Cloud Computing Workshop 2013, ITU

1. 4: Interfacing with Cassandra
Zubair Nabi
zubair.nabi@itu.edu.pk
April 20, 2013
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2. Introduction1
Project website: http://cassandra.apache.org/
1
Disclaimer: Based on the wonderful talk given by Jeremiah Jordan at PyCon 2012
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3. Introduction1
Project website: http://cassandra.apache.org/
Column based key value store (multi-level dictionary)
1
Disclaimer: Based on the wonderful talk given by Jeremiah Jordan at PyCon 2012
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4. Introduction1
Project website: http://cassandra.apache.org/
Column based key value store (multi-level dictionary)
Consists of keyspaces and column families
1
Disclaimer: Based on the wonderful talk given by Jeremiah Jordan at PyCon 2012
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5. Introduction1
Project website: http://cassandra.apache.org/
Column based key value store (multi-level dictionary)
Consists of keyspaces and column families
Keyspace: Namespace for column families (typically one per
application)
1
Disclaimer: Based on the wonderful talk given by Jeremiah Jordan at PyCon 2012
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6. Introduction1
Project website: http://cassandra.apache.org/
Column based key value store (multi-level dictionary)
Consists of keyspaces and column families
Keyspace: Namespace for column families (typically one per
application)
Column family: Contains multiple columns, each of which has a name,
value, and timestamp, and which are referenced by row keys
1
Disclaimer: Based on the wonderful talk given by Jeremiah Jordan at PyCon 2012
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9. Starting up
Running it: sudo cassandra -f
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10. Starting up
Running it: sudo cassandra -f
Running the CLI: cassandra-cli
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11. Creating a keyspace
Connecting to the store: connect localhost/9160;
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12. Creating a keyspace
Connecting to the store: connect localhost/9160;
Creating a keyspace: create keyspace ApplicationData
with placement_strategy =
’org.apache.cassandra.locator.SimpleStrategy’
and strategy_options =
[{replication_factor:1}];
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13. Creating a column family
Referencing a keyspace: use ApplicationData;
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14. Creating a column family
Referencing a keyspace: use ApplicationData;
Creating a column family: create column family UserInfo
and comparator = ’AsciiType’;
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15. Interfacing with Cassandra in Python
Package: pycassa
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16. Interfacing with Cassandra in Python
Package: pycassa
Webpage: https://github.com/pycassa/pycassa
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17. Pycassa Basics
1 import pycassa
2 from pycassa.pool import ConnectionPool
3 from pycassa.columnfamily import ColumnFamily
4
5 pool = ConnectionPool(’ApplicationData’,
6 [’localhost:9160’])
7 col_fam = ColumnFamily(pool, ’UserInfo’)
8 col_fam.insert(’John’, {’email’: ’john@gmail.com’})
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18. Read
1 readData = col_fam.get(’John’,
2 columns=[’email’])
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19. Delete
1 col_fam.remove(’John’,
2 columns=[’email’])
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20. Batch
1 col_fam.batch_insert(
2 {’John’: {’email’: ’john@gmail.com’,
3 ’state’: ’IL’,
4 ’gender’: ’M’},
5 ’Jane’: {’email’: ’jane@python.org’,
6 ’state’: ’CA’
7 ’gender’: ’M’}})
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21. Batch Stream
1 b = col_fam.batch(queue_size=10)
2
3 b.insert(’John’,
4 {’email’: ’john@gmail.com’,
5 ’state’: ’IL’,
6 ’gender’: ’M’})
7
8 b.insert(’Jane’,
9 {’email’: ’jane@python.org’,
10 ’state’: ’CA’})
11
12 b.remove(’John’, [’gender’])
13 b.remove(’Jane’)
14 b.send()
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22. Batch Read
1 readData = col_fam.multiget([’John’, ’Jane’, ’Bill’])
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23. Column Slice
1 d = col_fam.get(’Jane’,
2 column_start=’email’,
3 column_finish=’state’)
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24. Reference(s)
Apache Cassandra and Python:
https://pycon-2012-notes.readthedocs.org/en/
latest/apache_cassandra_and_python.html
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