mongodb 杀掉索引进程

在MongoDB上建索引可能会对MongoDB集群对可用性产生负面影响。在生产服务上，如果针对一个大集合触发建立索引，且在前台运行，你可能会发现，在索引建完之前，整个集群都无响应。在一个大集合上，这个过程可能会持续几个小时，甚至几天。一旦你触发一个索引，简单的重启服务并不能解决这个问题，因为MongoDB会继续重启前的建索引的工作。如果之前你运行后台建索引任务，在服务重启后它会变成前台运行的任务。在这种情况下，重启会让问题变得更糟糕。

解决办法：使用db.currentOp()定位建索引进程，然后使用db.killOp(<opid>)杀掉进程：

db.currentOp();

{
            "host" : "server-053.localdomain:27017", 
            "desc" : "conn", 
            "threadId" : "140264163313408", 
            "connectionId" : 946.0, 
            "client" : "192.168.1.93:49372", 
            "clientMetadata" : {
                "driver" : {
                    "name" : "mongo-java-driver", 
                    "version" : "3T_5.1.1-478-gfd17fbf"
                }, 
                "os" : {
                    "type" : "Windows", 
                    "name" : "Windows 7", 
                    "architecture" : "amd64", 
                    "version" : "6.1"
                }, 
                "platform" : "Java/Oracle Corporation/1.8.0_131-b11"
            }, 
            "active" : true, 
            "currentOpTime" : "2018-05-28T09:52:40.567+0800", 
            "opid" : 1420164.0, 
            "secs_running" : NumberLong(679), 
            "microsecs_running" : NumberLong(679091899), 
            "op" : "command", 
            "ns" : "data_test.$cmd", 
            "command" : {
                "createIndexes" : "achievement", 
                "indexes" : [
                    {
                        "key" : {
                            "record.documents.0.docTitle" : 1.0
                        }, 
                        "name" : "record.documents.0.docTitle_1", 
                        "ns" : "data_test.achievement"
                    }
                ], 
                "$db" : "data_test"
            }, 
            "msg" : "Index Build Index Build: 469019/78412152 0%", 
            "progress" : {
                "done" : 469019.0, 
                "total" : 78412152.0
            }, 
            "numYields" : 0.0, 
            "locks" : {
                "Global" : "w", 
                "Database" : "W", 
                "Collection" : "w"
            }, 
            "waitingForLock" : false, 
            "lockStats" : {
                "Global" : {
                    "acquireCount" : {
                        "r" : NumberLong(1), 
                        "w" : NumberLong(1)
                    }
                }, 
                "Database" : {
                    "acquireCount" : {
                        "W" : NumberLong(1)
                    }, 
                    "acquireWaitCount" : {
                        "W" : NumberLong(1)
                    }, 
                    "timeAcquiringMicros" : {
                        "W" : NumberLong(1336357)
                    }
                }, 
                "Collection" : {
                    "acquireCount" : {
                        "w" : NumberLong(1)
                    }
                }
            }
        }

db.killOp(1420164);

让索引在后台创建，添加{background:true}参数：

db.works.createIndex({a:1,b:1},{background:true})