This document summarizes a presentation given at SC11 about monitoring power usage of a Google data center using sensors connected to an embedded Linux board. Data was sent to Google App Engine (GAE) using a REST API and retrieved for display. The system monitored up to 32 power circuits with 1 second resolution and was demonstrated at the NICT booth.

1. 2011 11 29 OS/EMB

2. •
•
–
– REST API
•
– SC11
•
2

3. •
–
– Google data center in the Dalles, Oregon
• 3 11
Fukushima Daiichi Nuclear Power Plant
3

4. •
•
•
4

5. •
• ISP
5

6. •
•
–
– REST API
•
– SC11
•
6

7. 2
…
…
3
Update power usage Google App Engine
using REST w/ JSON
Retrieve data using
REST w/ JSON
Alert
4 Viewer
1
7

8. •
• 4 1
•
Clamp-on current sensor (max: 4)
RJ-45 port
Signal processing board
(dsPIC30F3013)
8

9. /
•
• 32
– UTP
• 20 GAE push
– NAT
•
32 GAE
9

10. /
GAE
RJ-45 ports x 32
CPU T-SH7706LSR
- SH3 Linux
- Buildroot 2011.05
- pmon.py
Xilinx Spartan-3E
10

11. Google App Engine
• Web PaaS
– Java Python Go
•
– 5
– 2
•
–
•
–
11

12. •
– 1 PowerMinite
• update
– 1 PowerHour
• GAE
– 1 PowerDay
• 1 cron
• Google App Engine for Java MVC
Slim3
12

13. Small start Go big
Google App Engine
Datastore
4
32
= 128
•
• GAE
...
13

14. less than 90% of the upper limit
less than 95% of the upper limit
more than 95% of the upper limit
Offline
HTML5
14

15. REST API
path
method
description
/update
POST
/latest
GET
1
/latest,N
GET
N
/summary.s/YYYYmmDDHHMMSS,N
GET
N
/summary.m/YYYYmmDDHHMM,N
GET
N
/summary.h/YYYYmmDDHH,N
GET
N
/summary.d/YYYYmmDD,N
GET
N
/query.s/LOC/YYYYmmDDHHMMSS,N
GET
LOC N
/query.m/LOC/YYYYmmDDHHMM,N
GET
/unit-config/UNIT_ID
GET
/unit-config/UNIT_ID
PUT
15

16. 20 GAE
xxx.appspot.com/update
GAE
POST JSON
{
"id": ”UNIT_ID"
"time": "1319837460” /* elapsed seconds from the UNIX epoch time */
"power": { /* data for the last 20 seconds per measurement point */
"sensor0.0": [VAL0, VAL1, VAL2, VA3, ..., VAL19],
"sensor0.1": [VAL0, VAL1, VAL2, VA3, ..., VAL19],
"sensor1.0": [VAL0, VAL1, VAL2, VA3, ..., VAL19],
....
}
}
16

17. 1 GAE
xxx.appspot.com/latest,N
GAE
GET JSON
{
"time": “1319837460” /* epoch time */
"timeStr": “201110290631” /* human readable
time in JST */
"power": {
"LOCATION0": [1234]
"LOCATION1": [1234]
"LOCATION2": [1234]
"LOCATION3": [1234]
"LOCATION4": [1234]
...
} Viewer application
}
17

18. •
•
–
– REST API
•
– SC11
•
18

19. SC11
AIST (JP)
11 14 17
7
82
290 1
2
1 …
3
…
2 Google App Engine
Update power usage
using REST w/ JSON
Retrieve data using
REST w/ JSON
NICT booth #4717(US)
2 3
Viewer
1 Viewer
2
3 AIST booth #917(US)
19

20. 2011 8
GAE
20

21. NICT
NICT
x2
Tiled display wall
server
Juniper’s routers
GAE
21

22. SC11 NICT
22

23. /
• GAE
– 4 GAE
–
• 0.75 / 5KB/
• 500MB
–
•
– 30
–
23

24. /
• config
– SC11
– config
•
• config
24

25. •
•
–
– REST API
•
– SC11
•
25

26. •
3
– 290
– SC11
•
•
–
–
26

27. Q&A
27

28. GAE
0.75 HTTP requests/second
5000 bytes received/second
28