Mongodb db.serverStatus()所關心的幾個輸出值

1. globalLock，關鍵是看一下PRIMARY節點上的參數

"globalLock" : {
                                 "totalTime" : 47279680356,
                                 "lockTime" : 1586763,
                                 "ratio" : 0.00003356120405324679,
                                 "currentQueue" : {
                                                 "total" : 0,
                                                 "readers" : 0,
                                                 "writers" : 0
                                },
                                 "activeClients" : {
                                                 "total" : 2,
                                                 "readers" : 2,
                                                 "writers" : 0
                                }
                },

activeClients表示中能夠看出slave有兩個，這個值在slave上始終爲0
2. connections客戶端鏈接數
Master上的

"connections" : {
         "current" : 9,
         "available" : 810
},

Slave上的

"connections" : {
     "current" : 16,
     "available" : 803
},

在客戶端增長讀取線程後，Master上不會變，而Slave上會增長

3. opcounters
Master上

"opcounters" : {
         "insert" : 7,
         "query" : 1215,
         "update" : 33,
         "delete" : 1,
         "getmore" : 32558,
         "command" : 48141
},

Slave上

"opcounters" : {
             "insert" : 0,
             "query" : 4971,
             "update" : 0,
             "delete" : 0,
             "getmore" : 0,
             "command" : 44342 },

能夠看到insert、update、delete是在Master上，查詢是在slave上，能夠檢查master-slave設置是否正確，注意要先執行過rs.slaveOk()