Major - P3 Attempting to start a sharded transaction on server version 4.1.5 with readConcern level "local" results in the following error:
"The first command in a transaction cannot specify a readConcern level other than snapshot or majority"
MongoDB Enterprise mongos> session = db.getMongo().startSession()
session { "id" : UUID("598f8543-7697-4822-bf6d-7f78b82cd00e") }
MongoDB Enterprise mongos> session.startTransaction({readConcern:{level:"local"}})
MongoDB Enterprise mongos> session.getDatabase("test").test.insert({})
WriteCommandError({
"ok" : 0,
"errmsg" : "The first command in a transaction cannot specify a readConcern level other than snapshot or majority",
"code" : 72,
"codeName" : "InvalidOptions",
"operationTime" : Timestamp(1542158775, 2),
"$clusterTime" : {
"clusterTime" : Timestamp(1542158775, 2),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
}
})
I thought the server was free to upgrade a user's readConcern from a lower level to a higher level. Are we going to support this in 4.2 or will mongos always reject "local"?