1、i check replication info that i find the one secondary lag more than 9000s
shard4:SECONDARY> rs.printSlaveReplicationInfo()
source: mongodb68:31004
syncedTo: Tue Feb 14 2023 12:36:01 GMT+0800 (CST)
0 secs (0 hrs) behind the primary
source: mongodb69:31004
syncedTo: Tue Feb 14 2023 10:03:40 GMT+0800 (CST)
9141 secs (2.54 hrs) behind the primary
2、i check lock. serverStatus:1 is locked by "ParallelBatchWriterMode" : "r"

{
"type" : "op",
"desc" : "conn323699",
"connectionId" : 323699,
"clientMetadata" : {
"driver" :

{ "name" : "mongo-go-driver", "version" : "v1.0.1" }

,
"os" :

{ "type" : "linux", "architecture" : "amd64" }

,
"platform" : "go1.13.10"
},
"active" : true,
"currentOpTime" : "2023-02-14T10:43:50.888+08:00",

"opid" : -1523928877,
"secs_running" : NumberLong(2831),
"microsecs_running" : NumberLong("2831816411"),
"op" : "command",
"ns" : "admin.$cmd",
"command" : {
"serverStatus" : 1,
"advisoryHostFQDNs" : 1,
"locks" : 0,
"recordStats" : 0,
"oplog" : 0,
"$clusterTime" : {
"clusterTime" : Timestamp(1676339797, 2140),
"signature" :

{ "hash" : BinData(0,"/2uRF//p/2dkSYG0iauiyFybodI="), "keyId" : NumberLong("7143870411116118530") }

},
"$db" : "admin",
"$readPreference" :

{ "mode" : "primaryPreferred" }

},
"numYields" : 0,
"waitingForLatch" :

{ "timestamp" : ISODate("2023-02-14T02:43:50.876Z"), "captureName" : "CondVarLockGrantNotification::_mutex" }

,
"locks" :

{ "ParallelBatchWriterMode" : "r" }

,
"waitingForLock" : true,
"lockStats" : {
"ParallelBatchWriterMode" : {
"acquireCount" :

{ "r" : NumberLong(2) }

,
"acquireWaitCount" :

{ "r" : NumberLong(2) }

,
"timeAcquiringMicros" :

{ "r" : NumberLong("2831703688") }

}
},
"waitingForFlowControl" : false,
"flowControlStats" : {

}
},
{
"type" : "op",
"desc" : "OplogApplier-0",
"active" : true,
"currentOpTime" : "2023-02-14T11:20:14.842+08:00",
"effectiveUsers" : [

{ "user" : "__system", "db" : "local" }

],
"opid" : -1524195878,
"op" : "none",
"ns" : "",
"command" : {

},
"numYields" : 0,
"locks" :

{ "ParallelBatchWriterMode" : "W" }

,
"waitingForLock" : false,
"lockStats" : {
"ParallelBatchWriterMode" : {
"acquireCount" :

{ "W" : NumberLong(1) }

},
"ReplicationStateTransition" : {
"acquireCount" :

{ "w" : NumberLong(4) }

},
"Global" : {
"acquireCount" :

{ "r" : NumberLong(1), "w" : NumberLong(3) }

},
"Database" : {
"acquireCount" :

{ "r" : NumberLong(1), "w" : NumberLong(3) }

},
"Collection" : {
"acquireCount" :

{ "r" : NumberLong(1), "w" : NumberLong(3) }

},
"Mutex" : {
"acquireCount" :

{ "r" : NumberLong(4) }

}
},
"waitingForFlowControl" : false,
"flowControlStats" : {

}
}