Daily Archives: January 28, 2016


Cassandra production scenarios/issues

Production issue: when we are trying to write a select query with 8 lacks ids “in condition “. then we got faced below issue,    To solve the above exception, we used distributed calls in Java client as shown below,

Few Production configurations in cassandra RetryPolicy Three scenarios you can control retry policy for: Read time out: When a coordinator received the request and sent the read to replica(s) but the replica(s) […]


Cassandra query language (CQL) and Cassandra Java Client Example

Cassandra Table structure/Terminology Before going to learn CQL commands, we just need to know terminology in cassandra. RDBMS Cassandra Terminology Database Keyspace Table Column Family Primary key Row Key Column name Column name Column value column value CQL Commands Creating a key-space

Use the keyspace (will use that key space)

Note: key spaces are equivalent to database/schema in RDBMS Get list of key spaces

Create table

Get list […]


Cassandra write and read process

Storage engine Cassandra uses a storage structure similar to a Log-Structured Merge Tree, unlike a typical relational database that uses a B-Tree. Cassandra avoids reading before writing. Read-before-write, especially in a large distributed system, can produce stall in read performance and other problems. Cassandra never re-writes or re-reads existing data, and never overwrites the rows in place. How data is written? Different stages of write process in cassandra Logging data […]


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I have attended Siva’s Spark and Scala training. He is good in presentation skills and explaining technical concepts easily to everyone in the group. He is having excellent real time experience and provided enough use cases to understand each concepts. Duration of the course and time management is awesome. Happy that I found a right person on time to learn Spark. Thanks Siva!!!

Dharmeswaran ETL / Hadoop Developer Spark Nov 2016 September 21, 2017

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