Subscribe to Timer Events

Function Description

After you subscribe to timer events and a timer event is triggered, the system executes the ops_execute() function in the Python script.

This API can only be used in the ops_condition() function of the maintenance assistant script.

Command Prototype

# Timer event defined in the Linux cron timer description format

opsObj.timer.cron(tag, crontime)

# Cyclic timer, triggered at a specified interval

opsObj.timer.relative(tag, timelength)

# Timer triggered after a specified number of seconds elapses since zero hour of the year of 1970

opsObj.timer.absolute(tag, timelength)

# Timer triggered after a specified number of seconds elapses since a timer event is subscribed

opsObj.timer.countdown(tag, timelength)

Parameter Description

Table 1 describes parameters supported by timer event subscription APIs.

**Table 1** Parameters supported by timer event subscription APIs
Method	Description
opsObj	Specifies an OPS object. It is obtained through ops.ops() instantiation.
tag	Specifies a condition ID. The value is a string of 1 to 8 case-sensitive characters that starts with a letter and contains letters, digits, and underscores (_). Enter double quotation marks ("") or None for the only one condition. tag cannot be set to and, or, or not.
crontime	Specifies a cron timer description. The value is a character string. For example, * * * * * indicates that the timer is triggered every second.
timelength	Specifies a timer value, in seconds.

Description of Return Values

First return value: The value 0 indicates a success, and the value 1 indicates a failure.
Second return value: This value describes success or failure reasons, expressed in a character string.

Example

test.py

import ops

def ops_condition(_ops):
    _ops.timer.countdown("con11", 5)
    _ops.correlate("con11")

def ops_execute(_ops):
    _ops.syslog("Record an informational syslog.")
    return 0

A timer event is triggered 5s after the timer event is subscribed.