§ 2024-05-18

• yushei-dtk-server is 192.168.2.235

ysadmin@yushei-dtk-server:~$ mongostat --host ys20220318/redisMongo03.yushei.com.tw:27017 --username siteRootAdmin --password b23258585 --authenticationDatabase admin --discover

redisMongo03.yushei.com.tw:27017     *0     1     *0     *0       3     4|0  0.2% 65.4%       0 6.52G 3.85G 0|0 0|0  6.17k   59.6k   60 ys20220318  SLV May 18 08:19:44.318

• explanation

• Host

  • (redisMongo03.yushei.com.tw:27017):, The hostname and port of the MongoDB instance being monitored.

• insert (*0):

  • Number of insert operations per second. A *0 indicates less frequent insert operations than the sampling interval can detect.

• query (1):

  • Number of query operations per second. Here, it's 1 query operation per second.

• update (*0):

  • Number of update operations per second. A *0 indicates less frequent update operations than the sampling interval can detect.

• delete (*0):

  • Number of delete operations per second. A *0 indicates less frequent delete operations than the sampling interval can detect.

• getmore (3):

  • Number of getmore operations per second, which are used to fetch more results from cursor queries.

• command (4|0):

  • Number of command operations per second. 4 indicates general database commands per second, and 0 might indicate additional sub-commands or context.

• % dirty (0.2%):

  • Percentage of data in the cache that is dirty and needs to be flushed to disk.

• % used (65.4%):

  • Percentage of the cache that is currently in use.

• flushes (0):

  • Number of flushes to disk per second.

• vsize (6.52G):

  • Virtual memory size used by the MongoDB process.

• res (3.85G):

  • Resident memory size (physical memory) used by the MongoDB process.

• qr|qw (0|0):

  • Queue lengths for clients waiting for read (qr) and write (qw) operations. Both are 0 here, indicating no clients are waiting.

• ar|aw (0|0):

  • Number of active clients performing read (ar) and write (aw) operations. Both are 0 here, indicating no active clients.

• netIn (6.17k):

  • Amount of network traffic coming into the MongoDB instance per second (6.17 kilobytes).

• netOut (59.6k):

  • Amount of network traffic going out of the MongoDB instance per second (59.6 kilobytes).

• conn (60):

  • Number of active connections to the MongoDB instance.

• repl (ys20220318):

  • A custom field or identifier related to the replica set configuration. This seems to be specific to your setup.

• role (SLV):

  • The role of the MongoDB instance in the replica set. SLV stands for Slave, which is a secondary node in the replica set.

• timestamp (May 18 08:19:44.318):

  • The timestamp when this statistic was recorded.

redisMongo04.yushei.com.tw:27017     *0    *0     *0     *0       0     1|0  0.1% 79.5%       0 4.70G 2.89G 0|0 0|0   263b   54.2k   24 ys20220318  SEC May 18 08:19:44.333
redisMongo05.yushei.com.tw:27017     *0    *0     *0     *0       0     2|0  0.3% 69.2%       0 4.05G 2.40G 0|0 0|0   849b   61.7k   23 ys20220318  SEC May 18 08:19:44.347

```

    Host:
        The hostname and port of the MongoDB instance being monitored (redisMongo03.yushei.com.tw:27017, etc.).

    insert:
        Number of insert operations per second (*0, *0, *0).

    query:
        Number of query operations per second (1, *0, *0).

    update:
        Number of update operations per second (*0, *0, *0).

    delete:
        Number of delete operations per second (*0, *0, *0).

    getmore:
        Number of getmore operations per second (used to fetch more results from cursor queries) (3, 0, 0).

    command:
        Number of command operations per second (general database commands) (4|0, 1|0, 2|0).

    % dirty:
        Percentage of dirty data in the cache (0.2%, 0.1%, 0.3%).

    % used:
        Percentage of the cache that is being used (65.4%, 79.5%, 69.2%).

    flushes:
        Number of flushes to disk per second (0, 0, 0).

    vsize:
        Virtual memory usage (6.52G, 4.70G, 4.05G).

    res:
        Resident memory usage (3.85G, 2.89G, 2.40G).

    qr|qw:
        Queue lengths for clients waiting for read and write operations (0|0, 0|0, 0|0).

    ar|aw:
        Active clients performing read and write operations (0|0, 0|0, 0|0).

    netIn:
        Network traffic in (amount of data received per second) (6.17k, 263b, 849b).

    netOut:
        Network traffic out (amount of data sent per second) (59.6k, 54.2k, 61.7k).

    conn:
        Number of active connections to the database (60, 24, 23).

    time:
        The timestamp of the report (May 18 08:19:44.318, May 18 08:19:44.333, May 18 08:19:44.347).

    repl:
        Replication status:
            SLV: Slave (Secondary node).
            SEC: Secondary node.

Interpreting the Data:

    Operation Metrics: The insert, query, update, delete, getmore, and command columns show the rate of operations. A *0 means that the operation is occurring less frequently than the sampling interval can detect.
    Memory Usage: vsize and res columns indicate virtual and resident memory usage. These values are important for understanding how much memory the MongoDB instance is consuming.
    Cache Usage: The % dirty and % used columns provide insights into the cache's state. High dirty percentages can indicate that a lot of data needs to be written to disk.
    Network Traffic: netIn and netOut show the network activity, which can indicate how much data is being received and sent by the MongoDB instance.
    Connections and Clients: The conn column shows the number of active connections. High values here might suggest heavy usage or potential connection pooling issues.
    Replication Status: The repl column shows the role of each member in the replica set (secondary nodes in this case).

By regularly monitoring these metrics, you can get a good sense of your MongoDB replica set's health and performance, allowing you to identify and address any issues promptly.