Azure Cache for Redis

Overview

Azure Cache for Redis provides an in-memory data store based on the Redis software. Redis improves the performance and scalability of an application that uses backend data stores heavily. It's able to process large volumes of application requests by keeping frequently accessed data in the server memory, which can be written to and read from quickly. Redis brings a critical low-latency and high-throughput data storage solution to modern applications.

The Centreon Plugin Pack Azure Cache for Redis can rely on Azure API or Azure CLI to collect the metrics related to the Redis service.

Pack Assets

Monitored Objects

• Azure Cache for Redis instances
  • Cache-Latency
  • Cache-Throughput
  • Cache-Usage
  • Clients
  • Cpu
  • Discovery
  • Errors
  • Health
  • Load
  • Memory
  • Operations

Discovery rules

The Centreon Plugin Pack Azure Cache for Redis includes a Host Discovery provider to automatically discover the Azure instances of a given subscription and add them to the Centreon configuration. This provider is named Microsoft Azure Cache for Redis:

This discovery feature is only compatible with the 'api' custom mode. 'azcli' is not supported.

More information about the Host Discovery module is available in the Centreon documentation: Host Discovery

Collected metrics & status

Cache-Latency

Metric Name	Description	Unit
redis.cache.latency.microseconds	Cache Latency	μs

Cache-Throughput

Metric Name	Description	Unit
redis.cache.read.throughput.bytespersecond	Cache Read Throughput	B/s
redis.cache.write.throughput.bytespersecond	Cache Write Throughput	B/s

Cache-Usage

Metric Name	Description	Unit
redis.cache.hits.count	Cache Hits	Count
redis.cache.misses.count	Cache Misses	Count

Clients

Metric Name	Description	Unit
redis.cache.clients.connected.count	Connected Clients	Count

Cpu

Metric Name	Description	Unit
redis.cache.cpu.usage.percentage	CPU Usage Percentage	%

Errors

Metric Name	Description	Unit
redis.cache.errors.count	Errors	Count

Health

Status Name	Description
status	Current operational status
summary	Last related status message

Load

Metric Name	Description	Unit
redis.cache.server.load.percentage	Server Load	%

Memory

Metric Name	Description	Unit
redis.cache.memory.usage.percentage	Memory Usage Percentage	%

Operations

Metric Name	Description	Unit
redis.cache.operations.persecond	Operations per seconds	op/s

Prerequisites

Please find all the prerequisites needed for Centreon to get information from Azure in the dedicated page.

Setup

Online License

1. Install the Centreon Plugin package on every Centreon poller expected to monitor Azure Cache for Redis resources:

yum install centreon-plugin-Cloud-Azure-Database-Redis-Api

2. On the Centreon Web interface, install the Azure Cache for Redis Centreon Plugin Pack on the "Configuration > Plugin Packs > Manager" page

Offline License

1. Install the Centreon Plugin package on every Centreon poller expected to monitor Azure Cache for Redis resources:

yum install centreon-plugin-Cloud-Azure-Database-Redis-Api

2. Install the Centreon Plugin Pack RPM on the Centreon Central server:

yum install centreon-pack-cloud-azure-database-redis.noarch

3. On the Centreon Web interface, install the Azure Cache for Redis Centreon Plugin Pack on the "Configuration > Plugin Packs > Manager" page

Configuration

Host

• Log into Centreon and add a new Host through "Configuration > Hosts".

• In the IP Address/FQDN field, set the following IP address: '127.0.0.1'.

• Select the Cloud-Azure-Database-Redis-custom template to apply to the Host.

• Once the template applied, some Macros marked as 'Mandatory' hereafter have to be configured. These mandatory Macros differ regarding the custom mode used.

Two methods can be used to set the Macros:

• full ID of the Resource (/subscriptions/<subscription_id>/resourceGroups/<resourcegroup_id>/providers/Microsoft.Network/<resource_type>/<resource_name>) in AZURERESOURCE
• Resource Name in AZURERESOURCE associated with Resource Group (in AZURERESOURCEGROUP) and Resource Type (in AZURERESOURCETYPE)

Azure Monitor API

Mandatory	Nom	Description
X	AZURECUSTOMMODE	Custom mode 'api'
X	AZURESUBSCRIPTION	Subscription ID
X	AZURETENANT	Tenant ID
X	AZURECLIENTID	Client ID
X	AZURECLIENTSECRET	Client secret
X	AZURERESOURCE	ID or name of the Redis resource
	AZURERESOURCEGROUP	Associated Resource Group if resource name is used
X	AZURERESOURCETYPE	Associated Resource Type if resource name is used

Azure AZ CLI

Mandatory	Nom	Description
X	AZURECUSTOMMODE	Custom mode 'azcli'
X	AZURESUBSCRIPTION	Subscription ID
X	AZURERESOURCE	ID or name of the Redis resource
X	AZURERESOURCEGROUP	Associated Resource Group if resource name is used
X	AZURERESOURCETYPE	Associated Resource Type if resource name is used

How to check in the CLI that the configuration is OK 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_azure_database_redis_api.pl \
    --plugin=cloud::azure::database::redis::plugin \
    --mode=cache-latency \
    --custommode=api \
    --subscription='xxxxxxxxx' \
    --tenant='xxxxxxxxx' \
    --client-id='xxxxxxxxx' \
    --client-secret='xxxxxxxxx' \
    --resource='REDIS001ABCD' \
    --resource-group='RSG1234' \
    --timeframe='900' \
    --interval='PT5M' \
    --aggregation='Average' \
    --warning-cache-latency='8000' \
    --critical-cache-latency='9000'

Expected command output is shown below:

OK: Instance 'REDIS001ABCD' Statistic 'average' Metrics Cache Latency: 1206.15μs | 'REDIS001ABCD~average#redis.cache.latency.microseconds'=1206.15μs;;;0;

The command above checks the Cache Latency time of an Azure Azure Cache for Redis instance using the 'api' custom-mode (--plugin=cloud::azure::database::redis::plugin --mode=cache-latency --custommode=api). This instance is identified by its id (--resource='REDIS001ABCD') and its associated group (--resource-group='RSG1234'). The authentication parameters to be used with the custom mode are specified in the options (--subscription='xxxxxxxxx' --tenant='xxxxxxx' --client-id='xxxxxxxx' --client-secret='xxxxxxxxxx').

The calculated metrics are the average values (--aggregation='Average') of a 900 secondes / 15 min period (--timeframe='900') with one sample per 5 minutes (--interval='PT5M').

This command would trigger a WARNING alarm if the Cache Latency time is reported as over 8000µs (--warning-cache-latency='8000') and a CRITICAL alarm over 9000µs (--critical-cache-latency='8000').

All the available options for a given mode can be displayed by adding the --help parameter to the command:

/usr/lib/centreon/plugins/centreon_azure_database_redis_api.pl \
    --plugin=cloud::azure::database::redis::plugin \
    --mode=cache-latency \
    --help

Troubleshooting

The Azure credentials have changed and the Plugin does not work anymore

The Plugin is using a cache file to keep connection information and avoid an authentication at each call. If some of the authentication parameters change, you must delete the cache file.

The cache file can be found within /var/lib/centreon/centplugins/ folder with a name similar to azureapi<md5>_<md5>_<md5>_<md5>.

UNKNOWN: Login endpoint API returns error code 'ERROR_NAME' (add --debug option for detailed message)

It means that some parameters used to authenticate the API request are wrong. The 'ERROR_NAME' string gives some hints about where the problem stands.

As an example, if my Client ID or Client Secret are wrong, 'ERROR_DESC' value will be 'invalid_client'.

UNKNOWN: 500 Can't connect to login.microsoftonline.com:443

This error message means that the Centreon Plugin couldn't successfully connect to the Azure Login API. Check that no third party device (such as a firewall) is blocking the request. A proxy connection may also be necessary to connect to the API. This can be done by using this option in the command: --proxyurl='http://proxy.mycompany:8080'.

UNKNOWN: No metrics. Check your options or use --zeroed option to set 0 on undefined values

This command result means that Azure does not have any value for the requested period. This result can be overriden by adding the --zeroed option in the command. This will force a value of 0 when no metric has been collected and will prevent the UNKNOWN error message.