Symptoms

SLA Notifications / e-mails are being sent at incorrect percentages (e.g. "INC0100000 has reached 77.19% of its SLA" instead of the expected "INC0100000 has reached 75% of its SLA")

Release

Istanbul Patch 11a

Cause

This is working as expected (see further explanation below...)

Resolution

The user's custom "Notification - SLA warning" was imported into an Out of Box (OOB) instance and the behavior mentioned in the above "Symptoms" field was reproduced there.

It is worth noting that the user's configuration is not the same as the OOB "Notification - SLA warning". OOB we do not use "$(percentage)" - presumably to avoid this undesirable/unexpected behavior.

After importing the user's custom notification, if an incident with some task_sla attached to it is created, e-mails are being generated showing various percentages other than 50, 75, and 100%. 

Here are the e-mail percentages received from the example incident test:
50% notification: 54.44% 
75% notification: 75.56%
100% notification: 102.78%

Rather than using $(percentage) and receiving uneven percentages (which is expected behavior OOB), suggest that the user implement a general warning as seen in the OOB "Notification - SLA warning", such as: 

Subject: SLA warning for ${task.number}

Message/body: 

SLA warning for ${task.number}:

SLA definition Name: ${sla.name}
Task State: ${task.state}
Task Opened: ${task.opened_at}
Task Priority: ${task.priority}
Task Assignment Group: ${task.assignment_group}
Task Assigned To: ${task.assigned_to}
Task Short Description: ${task.short_description}