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<concept id="GUID-00363030-AAE2-5231-8407-AC609DA0F496" xml:lang="en"><title>Backup

and Restore on Scheduled Tasks in Persistent Schedules</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>When scheduling tasks in persistent schedules, special consideration must

be given to the effects of backup and restore operations. Persistent schedules

and tasks associated with them are backed up during a backup operation. This

results in the storage of their status at the time of backup. When the data

is restored on the same phone or another phone, the persistent scheduled tasks

are recreated. This results in the overwrite of any existing persistent schedule

and task on the phone. </p>

<p> <b>Note:</b> Transient schedule and tasks are affected by the backup or

restore process. </p>

<section><title>Impact of backup and restore on persistent schedules and tasks</title> <p>State

information associated with a phone, such as date, time and conditions are

not backed up with schedules and tasks, during a phone backup. The date or

time of a phone at the time of a backup is always likely to be different from

the date or time of the target phone during restore. The conditions that are

based on <xref href="GUID-C4776034-D190-3FC4-AF45-C7F195093AC3.dita"><apiname>RProperty</apiname></xref> values that indicate the various states

of a phone might also be different between the time of backup and the time

of restore. One example is the network status, which may be unavailable at

the time of backup, but available at the time of restore. </p> <p><b>Possible

problems</b> </p> <p>When a task is scheduled in a persistent schedule, its

execution depends on a specific time or condition to become due. If the phone

is backed up before the schedule is due, the schedule information is also

part of the backup. Later, when the time or condition is satisfied, the task

is executed on the phone. But, when a phone restore is done after the task

is executed on the phone, the schedule may be due again and the task may get

executed, if the same time or condition is satisfied again. </p> <p>For example,

assume that a condition-based task is created to send an SMS when the network

is available. In addition, assume that when this task is created the network

is unavailable and a phone backup is taken. After the backup, the phone network

may become available and the SMS may be sent. In this scenario, when a phone

restore is done the SMS may be sent again when the network is available, which

can result in additional SMS costs. </p> <p><b>Recommended alternatives</b> </p> <p>The

non-repeatable nature of the tasks cannot be determined by the task scheduler

automatically, and there is no mechanism for setting per-schedule backup options.

For this reason, clients that create non-repeatable tasks must be aware of

backup and restore implications and consider this fact in their designs. </p> <p>Clients

can use transient schedules for non-repeatable tasks, which eliminates this

problem because transient schedules are not backed up or restored. If the

use of a persistent schedule is necessary, clients can choose to become backup-aware

by registering for notifications through <xref href="GUID-DC57CA2E-0EDF-3AF2-BC65-50D71665333B.dita"><apiname>CBaBackupSessionWrapper</apiname></xref> or

using the <xref href="GUID-0FE60A65-6CB6-50AB-B85F-2B60FE96ECFE.dita">Secure Backup

Engine</xref> APIs, and taking appropriate actions. These actions might be

to delete the non-repeatable task before backup or after restore, or rescheduling

it after restore to a different time for time-based schedules. </p> <p> <b>Note:</b> Any

schedule that expires or becomes ready to execute when a backup or restore

is in progress is delayed, and is only executed when the backup or restore

process is completed. </p> </section>

</conbody><related-links>

<link href="GUID-3CDCE4E0-E29D-5782-8053-B386A9E34BCC.dita"><linktext>Task Scheduler

Overview</linktext></link>

<link href="GUID-74C1C345-823C-5CD5-8FC5-214A55734E94.dita"><linktext>Developing

Programs with Task Scheduling Capabilities</linktext></link>