Base

Interface definition and base implementation for all subprocess managers.

Interface

class servermgr.base.ManagerInterface

This abstract class defines the interface implemented by all Managers.

health()

Check the health of the worker subprocess.

Raises :WorkerError if the worker subprocess is not responding.

ready_wait(timeout=10.0)

Wait for the worker to be ready to handle requests.

Parameters:

• timeout (float, seconds) – Give the server this many seconds to start. If the timeout expires before the server has started, kill the server and raise WorkerError.

Raises :

WorkerError if the worker is not ready within the time limit.

start(wait=True, timeout=10.0)

Start the worker subprocess.

Parameters:

• wait – If true, call self.ready_wait() after starting the subprocess.
• timeout (float, number of seconds) – When calling ready_wait(), use this timeout value.

stop(wait=True)

Stop the worker subprocess.

Parameters:

• wait (boolean) – If True, wait for the worker to exit.

wait()

Wait for the worker process to exit.

Exceptions

exception servermgr.base.WorkerError(exception, *args, **kwargs)

Exception raised when a Worker fails to start or fails to respond.

Utility Functions

servermgr.base.address_in_use(host, port)

Check to see if there is a listener on host:port.

Parameters:

• host (string) – the interface to check;
• port (int) – the post to check;

Returns:

True if there is a listener, else False.

servermgr.base.address_free_check(host, port)

Raise an exception if host:port is in use.

Parameters:

• host (string) – the interface to check;
• port (int) – the post to check;

Raises :

WorkerError if the address is in use.

Classes

class servermgr.base.Manager(name='<unnamed>', **kwargs)

Parameters:

• name – Name of manager, displayed in error and log messages.
• kwargs – Any other keyword args will be stored in self.kwargs.

This is the base implementation of the Manager class.

Implementations are provided for the following methods:

• ready_wait()
• stop()
• wait()

The following methods must be implemented by the subclass:

• health()
• start()

health()

Check the worker subprocess health.

Raises :NotImplementedError must be implemented by subclass.

process

Return the process object.

ready_wait(timeout=10.0, verbose=False)

Wait until the worker subprocess is responding to requests.

Parameters:

• timeout (float, seconds) – Give the server this many seconds to start. If the timeout expires before the server has started, kill the server and raise WorkerError.

Raises :

WorkerError if the worker is not ready within the time limit.

Raises :

WorkerError if there is no subprocess.

start(wait=True, timeout=10.0)

Start the worker subprocess.

Raises :NotImplementedError must be implemented by subclass.

stop(wait=True)

Terminate the worker subprocess.

Parameters:

• wait (boolean) – If True, wait for the worker to exit.

wait()

Wait for the worker process to exit.