Processor

Core class for other components to inherit.

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class sosw.app.LambdaGlobals[source]

Global placeholder for global_vars that we want to preserve in the lifetime of the Lambda Container. e.g. once initiailised the given Processor, we keep it alive in the container to minimize warm-run time.

This namespace also contains the lambda_context which should be reset by get_lambda_handler method. See Worker examples in documentation for more info.

class sosw.app.Processor(custom_config=None, **kwargs)[source]

Core Processor class template. All the main components (Worker, Orchestrator and Scheduler) inherit from this one. You can also use this class as parent for some of your standalone Lambdas, but we strictly encourage you to use Worker class in case you are running functions under sosw orchestration.

die(message='Unknown Failure')[source]

Logs current Processor stats and message. Then raises RuntimeError with message.

If there is access to publish SNS messages, the method will also try to publish to the topic configured as dead_sns_topic or ‘SoswWorkerErrors’.

Parameters

message (str) – Description of failure.

static get_config(name)[source]

Returns config by name from DynamoDB config or SSM. Override this to provide your config handling method.

Parameters

name – Name of the config

Return type

dict

get_stats(recursive: bool = True)[source]

Return statistics of operations performed by current instance of the Class.

Statistics of custom clients existing in the Processor is also aggregated by default. Clients must be initialized as self.some_client ending with _client suffix (e.g. self.dynamo_client). Clients must also have their own get_stats() methods implemented.

Be careful about circular get_stats() calls from child classes. If required overwrite get_stats() with recursive = False.

Parameters

recursive – Merge stats from self.***_client.

Return type

dict

Returns

Statistics counter of current Processor instance.

init_config(custom_config: Optional[Dict] = None)[source]

By default tries to initialize config from DEFAULT_CONFIG or as an empty dictionary. After that, a specific custom config of the Lambda will recursively update the existing one. The last step is update config recursively with a passed custom_config.

Overwrite this method if custom logic of recursive updates in configs is required

Parameters

custom_config (Dict) – dict with custom configurations

reset_stats(recursive: bool = True)[source]

Cleans statistics other than specified for the lifetime of processor. All the parameters with prefix ‘total_’ are also preserved.

The function makes sense if your Processor lives outside the scope of lambda_handler.

Be careful about circular get_stats() calls from child classes. If required overwrite reset_stats() with recursive = False.

Parameters

recursive – Reset stats from self.***_client.

sosw.app.get_lambda_handler(processor_class, global_vars=None, custom_config=None)[source]

Return a reference to the entry point of the lambda function.

Parameters
  • processor_class – Callable processor class.

  • global_vars – Lambda’s global variables (processor, context).

  • custom_config – Custom configuration to pass the processor constructor.

Returns

Function reference for the lambda handler.