Redis Database

Contenu du Pack

Objets supervisés

Le Pack Redis collecte les données pour:

• Clients
• Commands
• Connections
• Cpu
• Memory
• Persistence
• Replication

Métriques collectées

Clients

Metric name	Description	Unit
clients.connected.count	Number of client connections (excluding replica connections)
clients.blocked.count	Number of clients pending on a blocking call
clients.longest_output_list.count	Longest output list among current client connections
clients.biggest_input_buffer.count	Biggest input buffer among current client connections

Commands

Metric name	Description	Unit
commands.processed.count	Total number of commands processed by the server
commands.processed.persecond	Number of commands processed per second

Connections

Metric name	Description	Unit
connections.received.count	Number of connections accepted by the server
connections.rejected.count	Number of connections rejected because of maxclients limit
network.traffic.in.bitspersecond	Incoming traffic going through from the network	b/s
network.traffic.out.bitspersecond	Outgoing traffic going through from the network	b/s

Cpu

Metric name	Description	Unit
cpu.system.usage.percentage	System CPU consumed by the Redis server	%
cpu.user.usage.percentage	User CPU consumed by the Redis server	%
cpu.system.children.usage.percentage	System CPU consumed by the background processes	%
cpu.user.children.usage.percentage	User CPU consumed by the background processes	%

Memory

Metric name	Description	Unit
memory.usage.bytes	Number of bytes allocated by Redis using its allocator	B
memory.rss.usage.bytes	Number of bytes that Redis allocated as seen by the operating system	B
memory.peak.usage.bytes	Peak memory consumed by Redis	B
memory.overhead.usage.bytes	The sum in bytes of all overheads that the server allocated for managing its internal data structures	B
memory.startup.usage.bytes	Initial amount of memory consumed by Redis at startup in bytes	B
memory.dataset.usage.bytes	The size in bytes of the dataset	B
memory.lua.usage.bytes	Number of bytes used by the Lua engine	B
memory.fragmentation.ratio.count	Ratio between used_memory_rss and used_memory
memory.defragmentation.running.count	Indicates whether defragmentation is currently active
memory.lazy_pending_objects.count	The number of objects waiting to be freed

Persistence

Metric name	Description	Unit
RDB status	Status of the last RDB save operation and if RDB save is on-going
rdb.changes.since_last_save.count	Number of changes since the last dump
rdb.last_successful_save.seconds	Time since last successful save	s
rdb.last_save.size.bytes	Size of copy-on-write memory during the last RDB save operation	B
rdb.last_save.duration.seconds	Duration of the last RDB save operation	s
rdb.current_save.duration.seconds	NDuration of the on-going RDB save operation	s

Replication

Metric name	Description	Unit
replication status	Status of the link with the master and if master is syncing
replication.slaves.connected.count	Number of connected replicas
replication.master.offset.count	The server's current replication offset
replication.master.last_interaction.seconds	Number of seconds since the last interaction with master	s
replication.slave.offset.count	The replication offset of the replica instance
replication.slave.priority.count	The priority of the instance as a candidate for failover
replication.slave.readonly.count	Flag indicating if the replica is read-only

Prérequis

Afin de contrôler votre base de données Redis, le collecteur doit pouvoir exécuter la commande INFO (cf: https://redis.io/commands/INFO).

Installation

Online License

1. Installer le Plugin sur tous les Collecteurs Centreon :

yum install centreon-plugin-Applications-Databases-Redis

2. Sur l'interface Web de Centreon, installer le Pack Redis Database depuis la page Configuration > Plugin Packs > Gestionnaire

Offline License

1. Installer le Plugin sur tous les Collecteurs Centreon :

yum install centreon-plugin-Applications-Databases-Redis

2. Sur le serveur Central Centreon, installer le Pack via le RPM:

yum install centreon-pack-applications-databases-redis

3. Sur l'interface Web de Centreon, installer le Pack Redis Database depuis la page Configuration > Plugin Packs > Gestionnaire

Configuration

Ce Pack est conçu de manière à avoir dans Centreon un hôte par base de données Redis. Lorsque vous ajoutez un hôte à Centreon, appliquez-lui le modèle App-DB-Redis-custom. Une fois celui-ci configuré, certaines macros doivent être renseignées.

cli

Avec cette configuration, le Plugin utilise l'exécutable redis-cli. tls est supporté à partir de la version 6.x.

Mandatory	Name	Description
X	REDISCUSTOMMODE	Name of the backend: cli
	REDISPORT	Port used (Default: 6379)
	REDISUSERNAME	Redis username (redis-cli >= 6.x mandatory)
	REDISPASSWORD	Redis password
	REDISSENTINEL	Sentinel server
	REDISSENTINELORT	Sentinel port (Default: 26379)
	REDISSERVICE	Service parameter (mandatory if REDISENTINEL macro used)
	REDISEXTRAOPTIONS	Any extra option you may want to add to the command (eg. a --tls --insecure)

perlmod (default)

Avec cette configuration, le Plugin utilise le module Perl Redis (cf: https://metacpan.org/pod/Redis). tls n'est pas supporté.

Mandatory	Name	Description
X	REDISCUSTOMMODE	Name of the backend: perlmod
	REDISPORT	Port used (Default: 6379)
	REDISPASSWORD	Redis password
	REDISSENTINEL	Sentinel server
	REDISSENTINELORT	Sentinel port (Default: 26379)
	REDISSERVICE	Service parameter (mandatory if REDISENTINEL macro used)
	REDISEXTRAOPTIONS	Any extra option you may want to add to the command

Comment installer redis-cli 6.x ?

Pour le support tls et des utilisateurs ACLs, une version 6.x minimum de redis-cli est nécessaire.

Centos 7

yum install epel-release
yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm 
yum --enablerepo=remi install redis

Comment puis-je tester le Plugin et que signifient les options des commandes ?

Une fois le Plugin installé, vous pouvez tester celui-ci directement en ligne de commande depuis un collecteur Centreon en vous connectant avec l'utilisateur centreon-engine:

/usr/lib/centreon/plugins/centreon_database_redis.pl \
    --plugin=database::redis::plugin \
    --custommode=perlmod \
    --mode=clients \
    --server='10.30.2.79' \
    --port='6379' \
    --verbose

La commande devrait retourner un message de sortie de la forme ci-dessous:

OK: Clients connected: 1, blocked: 0 | 'clients.connected.count'=1;;;0; 'clients.blocked.count'=0;;;0;

Cette commande contrôle les connexions clientes (--mode=clients).

La commande se connecte à l'hôte 10.30.2.79 (--hostname='10.30.2.79') sur le port 6379 (--port='6379').

Pour chaque mode, la liste de toutes les métriques, seuils associés et options complémentaires peuvent être affichés en ajoutant le paramètre --help à la commande:

/usr/lib/centreon/plugins/centreon_database_redis.pl \
    --plugin=database::redis::plugin \
    --custommode=perlmod \
    --mode=clients \
    --help

Diagnostique

Diagnostique des plugins