I have a simple question regarding the MongoDB wired-tiger engine cache, what is happening after the cache size in the memory reach to the max limit? is it release old cached data from the ram or the instance will stop?
and anyway to automatic release the old data in the cache?
I’m pretty sure the instance will NOT stop otherwise nobody will use the product. But cache eviction can be implemented in multiple ways (for instance, mysql uses double headed list ). You can try searching in wiredtiger doc
When an application approaches the maximum cache size, WiredTiger evicts content from the cache to keep it under the configured size, approximating a least-recently-used algorithm. The algorithm attempts to keep the most frequently accessed and most recently used data in the cache while removing the least frequently accessed and least recently used data.
WiredTiger provides several configuration options for tuning how pages are evicted from the cache. Please refer to the Cache and eviction tuning documentation for more details.
I hope it answers your question. Please feel free to ask if you have any further questions.