Azure Cache for Redis monitoring and troubleshooting FAQs

You can monitor Azure Cache for Redis cache metrics in the Azure portal. You can pin metrics charts to your Dashboard, customize the date and time range of monitoring charts, add and remove metrics from the charts, and set alerts for certain conditions. For more information, see Monitor Azure Cache for Redis.

The following items in the left navigation menu for your cache also help you monitor and troubleshoot your cache.

• Diagnose and solve problems provides information about common issues and strategies for resolving them.
• Resource health under Help tells you if your resource is running as expected. For more information, see Resource health overview.
• Support + Troubleshooting under Help provides support options for your cache.

These tools help you monitor the health of your Azure Redis cache instances, and also help you manage your cached applications.

Timeouts can happen during client communication with Redis. When a client sends a command to the Redis server, the command is queued. The Redis server eventually picks up the command and executes it. The client request can time out during this process, and an exception is raised on the calling side.

For more information on troubleshooting timeout issues, see Troubleshoot Azure Cache for Redis latency and timeouts and Investigating timeout exceptions in StackExchange.Redis for Azure Redis Cache.

The following are some common reasons for a cache disconnect.

Client-side

• The client application was redeployed.
• The client application did a scaling operation. Cloud Services or Web Apps might cause a cache disconnect during autoscaling.
• The networking layer on the client side changed.
• Transient errors occurred in the client or in the network nodes between the client and the server.
• The bandwidth threshold limits were reached.
• CPU-bound operations took too long to complete.

Server-side

• A Standard-tier cache started a failover from the primary node to the replica node.
• Azure was patching the cache instance during a Redis server update or general virtual machine (VM) maintenance.

The error message Cache is busy processing a previous update request or is undergoing system maintenance. As such, it's currently unable to accept the update request. Try again later. indicates that a management operation, like scaling or patching, is in progress on your cache. All other management operations are blocked until the ongoing operation completes.

The ongoing management operation usually completes in a few hours. If you see this error for more than 12 hours, contact Azure support. During this time, your Azure Redis cache is fully functional for client operations.

An Azure Redis cache can show a Failed state if a management operation fails. Despite this state, your Azure Redis cache is fully functional for client operations.

Zone information might be missing from your subscription for the following reasons:

• Your subscription might not be registered with the Microsoft.Cache provider. Sign in to your subscription and run the following PowerShell command: Register-AzureRmResourceProvider -ProviderNamespace Microsoft.Cache.
• Your subscription might not be enabled for zones. Contact Azure support so they can enable your subscription for zones. Then reregister the Microsoft.Cache provider even if you already registered it for your subscription.

Related content

• How to monitor Azure Cache for Redis
• Planning FAQs
• Development FAQs
• Management FAQs
• Azure Redis Cache FAQs