throttle

class naz.throttle.BaseThrottleHandler

Bases: abc.ABC

This is the interface that must be implemented to satisfy naz’s throttle handling. User implementations should inherit this class and implement the throttled, not_throttled, allow_request and throttle_delay methods with the type signatures shown.

When an SMPP client exceeds it’s rate limit, or when the SMSC is under load or for whatever reason; The SMSC may decide to start throtlling requests from that particular client. When it does so, it replies to the client with a throttling status. Under such conditions, it is important for the client to start rate limiting itself. The way naz implements this self imposed self-regulation is via Throttle Handlers.

The methods in this class are also called when the SMSC is under load and is responding with `ESME_RMSGQFUL`(message queue full) responses

abstract async allow_request()

this method will be called by naz just before sending a request to SMSC. The response from this method will determine wether naz will send the request or not.

Return type

bool

abstract async not_throttled()

this method will be called by naz everytime we get any response from SMSC that is not a throttling response.

Return type

None

abstract async throttle_delay()

if the last allow_request method call returned False(thus denying sending a request), naz will call the throttle_delay method to determine how long in seconds to wait before calling allow_request again.

Return type

float

abstract async throttled()

this method will be called by naz everytime we get a throttling response from SMSC.

Return type

None

class naz.throttle.SimpleThrottleHandler(sampling_period=180.0, sample_size=50.0, deny_request_at=1.0, throttle_wait=3.0, logger=None)

Bases: naz.throttle.BaseThrottleHandler

This is an implementation of BaseThrottleHandler.

It works by:

• calculating the percentage of responses from the SMSC that are THROTTLING(or ESME_RMSGQFUL) responses.

• if that percentage goes above deny_request_at percent AND total number of responses from SMSC is greater than sample_size over sampling_period seconds

• then deny making anymore requests to SMSC

__init__(sampling_period=180.0, sample_size=50.0, deny_request_at=1.0, throttle_wait=3.0, logger=None)

Parameters

• sampling_period (float) – the duration in seconds over which we will calculate the percentage of throttled responses.

• sample_size (float) – the minimum number of responses we should have got from SMSC over :sampling_period duration to enable us make a decision.

• deny_request_at (float) – the percent of throtlled responses above which we will deny naz from sending more requests to SMSC.

• throttle_wait (float) – the time in seconds to wait before calling allow_request after the last allow_request that returned False.

Return type

None

async allow_request()

this method will be called by naz just before sending a request to SMSC. The response from this method will determine wether naz will send the request or not.

Return type

bool

async not_throttled()

this method will be called by naz everytime we get any response from SMSC that is not a throttling response.

Return type

None

async throttle_delay()

if the last allow_request method call returned False(thus denying sending a request), naz will call the throttle_delay method to determine how long in seconds to wait before calling allow_request again.

Return type

float

async throttled()

this method will be called by naz everytime we get a throttling response from SMSC.

Return type

None