A queue/jobs system based on redis-limpyd, a redis orm (sort of) in python
Project description
redis-limpyd-jobs
A queue/jobs system based on redis-limpyd (redis orm (sort of) in python)
Where to find it:
Github repository: https://github.com/twidi/redis-limpyd-jobs
Pypi package: https://pypi-hypernode.com/pypi/redis-limpyd-jobs
Documentation: https://documentup.com/twidi/redis-limpyd-jobs
Note that you actually need the redis-limpyd-extensions in addition to redis-limpyd (both installed via pypi)
How it works
redis-limpyd-jobs provides three limpyd models (Queue, Job, Error), and a Worker class.
These models implement the minimum stuff you need to run jobs asynchronously:
Use the Job model to store things to do
The Queue model will store a list of jobs, with a priority system
The Error model will store all errors
The Worker class is to be used in a process to go through a queue and run jobs
Simple example
from limpyd_jobs import STATUSES, Job, Worker
# The function to run when a job is called by the worker
def do_stuff(job, queue):
# here do stuff with your job
# Create a first job, name 'job:1', in a queue named 'myqueue', with a
# priority of 1. The higher the priority, the sooner the job will run
job1 = Job.add_job(identifier='job:1', queue_name='myqueue', priority=1)
# Add another job in the same queue, with a higher priority, and a different
# identifier (if the same was used, no new job would be added, but the
# existing job's priority would have been updated)
job2 = Job.add_job(identifier='job:2', queue_name='myqueue', priority=2)
# Create a worker for the queue used previously, asking to call the
# "do_stuff" function for each job, and to stop after 2 jobs
worker = Worker(name='myqueue', callback=do_stuff, max_loops=2)
# Now really run the job
worker.run()
# Here our jobs are done, our queue is empty
queue = Queue.get_queue('myqueue')
# nothing waiting
print queue.waiting.lmembers()
>> []
# two jobs in success
print queue.success.lmembers()
>> ['jobs:job:1', 'jobs:job:2']
# Check our jobs statuses
print job1.status.hget() == STATUSES.SUCCESS
>> True
print job2.status.hget() == STATUSES.SUCCESS
>> True
You notice how it works:
Job.add_job to create a job
Worker() to create a worker, with callback argument to set which function to run for each job
worker.run to launch a worker.
Notice that you can run as much workers as you want, even on the same queue name. Internally, we use the blpop redis command to get jobs atomically.
But you can also run only one worker, having only one queue, doing different stuff in the callback depending on the idenfitier attribute of the job.
Workers are able to catch SIGINT/SIGTERM signals, finishing executing the current job before exiting. Useful if used, for example, with supervisord.
If you want to store more information in a job, queue or error, or want to have a different behavior in a worker, it’s easy because you can create subclasses of everything in limpyd-jobs, the limpyd models or the Worker class.
Models
Job
A Job stores all needed informations about a task to run.
Job fields
By default it contains a few fields:
identifier
A string (InstanceHashField, indexed) to identify the job.
When using the (recommended) add_job class method, you can’t have many jobs with the same identifier in a waiting queue. If you create a new job with an identifier while an other with the same is still in the same waiting queue, what is done depends on the priority of the two jobs: - if the new job has a lower (or equal) priority, it’s discarded - if the new job has a higher priority, the priority of the existing job is updated to the higher.
In both cases the add_job class method returns the existing job, discarding the new one.
A common way of using the identifier is to, at least, store a way to identify the object on which we want the task to apply: - you can have one or more queue for a unique task, and store only the id of an object on the identifier field - you can have one or more queue each doing many tasks, then you may want to store the task too in the identifier field: “task:id”
Note that by subclassing the Job model, you are able to add new fields to a Job to store the task and other needed parameters, as arguments (size for a photo to resize, a message to send…)
status
A string (InstanceHashField, indexed) to store the actual status of the job.
It’s a single letter but we provide a class to help using it verbosely: STATUSES
from limpyd_jobs import STATUSES
print STATUSES.SUCCESS
>> "s"
When a job is created via the add_job class method, its status is set to STATUSES.WAITING. When it selected by the worker to execute it, the status passes to STATUSES.RUNNING. When finished, it’s one of STATUSES.SUCCESS or STATUSES.ERROR. An other available status is STATUSES.CANCELED, useful if you want to cancel a job without removing it from its queue.
You can also display the full string of a status:
print STATUSES.by_value(my_job.status.hget())
priority
A string (InstanceHashField, indexed, default = 0) to store the priority of the job.
The priority of a job determines in which Queue object it will be stored. A worker listen for all queues with a given name and different priorities, but respecting the priority (reverse) order: the higher the priority, the sooner the job will be executed.
We choose to use the “`”higher priority is better” way of doing things to give the possibility to always add a job in a higher priority than any other ones.
Directly updating the priority of a job will not change the queue in which it’s stored. But when you add a job via the (recommended) add_job class method, if a job with the same identifier exists, its priority will be updated (only if the new one is higher) and the job will be moved to the higher priority queue.
start
A string (InstanceHashField) to store the date and time (a string representation of datetime.utcnow()) of the time the job was fetched from the queue, just before the callback is called.
It’s useful in combination of the end field to calculate the job duration.
end
A string (InstanceHashField) to store the date and time (a string representation of datetime.utcnow()) of the moment the job was set as finished or in error, just after the has finished.
It’s useful in combination of the start field to calculate the job duration.
Job attributes
There is only one attribute on the Job model, but it is very important:
queue_model
When adding jobs via the add_job method, the model defined in this attribute will be used to get or create a queue. It’s set by default to Queue but if you want to update it to your own model, you must subclass the Job model too, and update this attribute.
Note that if you don’t subclass the Job model, you can pass the queue_model argument to the add_job method.
Job properties and methods
The Job model contains only one property, and no methods:
duration (property)
The duration property simply returns the time used to compute the job. The return value is a datetime.timedelta object if the start and end fields are set, or None on the other case.
Job class methods
The Job model provides a single, but very important, class method:
add_job
The add_job class method is the main (and recommended) way to create a job. It will check if a job with the same identifier already exists in a waiting queue and if one is found, update its priority (and move it in the correct queue). If no existing job is found, a new one will be created and added to a queue.
Arguments:
identifier The value for the identifier field.
queue_name The queue name in which to save the job.
priority=0 The priority of the new job, or the new priority of an already existing job, if this priority is higher of the existing one.
queue_model The model to use to store queues. By default, it’s set to Queue, defined in the queue_model attribute of the Job model. If the argument is not set, the attribute will be used. Be careful to set it as attribute in your subclass, or as argument in add_job or the default Queue model will be used and jobs won’t be saved in the expected queue model.
prepend=False By default, all new jobs are added at the end of the waiting list (and taken from the start, it’s a fifo list), but you can force jobs to be added at the beginning of the waiting list to be the first to be executed, simply by setting the prepend argument to True. If the job already exists, it will be moved at the beginning of the list.
If you use a subclass of the Job model, you can pass additional arguments to the add_job method simply by passing them as named arguments, they will be save if a new job is created (but not if an existing job is found in a waiting queue)
Queue
A Queue stores a list of waiting jobs with a given priority, and keep a list of successful jobs and ones on error.
Queue fields
By default it contains a few fields:
name
A string (InstanceHashField, indexed), used by the add_job method to find the queue in which to store it. Many queues can have the same name, but different priorities.
This name is also used by a worker to find which queues it needs to wait for.
priority
A string (InstanceHashField, indexed, default = 0), to store the priority of a queue’s jobs. All jobs in a queue are considered having this priority. It’s why, as said for the property fields of the Job model, changing the property of a job doesn’t change its real property. But adding (via the add_job class method of the Job model) a new job with the same identifier for the same queue’s name can update the job’s priority by moving it to another queue with the correct priority.
As already said, the higher the priority, the sooner the jobs in a queue will be executed. If a queue has a priority of 2, and another queue of the same name has a priority of 0, or 1, all jobs in the one with the priority of 2 will be executed (at least fetched) before the others, regardless of the number of workers.
waiting
A list (ListField) to store the primary keys of job in the waiting status. It’s a fifo list: jobs are appended to the right (via rpush), and fetched from the left (via blpop)
When fetched, a job from this list is executed, then pushed in the success or error list, depending if the callback raised an exception or not. If a job in this waiting list is not in the waiting status, it will be skipped by the worker.
success
A list (ListField) to store the primary keys of jobs fetched from the waiting list and successfully executed.
error
A list (ListField) to store the primary keys of jobs fetched from the waiting list for which the execution failed.
Queue attributes
The Queue model has no specific attributes.
Queue properties and methods
The Queue model has no specific properties or method.
Queue class methods
The Queue model provides a few class methods:
get_queue
The get_queue class method is the recommended way to get a Queue object. Given a name and a priority, it will return the found queue or create a queue if no matching one exist.
Arguments:
name The name of the queue to get or create.
priority The priority of the queue to get or create.
If you use a subclass of the Queue model, you can pass additional arguments to the get_queue method simply by passing them as named arguments, they will be saved if a new queue is created (but not if an existing queue is found)
get_keys
The get_keys class method returns all the existing queue with a given name, sorted by priority (reverse order: the highest priorities come first). The returned value is a list of redis keys for each waiting lists of matching queues. It’s used internally by the workers as argument to the blpop redis command.
count_waiting_jobs
The count_waiting_jobs class method returns the number of jobs still waiting for a given queue name, combining all priorities.
Arguments:
name The name of the queues to take into accounts.
Error
The Error model is used to store errors from the jobs that are not successfully executed by a worker.
Its main purpose is to be able to filter errors, by queue name, job identifier, date, exception class name or code. You can use your own subclass of the Error model and then store additional fields, and filter on them.
Error fields
idenfitier
A string (InstanceHashField, indexed) to store the identifier of the job that failed.
queue_name
A string (InstanceHashField, indexed) to store the name of the queue the job was in when it failed.
date
A string (InstanceHashField, indexed) to store the date (only the date, not the time) of the error (a string representation of datetime.utcnow().date()). This field is indexed so you can filter errors by date, useful to graph errors.
time
A string (InstanceHashField) to store the time (only the time, not the date) of the error (a string representation of datetime.utcnow().time()).
type
A string (InstanceHashField, indexed) to store the type of error. It’s the class’ name of the originally raised exception.
code
A string (InstanceHashField, indexed) to store the value of the code attribute of the originally raised exception. Nothing is stored here if there is no such attribute.
message
A string (InstanceHashField) to store the string representation of the originally raised exception.
traceback
A string (InstanceHashField) to store the string representation of the traceback of the originally raised exception (the worker may not have filled it)
Error properties and methods
There is only one property on the Error model:
datetime
This property returns a datetime object based on the content of the date and time fields of an Error object.
Error class methods
The Error model provides a single class method:
add_error
The add_error class method is the main (and recommended) way to add an entry on the Error model, by accepting simple arguments that will be break down (when becomes date and time, error becomes code and message)
Arguments:
queue_name The name of the queue the job came from.
identifier The value for the identifier field of the job.
error An exception from which we’ll extract the code and the message.
when=None A datetime object from which we’ll extract the date and time.
If not filled, datetime.utcnow() will be used.
trace=None The traceback, stringyfied, to store.
If you use a subclass of the Error model, you can pass additional arguments to the add_error method simply by passing them as named arguments, they will be save in the object to be created.
The worker(s)
The Worker class
The Worker class does all the logic, working with Queue and Job models.
The main behavior is: - reading queue keys for the given name - waiting for a job available in the queue - executing the job - manage success or error - exit after a defined number of jobs
The class is split in many short methods so that you can subclass it to change/add/remove whatever you want.
Constructor arguments and worker’s attributes
Each of the following worker’s attributes can be set by an argument in the constructor, using the exact same name. It’s why the two are described here together.
name
The name of the worker, used to get all queues with that name. Default to None, but if not set and not defined in a subclass, will raise an ImplementationError.
job_model
The model to use for jobs. By default it’s the Job model included in limpyd_jobs, but you can use a subclass of the default model to add fields, methods…
queue_model
The model to use for queues. By default it’s the Queue model included in limpyd_jobs, but you can use a subclass of the default model to add fields, methods…
error_model
The model to use for saving errors. By default it’s the Error model included in limpyd_jobs, but you can use a subclass of the default model to add fields, methods…
logger_base_name
limpyd_jobs uses the python logging module, so this is the name to use for the logger created for the worker. The default value is LOGGER_BASE_NAME + '.%s', with LOGGER_BASE_NAME defined in limpyd_jobs.workers with a value of “limpyd_jobs”, and ‘%s’ will be replaced by the name attribute.
logger_level
It’s the level set for the logger created with the name defined in logger_base_name.
save_errors
A boolean, default to True, to indicate if we have to save errors in the Error model (or the one defined in error_model) when the execution of the job is not successful.
save_tracebacks
A boolean, default to True, to indicate if we have to save the tracebacks of exceptions in the Error model (or the one defined in error_model) when the execution of the job is not successful (and only if save_errors is True)
max_loops
The max number of loops (fetching + executing a job) to do in the worker lifetime, default to 1000. Note that after this number of loop, the worker ends (the run method cannot be executed again)
The aim is to avoid memory leaks become too important.
terminate_gracefully
To avoid interrupting the execution of a job, if terminate_gracefully is set to True (the default), the SIGINT and SIGTERM signals are caught, asking the worker to exit when the current jog is done.
callback
The callback is the function to run when a job is fetched. By default it’s the execute method of the worker (which, if not overridden, raises a NotImplemented error) , but you can pass any function that accept a job and a queue as argument.
If this callback (or the execute method) raises an exception, the job is considered in error. In the other case, it’s considered successful and the return value is passed to the job_success method, to let you do what you want with it.
timeout
The timeout is used as parameter to the blpop redis command we use to fetch jobs from waiting lists. It’s 30 seconds by default but you can change it to any positive number (in seconds). You can set it to 0 if you don’t want any timeout be applied to the blpop command.
It’s better to always set a timeout, to reenter the main loop and call the must_stop method to see if the worker must exit. Note that the number of loops is not updated in the case of the timeout occurred, so a little timeout won’t alter the number of loops defined by max_loops.
fetch_priorities_delay
The fetch_priorities_delay is the delay between two fetches of the list of priorities for the current worker.
If a job was added with a priority that did not exist when the worker run was started, it will not be taken into account until this delay expires.
Note that if this delay is, say, 5 seconds (it’s 25 by default), and the timeout parameter is 30, you may wait 30 seconds before the new priority fetch because if there is no jobs in the priority queues actually managed by the worker, the time is in the redis hands.
Other worker’s attributes
In case on subclassing, you can need these attributes, created and defined during the use of the worker:
keys
A list of keys of queues waiting lists, which are listened by the worker for new jobs. Filled by the update_keys method.
status
The current status of the worker. None by default until the run method is called, after what it’s set to "starting" while getting for an available queue. Then it’s set to "waiting" while the worker waits for new jobs. When a job is fetched, the status is set to "running". And finally, when the loop is over, it’s set to "terminated".
If the status is not None, the run method cannot be called.
logger
The logger (from the logging python module) defined by the set_logger method.
num_loops
The number of loops done by the worker, incremented each time a job is fetched from a waiting list, even if the job is skipped (bad status…), or in error. When this number equals the max_loops attribute, the worker ends.
end_forced
When True, ask for the worker to terminate itself after executing the current job. It can be set to True manually, or when a SIGINT/SIGTERM signal is caught.
end_signal_caught
This boolean is set to True when a SIGINT/SIGTERM is caught (only if the terminate_gracefully is True)
connection
It’s a property, not an attribute, to get the current connection to the redis server.
Worker’s methods
As said before, the Worker class in spit in many little methods, to ease subclassing. Here is the list of public methods:
__init__
Signature:
def __init__(self, name=None, callback=None,
queue_model=None, job_model=None, error_model=None,
logger_base_name=None, logger_level=None, save_errors=None,
save_tracebacks=None, max_loops=None, terminate_gracefuly=None,
timeout=None, fetch_priorities_delay=None):
Returns nothing.
It’s the constructor (you guessed it ;) ) of the Worker class, excepting all arguments that can also be defined as class attributes.
It validates these arguments, prepares the logging and initializes other attributes.
You can override it to add, validate, initialize other arguments or attributes.
handle_end_signal
Signature:
def handle_end_signal(self):
Returns nothing.
It’s called in the constructor if terminate_gracefully is True. It plugs the SIGINT and SIGTERM signal to the catch_end_signal method.
You can override it to catch more signals or do some checked before plugging them to the catch_end_signal method.
stop_handling_end_signal
Signature:
def stop_handling_end_signal(self):
Returns nothing.
It’s called at the end of the run method, as we don’t need to catch the SIGINT and SIGTERM signals anymore. It’s useful when launching a worker in a python shell to finally let the shell handle these signals. Useless in a script because the script is finished when the run method exits.
set_logger
Signature:
def set_logger(self):
Returns nothing.
It’s called in the constructor to initialize the logger, using logger_base_name and logger_level, saving it in self.logger.
must_stop
Signature:
def must_stop(self):
Returns boolean.
It’s called on the main loop, to exit it on some conditions: an end signal was caught, the max_loops number was reached, or end_forced was set to True.
wait_for_job
Signature:
def wait_for_job(self):
Returns a tuple with a queue and a job
This method is called during the loop, to wait for an available job in the waiting lists. When one job is fetched, returns the queue (an instance of the model defined by queue_model) on which the job was found, and the job itself (an instance of the model defined by job_model).
get_job
Signature:
def get_job(self, job_pk):
Returns a job.
Called during wait_for_job to get a real job object (an instance of the model defined by job_model) based on the primary key fetched from the waiting lists.
get_queue
Signature:
def get_queue(self, queue_redis_key):
Returns a Queue.
Called during wait_for_job to get a real queue object (an instance of the model defined by queue_model) based on the key returned by redis telling us in which list the job was found. This key is not the primary key of the queue, but the redis key of it’s waiting field.
catch_end_signal
Signature:
def catch_end_signal(self, signum, frame):
Returns nothing.
It’s called when a SIGINT/SIGTERM signal is caught. It’s simply set end_signal_caught and end_forced to True, to tell the worker to terminate as soon as possible.
execute
Signature:
def execute(self, job, queue):
Returns nothing by default.
This method is called if no callback argument is provided when initiating the worker. But raises a NotImplementedError by default. To use it (without passing the callback argument), you must override it in your own subclass.
If the execution is successful, no return value is attended, but if any, it will be passed to the job_success method. And if an error occurred, an exception must be raised, which will be passed to the job_error method.
update_keys
Signature:
def update_keys(self):
Returns nothing.
Calling this method updates the internal keys attributes, which contains redis keys of the waiting lists of all queues listened by the worker (the ones with the same name).
It’s actually called at the beginning of the run method, and at intervals depending on fetch_priorities_delay. Note that if a queue with a specific priority doesn’t exist when this method is called, but later, by adding a job with add_job, the worker will ignore it unless this update_keys method was called again (programmatically or by waiting at least fetch_priorities_delay seconds)
run
Signature:
def run(self):
Returns nothing.
It’s the main method of the worker, with all the logic: while we don’t have to stop (result of the must_stop method), fetch a job from redis, and if this job is really in waiting state, execute it, and do something depending of the status of the execution (success, error…).
In addition to the methods that do real stuff (update_keys, wait_for_job), some other methods are called during the execution: run_started, run_ended, about the run, and job_skipped, job_started, job_success and job_error about jobs. You can override these methods in subclasses to adapt the behavior depending on your needs.
run_started
Signature:
def run_started(self):
Returns nothing.
This method is called in the run method after the keys are computed using update_keys, just before starting the loop. By default it does nothing but a log.info.
run_ended
Signature:
def run_ended(self):
Returns nothing.
This method is called just before exiting the run method. By default it does nothing but a log.info.
job_skipped
Signature:
def job_skipped(self, job, queue):
Returns nothing.
When a job is fetched in the run method, its status is checked. If it’s not STATUSES.WAITING, this job_skipped method is called, with two main arguments: the job and the queue in which it was found.
The only thing done is to log the message returned by the job_skipped_message method.
job_skipped_message
Signature:
def job_skipped_message(self, job, queue):
Returns a string to be logged in job_skipped.
job_started
Signature:
def job_started(self, job, queue):
Returns nothing.
When the job is fetched and its status verified (it must be STATUSES.WAITING), the job_started method is called, just before the callback (or the execute method if no callback is defined), with the job and the queue in which it was found.
This method updates the start and status fields of the job, then log the message returned by job_started_message.
job_started_message
Signature:
def job_started_message(self, job, queue):
Returns a string to be logged in job_started.
job_success
Signature:
def job_success(self, job, queue, job_result):
Returns nothing.
When the callback (or the execute method) is finished, without having raised any exception, the job is considered successful, and the job_success method is called, with the job and the queue in which it was found, and the return value of the callback method.
This method updates the end and status fields of the job, moves the job into the success list of the queue, then log the message returned by job_success_message.
job_success_message
Signature:
def job_success_message(self, job, queue, job_result):
Returns a string to be logged in job_success.
job_error
Signature:
def job_error(self, job, queue, exception, trace=None):
Returns nothing.
When the callback (or the execute method) is terminated by raising an exception, the job_error method is called, with the job and the queue in which it was found, and the raised exception and, if save_tracebacks is True, the traceback.
This method updates the end and status fields of the job, moves the job into the error list of the queue, adds a new error object (if save_errors is True), then log the message returned by job_error_message.
job_error_message
Signature:
def job_error_message(self, job, queue, exception):
Returns a string to be logged in job_error.
additional_error_fields
Signature:
def additional_error_fields(self, job, queue, exception, trace=None):
Returns a dictionary of fields to add to the error object, empty by default.
This method is called by job_error to let you define a dictionary of fields/values to add to the error object which will be created, if you use a subclass of the Error model, defined in error_model.
To pass these additional fields to the error object, you have to override this method in your own subclass.
id
It’s a property returning a string identifying the current worker, used in logging to distinct log entries for each worker.
log
Signature:
def log(self, message, level='info'):
Returns nothing.
log is a simple wrapper around self.logger, which automatically add the id of the worker at the beginning. It can accepts a level argument which is info by default.
set_status
Signature:
def set_status(self, status):
Returns nothing.
set_status simply update the worker’s status field.
count_waiting_jobs
Signature:
def count_waiting_jobs(self):
Returns the number of jobs in waiting state that can be run by this worker.
The worker.py script
To help using limpyd_jobs, an executable python script is provided: scripts/worker.py (usable as limpyd-jobs-worker, in your path, when installed from the package)
This script is highly configurable to help you launching workers without having to write a script or customize the one included.
With this script you don’t have to write a custom worker too, because all arguments attended by a worker can be passed as arguments to the script.
The script is based on a WorkerConfig class defined in limpyd_jobs.workers, that you can customize by subclassing it, and you can tell the script to use your class instead of the default one.
You can even pass one or many python paths to add to sys.path.
This script is designed to ease you as much as possible.
Instead of explaining all arguments, see below the result of the --help command for this script:
$ limpyd-jobs-worker --help Usage: limpyd-jobs-worker [options] Run a worker using redis-limpyd-jobs Options: --pythonpath=PYTHONPATH A directory to add to the Python path, e.g. --pythonpath=/my/module --worker-config=WORKER_CONFIG The worker config class to use, e.g. --worker- config=my.module.MyWorkerConfig, default to limpyd_jobs.workers.WorkerConfig --print-options Print options as parsed by the script, e.g. --print- options --dry-run Won't execute any job, just starts the worker and finish it immediatly, e.g. --dry-run --name=NAME Name of the Queues to handle e.g. --name=my-queue-name --job-model=JOB_MODEL Name of the Job model to use, e.g. --job- model=my.module.JobModel --queue-model=QUEUE_MODEL Name of the Queue model to use, e.g. --queue- model=my.module.QueueModel --errro-model=ERROR_MODEL Name of the Error model to use, e.g. --queue- model=my.module.ErrorModel --worker-class=WORKER_CLASS Name of the Worker class to use, e.g. --worker- class=my.module.WorkerClass --callback=CALLBACK The callback to call for each job, e.g. --worker- class=my.module.callback --logger-base-name=LOGGER_BASE_NAME The base name to use for logging, e.g. --logger-base- name="limpyd-jobs.%s" --logger-level=LOGGER_LEVEL The level to use for logging, e.g. --worker-class=INFO --save-errors Save job errors in the Error model, e.g. --save-errors --no-save-errors Do not save job errors in the Error model, e.g. --no- save-errors --save-tracebacks Save exception tracebacks on job error in the Error model, e.g. --save-tracebacks --no-save-tracebacks Do not save exception tracebacks on job error in the Error model, e.g. --no-save-tracebacks --max-loops=MAX_LOOPS Max number of jobs to run, e.g. --max-loops=100 --terminate-gracefuly Intercept SIGTERM and SIGINT signals to stop gracefuly, e.g. --terminate-gracefuly --no-terminate-gracefuly Do NOT intercept SIGTERM and SIGINT signals, so don't stop gracefuly, e.g. --no-terminate-gracefuly --timeout=TIMEOUT Max delay (seconds) to wait for a redis BLPOP call (0 for no timeout), e.g. --timeout=30 --fetch-priorities-delay=FETCH_PRIORITIES_DELAY Min delay (seconds) to wait before fetching new priority queues (>= timeout), e.g. --fetch-priorities-delay=30 --database=DATABASE Redis database to use (host:port:db), e.g. --database=localhost:6379:15 --no-title Do not update the title of the worker's process, e.g. --no-title --version show program's version number and exit -h, --help show this help message and exit
Except for --pythonpath, --worker-config, --print-options,--dry-run, --worker-class and --no-title, all options will be passed to the worker.
So, if you use the default models, the default worker with its default options, and to launch a worker to work on the queue queue-name, all you need to do is:
limpyd-jobs-worker --name=queue-name
We use the setproctitle module to display useful informations in the process name, to have stuff like this:
limpyd-jobs-worker#1566090 [init] queue=foo limpyd-jobs-worker#1566090 [starting] queue=foo loop=0/1000 waiting-jobs=10 limpyd-jobs-worker#1566090 [running] queue=foo loop=1/1000 waiting-jobs=9 limpyd-jobs-worker#1566090 [terminated] queue=foo loop=10/1000 waiting-jobs=0
You can disable it by passing the --no-title argument.
Final words
you can see a full example in example.py (in the source, not in the installed package)
to use limpyd_jobs models on your own redis database instead of the default one (localhost:6379:db=0), simply use the use_database method of the main model:
from limpyd.contrib.database import PipelineDatabase from limpyd_jobs.models import BaseJobsModel database = PipelineDatabase(host='localhost', port=6379, db=15) BaseJobsModel.use_database(database)
or simply change the connection settings:
from limpyd_jobs.models import BaseJobsModel BaseJobsModel.database.connect(host='localhost', port=6379, db=15)
The end.
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