users technicien

# editer le fichier cgi.cfg dans le repertoire etc/ de nagios
use_authentication=1

Par défaut la configuration vous suffira pour debuter, par la suite, je vous conseille de lire plus en detail les informations relatives aux CGIs, qui vous seront certainnemenbt utiles.

# relancer Apache
$ /etc/init.d/httpd restart

# Verification
> http://servername/nagios/

Nagios est maintenant installé et fonctionne correctement.
Il n’y a pour le moment rien de configuer pour son utilisation: superviser des serveurs et des services. Ce point fera l’objet d’un nouveau post (tres bientot)

A short post to update my CV link, which was refreshed because i’m back in north of France in Lille.
Please, read my CV and feel free to contact me.

When everything is ok, you should do like that:

startup
STARTUP OPEN PFILE=%ORACLE_BASE%\admin\nuxoradb\pfile\init.ora

shutdown
CONNECT system/manager@nuxoradb AS SYSDBA
SHUTDOWN NORMAL

The OPEN option starts the instance, reads the control file, attaches the database, and then opens it.
The OPEN option is the default option, it is not mandatory to write it.

The NORMAL option will wait for users to log out and then it will close the database and shutdown the instance.

Oracle logs, such as alert log file are very useful and give a good status about the databse and can explain many things, and help you to choose between different options.

Depending your needs, the situation you are facing, many options are available to start a database:

startup MOUNT
CONNECT system/manager@nuxoradb AS SYSDBA
STARTUP MOUNT PFILE=%ORACLE_BASE%\admin\nuxoradb\pfile\init.ora

The MOUNT option, starts the instance, reads the control file, and attaches the database, but does not open it.

To open and use the database:

ALTER DATABASE OPEN;

You have to do that because MOUNT option does’nt open your database

startup NOMOUNT
CONNECT system/manager@nuxoradb AS SYSDBA
STARTUP NOMOUNT PFILE=%ORACLE_BASE%\admin\nuxoradb\pfile\init.ora

The NOMOUNT option starts the instance without mounting the database. It means that only the memory structure and background processes are set up.

To open and use the database, you’ll have then to MOUNT it and OPEN it:

ALTER DATABASE MOUNT;
ALTER DATABASE OPEN;

startup READONLY
CONNECT system/manager@nuxoradb AS SYSDBA
STARTUP OPEN READ ONLY PFILE=%ORACLE_BASE%\admin\nuxoradb\pfile\init.ora

In the READ ONLY mode, You can only read, and no modification is possible, insert, update, or delete, create, later or drop are impossible to use.

And off course many options to shutdown oracle:

shutdown IMMEDIATE
CONNECT system/manager@nuxoradb AS SYSDBA
SHUTDOWN IMMEDIATE

The IMMEDIATE option won’t wait a user’s logoff either uncommitted rollback, it will shutdown the instance and close the database immediatly.

shutdown TRANSACTIONAL
SHUTDOWN TRANSACTIONAL
CONNECT system/manager@nuxoradb AS SYSDBA

The TRANSACTIONAL option tells oracle not to wait for a user to log off, but wait for the client to end the transaction that is in progress, then shut down the instance and close the database.

shutdown ABORT
CONNECT system/manager@nuxoradb AS sysdba
SHUTDOWN ABORT

The ABORT option shutdown the instance (no roll back, user sessions are killed).

And then you have a special option, in case of emergency:

shutdown ans startup FORCE
CONNECT system/manager@nuxoradb AS sysdba
STARTUP FORCE PFILE=%ORACLE_BASE%\admin\nuxoradb\pfile\init.ora

Je vous souhaite une bonne et heureuse année 2008, santé bonheur et réussite.

Le site a été en pause pendant deux mois, comme mes autres sites d’ailleurs. J’espere reprendre un meilleure rythme et bien rester axé sur Linux et Oracle avec des nouveaux posts dédiés à RAC.

L’autre news de ce post est la mise à jour du cv

A tres bientot

All is said in the post title, Oracle has launched a wiki.

This official public oracle wiki will permit to share content, information dealing with oracle technologies, with a very collaboratively tool, just try it [Oracle's WiKi]

La derniere version de Fedora est sortie le 8 novembre. Originalité de cette version, en plus de la version “full” traditionnelle, elle se présente sous trois angles différents:

- Fedora Games Spin : un Live DVD rempli de jeux 2D et 3D (Nexuiz, Quake, Freeciv, Nethack …)
- Fedora Developer Spin : un Live DVD qui contient seulement des programmes de développement (Eclipse, Anjuta, git, cvs, lynx, emacs, éditeur hexadécimal … )
- Fedora Electronics Lab : cette version est destinée aux personnes qui souhaitent utiliser des programmes de simulation de systèmes électroniques

La petite particularite qui m’interesse personnellement et l’amalioration de la prise en charge du wifi. NetworkManager 0.7 a été réécrit pour gagner en stabilité et en flexibilité. Celui-ci devrait assurer une plus grande rapidité de connexion, une meilleure intégration grâce à l’API Dbus et au WPA pour le wifi. (il était temps)

If you’d like to log the result from a sql script, just prepare your sql script like that:spool result.log
SET SERVEROUTPUT ON
select * from dual;
spool off
exit

Then from a command line or a script shell execute the following command:
# sqlplus user/pwd@db_name @script.sql