mongodb - mongdb index does not work properly -

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environment

10.10.109.131:23000   =>   shard000 10.10.109.131:23001   =>   shard001 10.10.111.251:23000   =>   shard000 10.10.111.251:23001   =>   shard001 10.10.97.197:23000    =>   shard000 10.10.97.197:23001    =>   shard001

phenomenon

view abnormally high in system.profile table scan, explain query again found table scan return normal

issue sql:

db.followers.find({"$and":[{"$or":[{"vaild":0},{"vaild":null}]},{"from":{"$in":[576893,2095602,1184292,650082,1373126,875232,815151,556585,1391458,813307,600211,2273636,106322,2206656,804217]}},{"to":1600312},{"$or":[{"vaild":null},{"vaild":0}]}]})

system.profile

      "op" : "query",       "ns" : "chuyesocial.followers",       "query" : {         ...       },       "ntoreturn" : 0,       "ntoskip" : 0,       "nscanned" : 424277,       "nscannedobjects" : 424263,

explain

shard001:primary> db.followers.find({"$and":[{"$or":[{"vaild":0},{"vaild":null}]},{"from":{"$in":[576893,2095602,1184292,650082,1373126,875232,815151,556585,1391458,813307,600211,2273636,106322,2206656,804217]}},{"to":1600312},{"$or":[{"vaild":null},{"vaild":0}]}]}).explain() {     "queryplanner" : {         "plannerversion" : 1,         "namespace" : "chuyesocial.followers",         "indexfilterset" : false,         "parsedquery" : {             ...         },     "executionstats" : {         "executionsuccess" : true,         "nreturned" : 13,         "executiontimemillis" : 4,         "totalkeysexamined" : 17,         "totaldocsexamined" : 17,         "executionstages" : {             "stage" : "keep_mutations",             "nreturned" : 13,             "executiontimemillisestimate" : 0,             "works" : 20,             "advanced" : 13,             "needtime" : 4,             "needfetch" : 1,             "savestate" : 5,             "restorestate" : 5,             "iseof" : 1,             "invalidates" : 0,              }         } }

index information

"_id_" : 37486960, "from_1__id_1" : 69896624,  （sharedkey） "to_1" : 37560544

other ：there 2 machines in cluster cpu 100% of cases


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