SharQ
SharQ is a flexible rate limited queueing system built using Redis. SharQ is the core library that powers the SharQ Server.
Installation
- Install the latest stable release of Redis.
- Install SharQ using pip
pip install sharq
Configuration
Sample SharQ Config file.
[sharq]
job_expire_interval : 1000 ; in milliseconds
job_requeue_interval : 1000 ; in milliseconds
default_job_requeue_limit : -1 ; retries infinitely
[redis]
db : 0
key_prefix : sharq_server
conn_type : tcp_sock ; or unix_sock
;; unix connection settings
unix_socket_path : /tmp/redis.sock
;; tcp connection settings
port : 6379
host : 127.0.0.1
clustered : false
Note: Uncomment the following lines in your redis.conf if you are using unix socket to connect to Redis.
unixsocket /var/run/redis/redis.sock
unixsocketperm 755
Usage
Initialization
>>> from sharq import SharQ
>>> sq = SharQ('/path/to/config/sharq.conf')Enqueue
Enqueues a job into the queue. Every enqueue request is accompanied with an interval. The interval specifies the rate limiting capability of SharQ. An interval of 1000ms implies that SharQ will ensure two successful dequeue requests will be separated by 1000ms (interval is the inverse of rate. 1000ms interval means 1 job per second)
>>> response = sq.enqueue(
job_id='cea84623-be35-4368-90fa-7736570dabc4',
payload={'message': 'hello, world'},
interval=1000, # in milliseconds.
queue_id='user001',
queue_type='sms' # optional. defaults to 'default' queue type.
)
>>> print response
{'status': 'queued'}Dequeue
Dequeues a job (non-blocking). It returns a job only if available or if it is ready for dequeue (based on the interval set while enqueueing).
>>> response = sq.dequeue(
queue_type='sms' # optional.
)
>>> print response # when the queue is empty or no job is ready.
{'status': 'failure'}
>>> print response # when the job is ready.
{'job_id': 'cea84623-be35-4368-90fa-7736570dabc4',
'payload': {'message': 'hello, world'},
'queue_id': 'johndoe',
'status': 'success'}Finish
Marks any dequeued job as succesfully completed. Any job which does get marked as finished upon dequeue will be re-enqueued into its respective queue after an expiry time (the job_requeue_interval in the config).
>>> response = sq.finish(
queue_type='sms',
job_id='bb59a2be-3b48-4645-8134-d9181742e3cf',
queue_id='user001'
)
>>> print response
{'status': 'success'}Requeue
Ee-queues all the jobs which do not get the finish (ACK) within the expiry time (the job_requeue_interval in the config file).
>>> response = sq.requeue() # re-queues all expired jobs.
>>> print response
NoneInterval
Updates the interval for a specified queue on the fly. The interval specifies the rate limiting capability of SharQ. An interval of 1000ms implies that SharQ will ensure two successful dequeue requests will be separated by 1000ms (interval is the inverse of rate. 1000ms interval means 1 job per second).
>>> response = sq.interval(
queue_type='sms',
interval=5000, # interval between two successful dequeues is set to 5s
queue_id='user001'
)
>>> print response
{'status': 'success'}Metrics
Gets the SharQ metrics like,
- Overall enqueue / dequeue rate.
- Queue specific enqueue / dequeue rate.
- Queue types and queue ids in SharQ.
- Queue length of a particual queue.
>>> response = sq.metrics() # gets the overall statistics.
>>> print response
{'dequeue_counts': {
'1406280420000': 10, # epoch timestamp of the minute & the dequeue count.
'1406280480000': 0,
'1406280540000': 304,
'1406280600000': 0,
'1406280660000': 605,
'1406280720000': 604,
'1406280780000': 615,
'1406280840000': 233,
'1406280900000': 322,
'1406280960000': 272},
'enqueue_counts': {
'1406280420000': 0,
'1406280480000': 0,
'1406280540000': 0,
'1406280600000': 0,
'1406280660000': 0,
'1406280720000': 0,
'1406280780000': 40,
'1406280840000': 40,
'1406280900000': 40,
'1406280960000': 39},
'queue_types': ['sms'],
'status': u'success'}
>>> response = sq.metrics(queue_type='sms') # gets the queue ids of this type.
>>> print response
{'queue_ids': ['user001', 'user002'], 'status': 'success'}
>>> response = sq.metrics( # gets the stats for this particular queue.
queue_type='sms',
queue_id='user001'
)
>>> print response
{'dequeue_counts': {
'1406280420000': 10, # epoch timestamp of the minute & the dequeue count.
'1406280480000': 0,
'1406280540000': 304,
'1406280600000': 0,
'1406280660000': 605,
'1406280720000': 604,
'1406280780000': 615,
'1406280840000': 233,
'1406280900000': 322,
'1406280960000': 272},
'enqueue_counts': {
'1406280420000': 0,
'1406280480000': 0,
'1406280540000': 0,
'1406280600000': 0,
'1406280660000': 0,
'1406280720000': 0,
'1406280780000': 40,
'1406280840000': 40,
'1406280900000': 40,
'1406280960000': 39},
'queue_length': 2400, # the number of jobs in this queue.
'status': u'success'}Development
Getting the source code
git clone https://github.com/plivo/sharq.git
Running Tests
make test
Building a Package
make build
Install / Uninstall
make install
make uninstall
License
The MIT License (MIT)
Copyright (c) 2014 Plivo Inc
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
