INF5100 Mandatory Exercise. Autumn 2009

Transcription

1 INF5100 Mandatory Exercise Autumn 2009

2 Contents Important notes Team structure About the mandatory exercise Part I Part II

3 Important notes Due: Wednesday November 4th 2009 at 16:00 Deliver by to Jarle (jarleso at ifi.uio.no) If needed: installation/run procedures (explain) See also delivery instructions for Part I Read through guidelines for written assignments

4 Team structure Max 2 students in each team Team member names and adresses to Jarle (jarleso at ifi.uio.no). before midnight September 15th (Tuesday). Those who haven t got a group by the 15th will be randomly assigned to a group Requests for group of 1 person need a good reason! to Jarle (jarleso at ifi.uio.no) before midnight September 9th (Wed).

5 About the mandatory exercise The exercise consists of two parts Part I: TinyDB Part II: PostgreSQL SQL queries All parts and exercises must be solved. Language: English or Norwegian

6 Part I: TinyDB Practical usage of the emulator and the real motes

7 Outline Overview TinyDB TinyOS and limitations The assignment Lab setup and practical information

8 Overview Understanding usage of declarative languages for querying sensors Use an ordinary DBMS to extract even more information Discuss possible optimizations

9 Overview Each group has its own user on dmms-lab107.ifi.uio.no Login from Linux with options XY Login from Windows: Make sure to enable X11 forwarding Each group has one instance of TinyOS TinyDB PostgreSQL Avrora WSN emulator The last three are explicitly used in the assignment

10 Overview We use both an emulator and real motes The emulator is for testing and making sure things are all right and confirming that the results are correct Each group will receive a time slot where the real experiments on the motes are performed The fewer groups, the longer time to work on the real motes, thus groups of two persons is recommended for all

11 TinyOS Is located in tinyos-1.x/ in your group s folder Contains the files and libraries used by TinyDB (and other programs) All TinyOS programs on the motes are written in nesc and compiled on the base station (BS) before distributed to the motes Please look at the code if you re interested

12 TinyDB A small DSMS written for WSNs Needs a root node, which is connected to a stationary, i.e. connected to a power outlet, computer The root mote is node 0 Creates a tree to the other motes Handles all distribution of the queries Has a simple and intuitive interface Can log the result tuples to a PostgreSQL database

13 TinyDB s startup picture

14 TinyDB The query is stated by pressing the buttons, and the resulting query shows up Check the Log to Database field to log all the arriving tuples to PostgreSQL Press Send Query and a result window appears Get known to the system by trying the different buttons, but

15 TinyDB - Limitations TinyDB has limited expression strength Only some parts are implemented in the version we are currently using Windowing is not supported, i.e., results do not appear even though the query executor doesn t complain, and so on Sometimes you have to resend queries if results do not appear The running time of the query can not be set We cannot really use TinyDB optimally: It is a research project with code made just for showing concepts The examples in the TinyDB slides are not working since they have slightly different syntax than for the TinyDB prototype

16 TinyDB In the assignment, we should use PostgreSQL to perform some post analyses of the tuples Analysis of the data Stored as tuples in the database Start the PostgreSQL client at your group s login domain at dmms-lab107.ifi.uio.no by writing mypsql Make sure the postmaster server is running: ps ax grep postmaster If not, start it by writing pg_ctl start l /tmp/inf5100- <your group #>_logfile and then write mypsql Check out the table called queries The result tuples are stored there if Log to Database is marked in the TinyDB interface (see slide 13)

17 TinySQL These are the TinySQL clauses that you should need: SELECT <aggregates>, <attributes> [FROM {sensors}] [WHERE <predicates>] [GROUP BY <exprs>] [HAVING <aggregate>] [SAMPLE PERIOD <const> ONCE]

18 The Sensor Network Assignment Tasks 1. Measure the light for 60 seconds with a preferred sample interval. Argue why you use this sample interval. Remember to log to the database. 2. What is the total average of these readings? 3. Use these readings to measure only those readings having a value less than the total average. Run test for 60 seconds with the preferred sample interval. 4. Are there any difference in the results from the emulator and the motes? Why/Why not? 5. What is the difference between a central and a distributed implementation of the HAVING clause for aggregations like SUM and MAX? How does this affect the power consumption? Discuss and give examples. 6. Discuss some of the differences between the theoretical and practical experience with TinyDB.

19 Delivery of the sensor network part of the INF5100 assignment The result should be a document Discuss/show the queries and plots of the results for task 1 3 Discuss the results, do not assume the reader understands the results from the plots End up with a nice discussion on task 4 6 (0.5 to 1 page per question). Show that you understand. Also deliver your data and the document packet tarred and (g)zipped

20 Lab Setup The Mica2 motes 0 1 2

21 Running TinyDB with emulator 1. The Avrora WSN emulator Open a new window at dmms-lab107.ifi.uio.no > avrora 2. The serial forwarder 3. TinyDB Open a new window at dmms-lab107.ifi.uio.no > sf Open a new window at dmms-lab107.ifi.uio.no Uncomment comm-string:sf@localhost$900n (N depends on the group, e.g. group INF has 9002) in tinyos- 1.x/tools/java/net/tinyos/tinydb/tinydb.co nf > tinydb

22 Running TinyDB for real Comment (N depends on the group) in tinyos-1.x/tools/java/net/tinyos/tinydb/tinydb.conf Uncomment in tinyos- 1.x/tools/java/net/tinyos/tinydb/tinydb.conf > tinydb

23 Lab Setup The three motes are located in the DMMS lab The experiments on the motes can start in the beginning of October Use the emulator for so long Solve the other two parts of the assignment A schedule for access to the real motes is presented in heim.ifi.uio.no/~jarleso/inf5100/schedule.html and is ready when the groups are registered The schedule is tight, but everything (queries) should be ready when you can access the motes

24 Practical information Initially, the password for each group is equal to the group name, i.e., INF5100-5, for example Wait to log in before you know which group you are on

25 Practical Information To get data from PostgreSQL to a file, write mypsql -q -F ',' -A -t c <query> o <result file> Use your favorite plotting program to create the plots Use your favorite document creation program to write the text But the delivered document must be in pdf. Send me an if you experience some practical challenges A FAQ is located at heim.ifi.uio.no/~jarleso/inf5100/faq/ I add Q&As there, if the question is not too way out

26 Part II PostgreSQL SQL queries

27 PostgreSQL SQL queries A set of 4 queries to be solved using SQL against the PostgreSQL implementation The PostgreSQL used for Part II can be accessed from an Ifi login machine Report SQL query and answers (write comments/explain!) Discuss/contrast data management in Object- Relational DBMS (PostgreSQL) vs. data management in sensor networks (TinyDB). (max 1 page)

28 Filmdatabasen Very small subset of the Internet Movie Database (IMDb) - Same as the one that was used in INF3100 Brief overview of datamodel in Filmdatabasen : infofilmdb.pdf Command to create your own copy ( username is your username): > psql -h kurspg -U username username Password for user username: Welcome to psql (server 8.2.4), the PostgreSQL interactive terminal. Type: \copyright for distribution terms \h for help with SQL commands \? for help with psql commands \g or terminate with semicolon to execute query \q to quit username=> \i /ifi/midgard/h01/jarleso/www_docs/filmdatabasen/install.sql

29 Filmdatabasen (ORM)

30 Filmdatabasen (ORM-UML)

31 Examples jarleso=> SELECT COUNT(*) FROM film; count (1 row) jarleso=> \i q3.sql - insert file <The answer of query 3> jarleso=> \d film Table "public.film" Column Type Modifiers filmid numeric(10,0) not null maintitle character varying(255) not null productionyear integer Indexes: "pkfilm" PRIMARY KEY, btree (filmid) "filmmaintitle" btree (maintitle) Check constraints: "yearrange" CHECK (productionyear >= 1889 AND productionyear <= 2050) jarleso=>

32 Examples jarleso=> SELECT TRIM(p.firstname + ' ' + p.middlename + ' ' + p.surname) AS full_name jarleso=> FROM person AS p jarleso=> WHERE p.surname = 'Aiello'; full_name Danny Aiello Gian Francesco Aiello Lorenzo Aiello Pier Francesco Aiello Rick Aiello Shu Aiello (6 rows)

33 Problems & Documentation Problems logging on: PostgreSQL documentation:

34 Need help? Questions? TinyDB frustrations? Jarle (jarleso at ifi.uio.no) or visit my office (3232)