simpleflow 0.21.13

Python library for dataflow programming with Amazon SWF

Simpleflow

[](http://badge.fury.io/py/simpleflow) [](https://travis-ci.org/botify-labs/simpleflow)

Simpleflow is a Python library that provides abstractions to write programs in the distributed dataflow paradigm. It coordinates the execution of distributed tasks with Amazon SWF.

It relies on futures to describe the dependencies between tasks. A Future object models the asynchronous execution of a computation that may end. It tries to mimic the interface of the Python concurrent.futures library.

Features

• Provides a Future abstraction to define dependencies between tasks.
• Define asynchronous tasks from callables.
• Handle workflows with Amazon SWF.
• Implement replay behavior like the Amazon Flow framework.
• Handle retry of tasks that failed.
• Automatically register decorated tasks.
• Encodes/decodes large fields to S3 objects transparently (aka "jumbo fields").
• Handle the completion of a decision with more than 100 tasks.
• Provides a local executor to check a workflow without Amazon SWF (see simpleflow --local command).
• Provides decider and activity worker process for execution with Amazon SWF.
• Ships with the simpleflow command. simpleflow --help for more information about the commands it supports.

You can read more in the Features section of the documentation.

Overview

Please read and even run the demo script to have a quick glance of simpleflow commands. To run the demo you will need to start decider and activity worker processes.

Start a decider with::

$ simpleflow decider.start --domain TestDomain --task-list test examples.basic.BasicWorkflow

Start an activity worker with::

$ simpleflow worker.start --domain TestDomain --task-list quickstart

Then execute ./extras/demo.

More informations

Read the main documentation at https://botify-labs.github.io/simpleflow/.

Changelog

0.21.13

0.21.12

• Update subprocess32 to 3.5.x (#366)

0.21.11

• task/340/remote-syslog-support (#345)

0.21.10

• task/DATA-7023/local_executor_run_id (#362)
• Enhancement 364: add ChildWorkflowTask class (#365)
• canvas: support WorkflowTask in the Group() canvas (#360)

0.21.9

• Prune worker process tree. (#355)

0.21.8

• swf: WorkflowTask: add the possibility to use a custom task list (#356)
• tests/moto_compat.py: new file (#358)
• Add BOTO_CONFIG=/dev/null to scripts/test (#357)
• spelling fix, failuer->failure (#353)

0.21.7

• Fix reading requirements-dev.txt again (#352)

0.21.6

• Fix reading requirements-dev.txt :roll_eyes: (#351)

0.21.5

• Remove explicit handling of AWS credentials from env vars. (#347)
• Enhancement: use moto 1.x (#349)
• Add optional S3 server-side encryption (#350)

0.21.4

0.21.3

• Don't try creating ActivityType's multiple times (#342)

0.21.2

0.21.1

• simpleflow.execute.python: handle huge args (#339)

0.21.0

• Feature: custom logic on retry (#332)

0.20.8

• Expose simpleflow.utils.serialize_complex_object() function (#336)

0.20.7

• Feature: raises_on_failure and retry on workflow (#334)

0.20.6

• Improve tests and fix jumbo fields decoding on failure (#330)
• Remove future.standard_library.install_aliases() (#329)

0.20.5

• Add 'simpleflow binaries.download' command

0.20.4

• Fail activity task on k8s job spawning failure (#328)

0.20.3

• Small settings improvements (#323)

0.20.2

• add meta to metrology, upload stats only at the end of a task (#324)

0.20.1

• inject context into python subprocess (#322)

0.20.0

• Feature/318/simpleflow download binary (#321)

0.19.2

• Slow jumbo cache fixes (#320)

0.19.1

0.19.0

• Kubernetes integration (#313)

0.18.15

• Bugfix: propagate signal (#312)
• Enhancement: inherit tag list (#314)
• • blank SWF decision execution context when needed

• rename ambiguous "execution_context" to "run_context" (#310)

0.18.14

• Update the link to the documentation (#306)
• Fork on each decision task to protect against memory leaks (#200) (#308)
• Don't truncate too long fields, raise instead (closes #307) (#309)

0.18.13

• Fix diskcache OperationalError (#303)

0.18.12

• Enhancement: save waiting_signals in the execution context (#300)
• Mark flaky tests as expected to fail (#301)

0.18.11

• Allow Workflow instances in Group (#299)

0.18.10

• Don't raise when ThrottlingException occur on RecordActivityTaskHeartbeat endpoint (#297)

0.18.9

• Fix activity.rerun not working with class based tasks (#289)
• Add a new option (and parameter) --kill-children (#292)

0.18.8

• Move workers cleanup/start outside SIGCHLD handler (#290)

0.18.7

• Fix MANIFEST.in so README.md is included in final package

0.18.6

• Add a new timeout parameter (#286)

0.18.5

• Documentation overhaul (#284)
• Add a release script (closes #179) (#287)

0.18.4

• Improve process stopping (#283)

0.18.3

• Enhancement/276/improve execute python (#280)

0.18.2

• Bugfix: task failed details (#281)
• Add sets support to json_dumps (#275)

0.18.1

• Add back get_workflow_history

0.18.0

• Implement "jumbo" fields (#265)

0.17.0

• Enhancement/272/implement workflow cancelation (#273)
• Bugfix: 270: signals improvements (#271)
• Enhancement: timer: get_event_details (#269)
• Append "/" to get_step_path_prefix (#268)
• Enhancement/misc (#266)
• Repair reruns successful child workflows (#191)

0.16.0

• Feature: timers (#258)

0.15.7

• Kill worker on UnknownResourceFault's during a heartbeat (#88) (#263)
• Sort keys by default in json_dumps (#264)

0.15.6

• Fix step attribute propagation (#261)
• Enhancement: get_event_details (#235)

0.15.5

• Enhancement: distinguish raises_on_failure between tasks and groups (#255)
• Add time constants
• Relax activity.with_attributes timeouts types

0.15.4

• Enhancement: add canvas option break_on_failure (#253)
• Compute task_id from ActivityTask if has get_task_id method (#237)
• Another case of wrong task list (#234)

0.15.3

• make raises_on_failure=True on step activities (#249)
• SWF: support for non-Python tasks (#219)
• Fix get_step_path_prefix
• Make MarkerTask's idempotents

0.15.2

• mark when a step is scheduled before it's executed (#243)

0.15.1

• Enhancement: better activity type reason (#238)
• Fix workers not catching errors during dispatch() step (#246)
• Fix canvas.Chain send_result regression (#247)

0.15.0

• Feature: steps (#221)
• Make activity task result optional (#225)
• Use details in addition to name to find markers (#227)
• Logging: add exception information (#163)
• swf/actors: support 'Message' key (#224)
• Implement markers (#216) (#217)
• Add retry on swf.process.Poller.poll and fail (#208)

0.14.2

• propagate_attribute: skip signal objects (#215)
• Local executor: check add_activity_task (#215)

0.14.1

• Don't send exception up if raises_on_failure is false (#213)
• Fix UnicodeDecodeError on windows machine (#211)
• Try to use less memory (#209)
• Standalone mode: use created task list for children activities (#207)

0.14.0

• Fix workers not stopping in case they start during a shutdown (#205)
• Add support for SWF signals (#188)
• Improvements on canvas.Group (#204)

0.13.4

• Implement metrology on SWF and local workflows (#186)

0.13.3

• Try..except pass for NoSuchProcess (#182)

0.13.2

• Add optional canvas (#193)
• Reorganize tests/ directory (#198)
• Relax DeciderPoller task list check (#201)
• Implement priorities on SWF tasks (#199)

0.13.1

• Fix SWF executor not accepting ActivityTask's in submit() method (#196)

0.13.0

• Implement child workflow (#74)
• Don't schedule idempotent tasks multiple times (#107)
• Child workflow ID: use parent's id to generate

0.12.7

• Control SWF processes identity via environment (#184)

0.12.6

• Replace execution object with a more flexible get_execution_method() (#177)
• Fix README_SWF.rst format (#175)
• Fix CONTRIBUTING.rst format
• docs/conf.py: remove relative import

0.12.5

• Executor: expose workflow execution (#172)

0.12.4

• Avoid returning too big responses to RespondDecisionTaskCompleted endpoint (#166)
• Worker: remove useless monitor_child (#168)

0.12.3

• Add max_parallel option in Group (#164)

0.12.2

• Make the dynamic dispatcher more flexible (#161)
• Fix README.rst format (#160)
• Tiny command-line usability fixes (#158)

0.12.1

• Don't override passed "default" in json_dumps() (#155)
• Expose activity context (#156)

0.12.0

• Improve process management (#142)

0.11.17

• Don't reap children in the back of multiprocessing (#141)
• Don't force to pass a workflow to activity workers (#133)
• Don't override the task list if not standalone (#139)
• Split FuncGroup submit (#146)
• CI: Test on python 3 (#144)
• Decider: use workflow's task list if unset (#148)

0.11.16

• Refactor: cleanups and many python 3 compatibility issues fixed (#135)
• Introduce AggregationException to inspect exceptions inside canvas.Group/Chain (#92)
• Improve heartbeating, now enabled by default on activity workers (#136)

0.11.15

• Fix tag_list declaration in case no tag is associated with the workflow
• Fix listing workflow tasks not handling "scheduled" (not started) tasks correctly
• Fix CSV formatter outputing an extra "None" at the end of the output
• Fix 'simpleflow activity.rerun' resolving the bad function name if not the last event

0.11.14

• Various little fixes around process management, heartbeat, logging (#110)

0.11.13

• Add ability to provide a 'run ID' with 'simpleflow standalone --repair'

0.11.12

• Fix --tags argument for simpleflow standalone (#114)
• Improve tests and add integration tests (#116)
• Add 'simpleflow activity.rerun' command (#117)

0.11.11

• Fix a circular import on simpleflow.swf.executor

0.11.10

• Fix previous_history initialization (#106)
• Improve WorkflowExecutionQueryset default date values (#111)

0.11.9

• Add a --repair option to simpleflow standalone (#100)

0.11.8

• Retry boto.swf connection to avoid frequent errors when using IAM roles (#99)

0.11.7

Same as 0.11.6 but the 0.11.6 on pypi is broken (pushed something similar to 0.11.5 by mistake)

0.11.6

• Add issubclass_ method (#96)
• Avoid duplicate logs if root logger has an handler (#97)
• Allow passing SWF domain via the SWF_DOMAIN environment variable (#98)

0.11.5

• Don't mask activity cancel exception (#84)
• Propagate all decision response attributes up to Executor.replay() (#76, #94)

0.11.4

• ISO dates in workflow history #91
• Fix potential infinite retry loop #90

0.11.3

• Fix replay hooks introduced in 0.11.2 (#86)
• Remove python3 compatibility from README (which was not working for a long time)

0.11.2

• Add new workflow hooks (#79)

0.11.1

• Fix logging when an exception occurs

0.11.0

• Merge swf package into simplefow for easier maintenance.

0.10.4 and below

Sorry changes were not documented for simpleflow <= 0.10.x.