15. WalBvs DRBD
WalB
Method to detect diffs
WAL
DRBD
Bitmaps
Penalty
after crash
Redo
Additional
data transfer
Snapshot
reproduction
capability
Yes
No
Write amount
on devices
2x+
1x+
15
17. 逐次処理した場合のIO処理の流れ
•SubmittedからCompletedまでが長い
Submitted
Time
Completed
Packed
Log submitted
Log completed
Wait for log Flushed and overlapped IOs done
Data submitted
Data completed
Write
Submitted
Time
Completed
Data submitted
Data completed
Read
Log IO response
Data IO response
Write IO response
Data IO response
17
18. WalBのIO処理の流れ
•SubmittedからCompletedまでが短い
Submitted
Time
Completed
Packed
Log submitted
Log completed
Wait for log Flushed and overlapped IOs done
Data submitted
Data completed
Log IO response
Data IO response
WalBwrite IO response
Pdatainserted
Pdatadeleted
Write
Submitted
Time
Completed
(Data submitted)
(Data completed)
Read
Pdatacopied
Data IO response
18
29. HDD 単体での性能(IOPS)
Write-once
dm-thinp/cow
26515
Random write
4404/3856
11008
Sequential read
---/34816
181
Random read
---/143
Virtual disk size: 4GiB
Number of 4KiBrandom writes: 1M
Number of diffs: 32
29
30. SSD 単体での性能(IOPS)
Write-once
dm-thinp/cow
16711
Random write
17980/9989
53760
Sequential read
---/36352
1657
Random read
---/4630
Virtual disk size: 4GiB
Number of 4KiBrandom writes: 1M
Number of diffs: 32
30
31. RAID6: Random Write
Virtual disk size: 16GiB
Number of 4KiBrandom writes: 16M
Number of diffs: 16-16384 31
32. RAID6: Sequential Read
Virtual disk size: 16GiB
Number of 4KiBrandom writes: 16M
Number of diffs: 16-16384 32
33. RAID6: Random Read
Virtual disk size: 16GiB
Number of 4KiBrandom writes: 16M
Number of diffs: 16-16384 33