tensor

tensor.aggregators

tensor.aggregators.Counter(a, b, delta)

Counter derivative

tensor.aggregators.Counter32(a, b, delta)

32bit counter aggregator with wrapping

tensor.aggregators.Counter64(a, b, delta)

64bit counter aggregator with wrapping

tensor.interfaces

tensor.objects

class tensor.objects.Event(state, service, description, metric, ttl, tags=None, hostname=None, aggregation=None, evtime=None, attributes=None, type='riemann')

Bases: object

Tensor Event object

All sources pass these to the queue, which form a proxy object to create protobuf Event objects

Parameters:

• state – Some sort of string < 255 chars describing the state
• service – The service name for this event
• description – A description for the event, ie. “My house is on fire!”
• metric – int or float metric for this event
• ttl – TTL (time-to-live) for this event
• tags – List of tag strings
• hostname – Hostname for the event (defaults to system fqdn)
• aggregation – Aggregation function
• attributes – A dictionary of key/value attributes for this event
• evtime – Event timestamp override

class tensor.objects.Output(config, tensor)

Bases: object

Output parent class

Outputs can inherit this object which provides a construct for a working output

Parameters:

• config – Dictionary config for this queue (usually read from the yaml configuration)
• tensor – A TensorService object for interacting with the queue manager

createClient()

Deferred which sets up the output

eventsReceived()

Receives a list of events and processes them

Arguments: events – list of tensor.objects.Event

stop()

Called when the service shuts down

class tensor.objects.Source(config, queueBack, tensor)

Bases: object

Source parent class

Sources can inherit this object which provides a number of utility methods.

Parameters:

• config – Dictionary config for this queue (usually read from the yaml configuration)
• queueBack – A callback method to recieve a list of Event objects
• tensor – A TensorService object for interacting with the queue manager

createEvent(state, description, metric, prefix=None, hostname=None, aggregation=None, evtime=None)

Creates an Event object from the Source configuration

createLog(type, data, evtime=None, hostname=None)

Creates an Event object from the Source configuration

startTimer()

Starts the timer for this source

stopTimer()

Stops the timer for this source

tick(*args, **kwargs)

Called for every timer tick. Calls self.get which can be a deferred and passes that result back to the queueBack method

Returns a deferred

tensor.service

class tensor.service.TensorService(config)

Bases: twisted.application.service.Service

Tensor service

Runs timers, configures sources and and manages the queue

sendEvent(source, events)

Callback that all event sources call when they have a new event or list of events

setupOutputs(config)

Setup output processors

setupSources(config)

Sets up source objects from the given config

sourceWatchdog()

Watchdog timer function.

Recreates sources which have not generated events in 10*interval if they have watchdog set to true in their configuration

tensor.utils

class tensor.utils.BodyReceiver(finished)

Bases: twisted.internet.protocol.Protocol

Simple buffering consumer for body objects

class tensor.utils.PersistentCache(location='/var/lib/tensor/cache')

Bases: object

A very basic dictionary cache abstraction. Not to be used for large amounts of data or high concurrency

contains(k)

Return True if key k exists

delete(k)

Remove key k from the cache

expire(age)

Expire any items in the cache older than age seconds

get(k)

Returns key contents, and modify time

set(k, v)

Set a key k to value v

class tensor.utils.ProcessProtocol(deferred, timeout)

Bases: twisted.internet.protocol.ProcessProtocol

ProcessProtocol which supports timeouts

class tensor.utils.Resolver

Bases: object

Helper class for DNS resolution

class tensor.utils.StringProducer(body)

Bases: object

String producer for writing to HTTP requests

exception tensor.utils.Timeout

Bases: exceptions.Exception

Raised to notify that an operation exceeded its timeout.

tensor.utils.fork(executable, args=(), env={}, path=None, timeout=3600)

Provides a deferred wrapper function with a timeout function

Parameters:

• executable (str.) – Executable
• args (tupple.) – Tupple of arguments
• env (dict.) – Environment dictionary
• timeout (int.) – Kill the child process if timeout is exceeded