tcpserver acts like a server push version of stdout over TCP

The tcpserver driver is based on the behavior of the stdout driver. You configure the tcpserver driver in exactly the same way as the stdout driver, except for the additional parameters shown here.

The tcpserver driver listens on a configured host and port (a socket address). When any clients are connected, the internal queue is buffered to them as long as there is data in it. For each cycle of data in the internal buffer, one of the connected clients will get it in unspecified order.

If the buffer is primed with data when a client is connected it will get all of the data at once. After this, data is added to the buffer at whatever cyclerate the activity is configured for. If you add data to the buffer faster than you can consume it with connected clients, you will have a number of failed operations.

However, the opposite is not true. You should generally ensure that you can consume the data as fast as you provide it, and the error counts give you a relatively easy way to verify this. If you wish to disable this behavior, set the retries to a very high value. In this case, the tries metric will still give you some measure of internal buffer saturation.


Run a stdout activity named 'stdout-test', with definitions from activities/stdout-test.yaml

... driver=tcpserver yaml=stdout-test

Driver Parameters

  • retry_delay - The internal retry frequency at which the internal cycle loop will attempt to add data to the buffer. This applies when the internal buffer is full and no clients are consuming data from it.

    • unit: milliseconds
    • default: 1000
    • dynamic: false
  • retries - The number of retries which the internal cycle loop will attempt before marking a row of output as failed.

    • default: 3
    • dynamic: false
  • ssl - boolean to enable or disable ssl

    • default: false
    • dynamic: false

    To enable, specifies the type of the SSL implementation with either jdk or openssl.

    Additional parameters may need to be provided.

  • host - this is the name to bind to (local interface address)

    • default: localhost
    • dynamic: false
  • port - this is the name of the port to listen on

    • default: 12345
    • dynamic: false
  • capacity - the size of the internal blocking queue

    • default: 10
    • unit: lines of output
    • dynamic: false

Statement Format

Refer to the help for the stdout driver for details.