baw-workers

baw-workers

Code that runs as background jobs for the web application. Workers can process various long-running or intensive tasks. File storage provides helper methods for calculating paths to original and cached files.

This app can either be used as a library (when used from the web app) or used as in an independent application (when used from the tasks/run_worker.rake rakefile)

This code was historically maintained in https://github.com/QutEcoacoustics/baw-workers but was incorporated into this repository for ease of maintenance.

Old readme follows:

Actions

This project provides four actions. Actions are classes that implement a potentially long-running process.

Analysis

Runs analysers over audio files. This action analyses an entire single audio file.

1. Resque jobs can be queued from baw-server and processed later by a Resque dequeue worker.
2. A directory can be analysed manually by providing the settings for a single audio file in yaml format for the the analysis_config_file parameter.

Audio Check

Runs checks on original audio recording files. This action checks an entire single audio file.

• Gets audio files to check from a csv file in a specific format by specifying csv_file.

Media

Cuts audio files and generates spectrograms.

• Resque jobs can be queued on demand from baw-server and processed later by a Resque dequeue worker.

Dependencies

You may need to install some additional tools for working with audio and images, and for processing long-running tasks. See baw-audio-tools for more information.

File Storage

There are classes for working with file storage paths:

• original audio files
• caches for
  • cut audio
  • generated spectrograms
  • analysis results.

Running Workers

A worker runs an action. Actions are simply a process to follow. Actions can get input from the settings file when run standalone and/or from Resque jobs (when running as a Resque dequeue worker).

Then answer these questions:

• which environment? (e.g. staging, production, development, test)
• which worker? (e.g. audio_check, harvester, media, analysis)
• which processing model? (e.g. standalone, resque)

Based on the answers to these questions

• pick an existing config file (and check that the settings match the file name),
• or create a new config file based on an existing one, named in a similar way.

Once you've got your config file, then a worker can be started. Workers are run using rake tasks. A list of the available rake tasks can be obtained by running this command in the baw-workers cloned directory or the directory containing your Gemfile:

bundle exec rake -T

There are two steps that a worker can run:

• preliminary processing (step 1), which can finish by adding a job to a Resque queue or continuing directly to step 2.
• final processing (step 2), which can start by reserving a job from a Resque queue or directly receiving data from step 1.

There are three ways to run a worker:

• standalone: this will run steps 1 and 2 sequentially in the same process
• Resque enqueue: this will run step 1 and enqueue a job using Resque
• Resque dequeue: this will reserve a job using Resque and run step 2

Configuration Hints

Some things to check and look out for when creating and modifying worker config files.

settings.resque.queues_to_process

This setting is only needed when running a Resque dequeue worker. It specifies a priority array of the Resque queues to reserve jobs from. The jobs in a queue specify the action class that will be used to process that job.

settings.resque.connection

The connection settings are passed directly to Resque to configure the Redis connection.

settings.resque.namespace

The Redis namespace. This should usually be left as 'resque'.

settings.resque.background_pid_file

Specify a background_pid_file to have a Resque dequeue worker run in the background. The output_log_file and error_log_file settings will only be used when a Resque dequeue worker is running in the background.

settings.actions

Each action has some settings specific to that action. An action is the actual processing that job arguments will be used to carry out.

Every action has a queue setting. The queue is the name of the queue the action will add jobs to when running as a Resque enqueue worker. See the Actions section below for more information about action-specific settings.

log_level settings

Each log_level setting is independent of the others.

Examples for running a worker

Replace 'settings_file' with the full path to the settings file to use for the worker. Other parameters are described in the Actions section below.

Standalone

bundle exec rake baw:harvest:standalone:from_files[settings_file,harvest_dir]            # Harvest audio files directly
# media action can only be run as a Resque dequeue worker

Resque enqueue

bundle exec rake baw:analysis:resque:from_files[settings_file,analysis_config_file]      # Enqueue files to analyse using Resque
bundle exec rake baw:audio_check:resque:from_csv[settings_file,csv_file]                 # Enqueue audio recording file checks from a csv file to be processed using Resque worker
bundle exec rake baw:harvest:resque:from_files[settings_file,harvest_dir]                # Enqueue files to harvest using Resque
# media action can only be run as a Resque dequeue worker

Resque dequeue

A Resque dequeue worker can process any queue with any type of job.

bundle exec rake baw:worker:current[settings_file]                                       # List running workers
bundle exec rake baw:worker:run[settings_file]                                           # Run a resque:work with the specified settings file
bundle exec rake baw:worker:run_scheduler[settings_file]                                 # Run resque:scheduler with the specified settings file
bundle exec rake baw:worker:setup[settings_file]                                         # Run a resque:work with the specified settings file
bundle exec rake baw:worker:stop_all[settings_file]                                      # Quit running workers