• Adds a new 'metadata' flag to the 'validate' command which only performs validation on the collection metadata. This is to allow users to perform a quick validation to detect invalid index options without scanning all of the documents and indexes.
• 'validate' detects invalid index options and recommends running 'collMod' to remove the invalid index options.

Sample log messages:
2021-09-24T14:43:20.964+00:00 I COMMAND 20514 [conn1] "CMD: validate","attr":

2021-09-24T14:43:20.964+00:00 I STORAGE 5980501 [conn1] "Validation of metadata complete for collection. Problems detected","attr":{"namespace":"test.validate_detects_invalid_index_options","uuid":{"uuid":

}}

• The 'collMod' command can be used to remove the invalid index options for all indexes on the given collection.

Can be executed through:
db.runCommand(

)

Sample log messages:
2021-09-24T14:43:22.309+00:00 I COMMAND 5324200 [conn1] "CMD: collMod","attr":{"cmdObj":{"collMod":"collmod_removes_invalid_index_options"}}
2021-09-24T14:43:22.309+00:00 W INDEX 23878 [conn1] "Removing unknown field from index spec","attr":{"fieldName":"safe","indexSpec":{"v":2,"key":

,"name":"x_1","safe":true,"sparse":true,"force":false}}
2021-09-24T14:43:22.309+00:00 W INDEX 23878 [conn1] "Removing unknown field from index spec","attr":{"fieldName":"force","indexSpec":{"v":2,"key":

,"name":"x_1","safe":true,"sparse":true,"force":false}}
2021-09-24T14:43:22.309+00:00 W INDEX 23878 [conn1] "Removing unknown field from index spec","attr":{"fieldName":"xyz","indexSpec":{"v":2,"key":

,"name":"z_1","xyz":false}}