Tutorial

    1. Install nats-top

    You may need to run the following instead:

    2. Start the NATS server with monitoring enabled

      Result:

      1. nats-server version 0.6.6 (uptime: 2m2s)
      2. Server:
      3.   Load: CPU:  0.0%  Memory: 6.3M  Slow Consumers: 0
      4.   In:   Msgs: 0  Bytes: 0  Msgs/Sec: 0.0  Bytes/Sec: 0
      5.   Out:  Msgs: 0  Bytes: 0  Msgs/Sec: 0.0  Bytes/Sec: 0
      7. Connections: 0
      8.   HOST                 CID      SUBS    PENDING     MSGS_TO     MSGS_FROM   BYTES_TO    BYTES_FROM  LANG     VERSION

      4. Run NATS client programs

      Run some NATS client programs and exchange messages.

      5. Check nats-top for statistics

      1. nats-server version 0.6.6 (uptime: 30m51s)
      2. Server:
      3.   Load: CPU:  0.0%  Memory: 10.3M  Slow Consumers: 0
      4.   In:   Msgs: 56  Bytes: 302  Msgs/Sec: 0.0  Bytes/Sec: 0
      5.   Out:  Msgs: 98  Bytes: 512  Msgs/Sec: 0.0  Bytes/Sec: 0
      7.   HOST                 CID      SUBS    PENDING     MSGS_TO     MSGS_FROM   BYTES_TO    BYTES_FROM  LANG     VERSION
      8.   ::1:58651            6        1       0           52          0           260         0           go       1.1.0
      9.   ::1:58922            38       1       0           21          0           105         0           go       1.1.0
      10.   ::1:58953            39       1       0           21          0           105         0           go       1.1.0

      In nats-top, enter the command o followed by the option, such as bytes_to. You see that nats-top sorts the BYTES_TO column in ascending order.

      7. Use different sort options

      Use some different sort options to explore nats-top, such as:

      cid, subs, pending, msgs_to, msgs_from, bytes_to, bytes_from, lang, version

      8. Display the registered subscriptions.

      In nats-top, enter the command s to toggle displaying connection subscriptions. When enabled, you see the subscription subject in nats-top table:

      1. nats-server version 0.6.6 (uptime: 1h2m23s)
      2. Server:
      3.   Load: CPU:  0.0%  Memory: 10.4M  Slow Consumers: 0
      4.   In:   Msgs: 108  Bytes: 643  Msgs/Sec: 0.0  Bytes/Sec: 0
      5.   Out:  Msgs: 185  Bytes: 1.0K  Msgs/Sec: 0.0  Bytes/Sec: 0
      7. Connections: 3
      8.   HOST                 CID      SUBS    PENDING     MSGS_TO     MSGS_FROM   BYTES_TO    BYTES_FROM  LANG     VERSION SUBSCRIPTIONS
      9.   ::1:59708            115      1       0           6           0           48          0           go       1.1.0   foo.bar
      10.   ::1:59758            122      1       0           1           0           8           0           go       1.1.0   foo

      Use the q command to quit nats-top.

      10. Restart nats-top with a specified query

      For example, to query for the connection with largest number of subscriptions:

      1. % nats-top -n 1 -sort subs