AWS Logging in Non-Blocking Mode: Handling Buffer Limitations and Throughput Concerns

In my experience using the awslog driver for log collection on Amazon Web Services (AWS), I encountered an issue where logs were not gathering correctly under non-blocking mode, particularly when encountering buffer size limitations. Here’s a detailed look at what happened and potential solutions:

Problem Encountered

While utilizing awslog with the following configurations – non-blocking as my logging driver choice and setting maximum payload sizes up to 25 MB, I noticed that log throughput was not exceeding this limit. This observation led me into deeper investigation: whenever a request’s data size surpassed approximately an additional quarter of a megabyte beyond the buffer threshold (0.25MB), some logs would simply vanish without being captured by AWS Logging service.

The complexity arises from having five log statements within my codebase—labelled as args, "built request", "got response" and "successfully got available hotels". The payload size for the third statement, “got response”, can occasionally exceed 1 MB; however this usually occurs when payloads are smaller than or equal to half a megabyte.

Understanding AWS Logging Constraints

Upon further research into Amazon Web Services documentation and related GitHub issues (specifically referring Github Issue #45999), I learned about the inherent limitations of log event sizes imposed by AWS CloudWatch Logs:

Amazon Web Services Limits for awslog
Log events must not exceed 256 KB (maximum). This quota is determined and cannot be adjusted, as per this guide. Understanding these boundaries has been pivotal in assessing the challenges faced with non-blocking mode logging where buffer size restrictions may cause incomplete log events to dissipate into oblivion without proper collection and analysis.

Next Steps for Resolution:

Based on this information, a few approaches can be considered moving forward:

1. Buffer Upgrades - While it’s noted that the 256 KB log event size limit cannot be modified per AWS documentation, exploring ways to optimize data processing within your application may prevent logs from reaching critical buffer sizes before transmission is complete could help manage overflow situations more gracefully and avoid loss.

2. Alternative Logging Solutions - Investigating alternative logging systems that provide greater control over log event sizing or different collection methodologies might be beneficial if you frequently deal with large payloads exceeding AWS’s imposed limit in non-blocked mode scenarios.

3. Monitor and Adjust Application Logic – Keep a vigilant eye on your application’s logging mechanisms to ensure that the size of log events remains within manageable ranges before sending them out, especially just under or below AWS’ limitation thresholds for optimal data capture without overflow issues in non-blocking mode.

The complexities around buffer limitations and throughput control when using awslog with a strict maximum payload capacity remind us of the importance to align technical solutions closely with service constraints. Further exploration into alternatives or adjustments may ensure reliable logging practices that accommodate your application’s needs effectively within AWS environment parameters.