Recommended go-redis ReadTimeout settings for PING to Memorystore Redis

[derekfrei]

I am using Memorystore Redis as the backend of an Go application that sends periodic healthchecks to Redis via PING requests (go-redis, v8.11.5). We have noticed sporadic failures across our deployments when we set the timeout on the PING to one second.

We have come across advice on online forums to recommends against using Go context timeouts for requests like this to avoid connection thrashing. This is step zero for us to fix this problem.

The next step is to configure a specific value for the go-redis ReadTimeout and WriteTimeout that represent a stable Memorystore instance. Is there a value that you would recommend for this? The default value for ReadTimeout in go-redis is 3 seconds.

[ms4446 · Accepted solution]

In Cloud Memorystore, selecting appropriate operation timeouts is pivotal. The default 3-second ReadTimeout in the go-redis library serves as a practical initial setting. Yet, optimal configurations must account for network latency, application load patterns, and the specific Redis instance's capacity and load.

Key Considerations:

• Network Latency: Cross-region deployments can significantly increase latency. Timeouts should reflect the physical distance between your application and the Memorystore instance.

• Load Patterns: Critical user-facing operations may require shorter timeouts to ensure quick failure detection and recovery.

• Redis Instance Capacity and Load: The performance characteristics of your Memorystore instance directly influence optimal timeout settings.

Recommendations:

1. Start with Default Settings: Use the 3-second ReadTimeout and WriteTimeout as initial benchmarks.

2. Engage in Comprehensive Monitoring: Utilize Cloud's monitoring tools to observe latency, error rates, and command-specific latencies. This data informs targeted adjustments.

3. Iterate with Precision: Adjust timeouts incrementally, based on monitoring insights, to find the balance that best suits your application's needs.

4. Employ Contextual Timeouts: Utilize Go's context timeouts for critical operations, allowing for more nuanced control over operation time limits.

5. Optimize Connection Pooling: A well-configured connection pool reduces latency and overhead, mitigating timeout-related issues.

6. Conduct Thorough Load Testing: Simulate real-world traffic patterns to validate the effectiveness of your timeout settings under various conditions.

Advanced Strategies:

• Adaptive Timeouts: Implement real-time adjustments to timeouts based on recent performance metrics, accommodating dynamic application and network conditions.

• Distributed Tracing: Leverage distributed tracing to assess the impact of Redis latencies on overall application performance, guiding fine-tuning efforts.

• Batch Operations and High Availability: Adjust timeouts for batch operations and high-availability scenarios to balance rapid failure detection with the avoidance of false positives.

Testing and Validation:

• Embrace Chaos Engineering: Test your application's resilience and timeout strategies under diverse failure scenarios to ensure robustness.

• Utilize Benchmarking Tools: Benchmark your Memorystore instance to establish realistic timeout settings based on its performance capabilities.

A strategic, data-informed approach to configuring Redis timeouts is essential for balancing performance and reliability in cloud environments. By starting with sensible defaults and refining settings based on empirical data and advanced strategies, you can ensure that your application remains responsive and stable, adapting smoothly to varying conditions and loads.