------------紅色字體的四個field個人認爲是重要參數，過高即可重啓db----------------
Fields
mongostat returns values that reflect the operations over a 1 second period. When mongostat <sleeptime> has a value greater than 1, mongostat averages the statistics to reflect average operations per second.
mongostat outputs the following fields:
- inserts
-
每秒鐘插入到數據庫中的對象數目。如果後面跟有一個星號（即 *），則該數據表示一個複製操作。
- query
-
每秒鐘的查詢操作數目。
- update
-
每秒鐘的更新操作數目。
- delete
-
每秒鐘的刪除操作數目。
- getmore
-
每秒鐘的獲取更多（如光標批次）操作數目。
- command
-
The number of commands per second. On slave and secondary systems, mongostat presents two values separated by a pipe character (e.g. |), in the form of local|replicated commands.
- flushes
-
每秒鐘的 fsync 操作數目。
- mapped
-
The total amount of data mapped in megabytes. This is the total data size at the time of the last mongostat call.
- size
-
The amount of (virtual) memory in megabytes used by the process at the time of the last mongostat call.
- res
-
The amount of (resident) memory in megabytes used by the process at the time of the last mongostat call.
- faults
-
2.1 版已更改。
每秒鐘的頁面錯誤數目。
在 2.1 版之前，該值僅爲在 Linux 主機上運行的 MongoDB 實例提供。
- locked
-
全局寫入鎖定的時間百分比。
Changed in version 2.2: The locked db field replaces the locked % field to more appropriate data regarding the database specific locks in version 2.2.
- locked db
-
2.2 版新特性。
The percent of time in the per-database context-specific lock. mongostat will report the database that has spent the most time since the last mongostat call with a write lock.
This value represents the amount of time that the listed database spent in a locked state combined with the time that the mongod spent in the global lock. Because of this, and the sampling method, you may see some values greater than 100%.
- idx miss
-
訪問加載 btree 節點時需要頁面故障的嘗試的索引百分比。這是一個採樣值。
- qr
-
客戶端等待從 MongoDB 實例讀取數據的隊列長度。
- qw
-
客戶端等待向 MongoDB 實例寫入數據的隊列長度。
- ar
-
執行讀取操作的活動客戶端的數目。
- aw
-
執行寫入操作的活動客戶端的數目。
- netIn
-
The amount of network traffic, in bytes, received by the MongoDB instance.
This includes traffic from mongostat itself.
- netOut
-
The amount of network traffic, in bytes, sent by the MongoDB instance.
This includes traffic from mongostat itself.
- conn
-
打開連接的總數。
- set
-
副本集的名稱（如適用）。