drgreen/android_frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Use setRepeating() rather than setInexactRepeating() for backup scheduling,

Browse Source 
and add some random fuzz to the scheduling times, to make sure we aren't
creating hour-aligned server load spikes.

See bug 2226553 for details & Dr. No information.
This commit is contained in:
Dan Egnor
2009-10-30 17:35:39 -07:00
parent 824838d74e
commit c1c49c024f
1 changed files with 13 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
services/java/com/android/server/BackupManagerService.java
View File

@ -76,6 +76,7 @@ import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Random;
class BackupManagerService extends IBackupManager.Stub {
private static final String TAG = "BackupManagerService";
@ -85,6 +86,9 @@ class BackupManagerService extends IBackupManager.Stub {
// trigger an immediate pass.
private static final long BACKUP_INTERVAL = AlarmManager.INTERVAL_HOUR;
// Random variation in backup scheduling time to avoid server load spikes
private static final int FUZZ_MILLIS = 5 * 60 * 1000;
// The amount of time between the initial provisioning of the device and
// the first backup pass.
private static final long FIRST_BACKUP_INTERVAL = 12 * AlarmManager.INTERVAL_HOUR;
@ -1949,9 +1953,15 @@ class BackupManagerService extends IBackupManager.Stub {
}
private void startBackupAlarmsLocked(long delayBeforeFirstBackup) {
long when = System.currentTimeMillis() + delayBeforeFirstBackup;
mAlarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, when,
BACKUP_INTERVAL, mRunBackupIntent);
// We used to use setInexactRepeating(), but that may be linked to
// backups running at :00 more often than not, creating load spikes.
// Schedule at an exact time for now, and also add a bit of "fuzz".
Random random = new Random();
long when = System.currentTimeMillis() + delayBeforeFirstBackup +
random.nextInt(FUZZ_MILLIS);
mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP, when,
BACKUP_INTERVAL + random.nextInt(FUZZ_MILLIS), mRunBackupIntent);
mNextBackupPass = when;
}