Release Notes for MongoDB 8.3

findShardsOnConfigTimeoutMS Parameter

MongoDB 8.3 adds the findShardsOnConfigTimeoutMS parameter which sets the timeout in milliseconds for find operations against the config.shards namespace. For details, see findShardsOnConfigTimeoutMS.

config.csrs.indexes Removed

MongoDB 8.3 removes the config.csrs.indexes namespace.

Time Series

Starting in MongoDB 8.3, creating an index with the name of "_id_" or specifying a hint of "_id_" on time series collections returns an error.

Fields to Track Use of Memory by Queries

Starting in MongoDB 8.3, you can use the following new fields to track query memory use:

Both fields appear in the following places:

• $currentOp (aggregation stage) output

• db.currentOp() output

• Database profiler output

• Log messages

• Slow query log messages

The peakTrackedMemBytes field also appears in the following places:

• Explain results

• PlanCache.list() output

• $planCacheStats output