Hi,
I'm testing multistreaming backup/recovery with backint and SPS11. The test DB I have is 180GB
It is working fine for backups. I set parallel_data_backup_backint_channels to something like 4 or 8 and Hana creates that number of backint streams. I have of course configured my backup tool to accept this number of channels.
But for recovery, hana only creates one channel and restores each part in sequence.
In this example, backup takes 6 minutes, but restore takes close to an hour.
Backup excerpt:
2016-03-31T09:19:07+02:00 P001993 153cb8a1153 INFO BACKUP SAVE DATA will write to the following files :
…
2016-03-31T09:19:07+02:00 P001993 153cb8a1153 INFO BACKUP to backint: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_1
2016-03-31T09:19:07+02:00 P001993 153cb8a1153 INFO BACKUP to backint: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_2
2016-03-31T09:19:07+02:00 P001993 153cb8a1153 INFO BACKUP to backint: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_3
2016-03-31T09:19:07+02:00 P001993 153cb8a1153 INFO BACKUP to backint: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_4
…
2016-03-31T09:19:12+02:00 P001993 153cb8a1153 INFO BACKUP progress of service: indexserver, testsrv2:38803, volume: 3, 0% 0/193743294464
…
2016-03-31T09:25:06+02:00 P001993 153cb8a1153 INFO BACKUP progress of service: indexserver, testsrv2:38803, volume: 3, 100% 193743290368/193743290368
Recovery excerpt:
2016-04-12T17:33:01+02:00 P020130 1540b19e8af INFO RECOVERY using file: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_1 EBID: USB___A0IMFYAD5O
2016-04-12T17:33:01+02:00 P020130 1540b19e8af INFO RECOVERY progress of service: indexserver, testsrv2:38803, volume: 3, 0% 0/193743294464
…
2016-04-12T17:50:10+02:00 P020130 1540b19e8af INFO RECOVERY using file: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_2 EBID: USB___A0IMFYAD5O
2016-04-12T17:50:10+02:00 P020130 1540b19e8af INFO RECOVERY progress of service: indexserver, testsrv2:38803, volume: 3, 25% 48435822592/193743290368
…
2016-04-12T18:03:20+02:00 P020130 1540b19e8af INFO RECOVERY using file: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_3 EBID: USB___A0IMFYAD5O
2016-04-12T18:03:20+02:00 P020130 1540b19e8af INFO RECOVERY progress of service: indexserver, testsrv2:38803, volume: 3, 50% 96871645184/193743290368
…
2016-04-12T18:15:27+02:00 P020130 1540b19e8af INFO RECOVERY using file: /usr/sap/USB/SYS/global/hdb/backint/BI-4_databackup_3_4 EBID: USB___A0IMFYAD5O
2016-04-12T18:15:27+02:00 P020130 1540b19e8af INFO RECOVERY progress of service: indexserver, testsrv2:38803, volume: 3, 75% 145307467776/193743290368
…
2016-04-12T18:26:09+02:00 P020130 1540b19e8af INFO RECOVERY progress of service: indexserver, testsrv2:38803, volume: 3, 100% 193743290368/193743290368
The restore log shows clearly that the backup parts are processed in sequence, not in parallel.
I also see in the backup tool that no parallel sessions are created when restoring.
Is this behaviour by design? I expect Hana to restore the streams in parallel, just as the backup.
thanks,
Robert