Redis Database

Pack Assets

Monitored Objects

The Pack Redis collects metrics for:

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

Collected Metrics

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

Prerequisites

To control your Redis database, the poller can execute INFO command (Eg: https://redis.io/commands/INFO)

Setup

Online License

1. Install the Centreon Plugin on every Poller:

yum install centreon-plugin-Applications-Databases-Redis

2. On the Centreon Web interface in Configuration > Plugin packs > Manager, install the Redis Database Pack

Offline License

1. Install the Centreon Plugin on every Poller:

yum install centreon-plugin-Applications-Databases-Redis

2. On the Centreon Central server, install the Pack from the RPM:

yum install centreon-pack-applications-databases-redis

3. On the Centreon Web interface in Configuration > Plugin packs > Manager, install the Redis Database Pack

Host configuration

• Add a new Host and apply the App-DB-Redis-custom Host Template

Once the template applied, some Macros have to be configured.

cli

With that configuration, the Plugin uses redis-cli executable. tls is supported (redis-cli >= 6.x mandatory).

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)

With that configuration, the Plugin uses Perl Redis module (eg: https://metacpan.org/pod/Redis). tls is unsupported.

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

How to install redis-cli 6.x ?

To use tls and/or ACL users, you need redis-cli >= 6.x.

Centos 7

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

How to test the Plugin and what are the main options for?

Once the plugin installed, log into your Centreon Poller CLI using the centreon-engine user account and test the Plugin by running the following command:

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

Expected command output is shown below:

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

The command above monitors client connections (--mode=clients).

It connects to the host 10.30.2.79 (--hostname='10.30.2.79') on the port 6379 (--port='6379').

All the options as well as all the available thresholds can be displayed by adding the --help parameter to the command:

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

Troubleshooting

Troubleshooting plugins