https://github.com/aliartiza75/livecassandrareader

A script to read data from the Cassandra table in real time.
https://github.com/aliartiza75/livecassandrareader

cassandra cassandra-database cassandra-reader cassandra-table python3

Last synced: 16 days ago
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A script to read data from the Cassandra table in real time.

• Host: GitHub
• URL: https://github.com/aliartiza75/livecassandrareader
• Owner: aliartiza75
• Created: 2018-04-24T18:09:33.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-04-24T19:48:29.000Z (almost 7 years ago)
• Last Synced: 2024-11-18T08:29:08.409Z (3 months ago)
• Topics: cassandra, cassandra-database, cassandra-reader, cassandra-table, python3
• Language: Python
• Homepage:
• Size: 3.91 KB
• Stars: 0
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# livecassandrareader

A script to read data from the Cassandra table in real time.

# Problem

The current version of the python-driver reads the data from the Cassandra table till a particular row but what if the table is updating in real-time, so in order to read the new data from a table we have to go through all the rows again.

For example:

A **USER** table have 100 rows in it. So using the script below:

```python

self.session.default_fetch_size = 10

result_set = self.session.execute("SELECT * FROM testKeyspace.USER")

    while(result_set.has_more_pages):

        for row in result_set.current_rows:

            print(row)

        page_state = result_set.paging_state

        result_set = self.session.execute("SELECT * FROM test3rf.test", paging_state=page_state)

```

we will be able to read the cassandra table till 100th. After some time the **USER** table gets updated with two new rows. So in order to read the two new rows we have to go through all the other 100 rows which is inefficient. 

# How to use it

It supports both python2 & 3 version.

Install the python cassandra driver using the command given below:

```

$ pip install cassandra-driver

```

LiveCassandraReader class need the following argument as an input:

```

configurations = {

    "cass_addr": "172.17.0.1",

    "keyspace_name": "dataingestion",

    "query": "SELECT * FROM dataingestion.power_source_status4",

    "protocol_version": 4,

    "retry": 5,

    "retry_time": 10,

    "default_fetch_size": 1

}

```

To run the script"

```

$ python livecassandrareader.py

```