hi

    we have a problem when we send query same litter data collections in secondary always appear same very slowly query problems ,every day about one or two times.in the slowly logs we could find the timeAcquiringMicros take the longest time in the query.i think if always appear this problem .maybe we can't use secondary as one of the query point for share the responsibility of primary .because this will block  the query too long time.and let our program became dead.maybe in this time the  ParallelBatchWriterMode is PBWM 

the log like this 

2019-10-12T07:34:50.684+0800 I COMMAND [conn1279777] command gacc.r_plugin command: find { find: "r_plugin", filter:

, limit: 1, shardVersion: [ Timestamp 0|0, ObjectId('000000000000000000000000') ] } planSummary: IXSCAN { type: 1 } keysExamined:1 docsExamined:1 cursorExhausted:1 numYields:0 nreturned:1 reslen:350 locks:{ Global: { acquireCount:

, acquireWaitCount: { r: 1 }, timeAcquiringMicros: { r: 38560627 } }, Database: { acquireCount:{ r: 1 }}, Collection: { acquireCount:{ r: 1 }} } protocol:op_command 38560ms