I'm trying to configure the threadpool of my Elasticsearch cluster. The fixed_auto_queue_size looks a neat idea as it adjusts its maximum queue size based on Little's Law. However, this feature is deprecated in ES 7.7.0. Does anyone know why the feature is deprecated? I'm interested in practical issues that this configuration will have. Is it because Little's Law assumes a stable system? If so, what could go wrong when the assumption is not true any more?

CodePudding user response：

When looking at the details of this change, the two given reasons were that:

• the two fixed_auto_queue_size thread pools (search and search_throttled) were not configuring this dynamic adjustment
• Elastic was not aware of any user making use of this dynamic setting

Since the feature was experimental and they didn't get much feedback on it, they decided to remove it.