Book Image

Apache Cassandra Essentials

By : Nitin Padalia
Book Image

Apache Cassandra Essentials

By: Nitin Padalia

Overview of this book

Apache Cassandra Essentials takes you step-by-step from from the basics of installation to advanced installation options and database design techniques. It gives you all the information you need to effectively design a well distributed and high performance database. You’ll get to know about the steps that are performed by a Cassandra node when you execute a read/write query, which is essential to properly maintain of a Cassandra cluster and to debug any issues. Next, you’ll discover how to integrate a Cassandra driver in your applications and perform read/write operations. Finally, you’ll learn about the various tools provided by Cassandra for serviceability aspects such as logging, metrics, backup, and recovery.
Table of Contents (14 chapters)
Apache Cassandra Essentials
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Restoring data to Cassandra


In order to restore data from a snapshot onto a node, follow these steps:

  1. Shut down the node.

  2. Delete the old commitlog files:

    // package based installation
    $ rm /var/lib/cassandra/commitlog/*
    // Tar based installation
    $ rm <install-directory/data/commitlog/*
    
  3. Delete the old SSTable files from <data-dir>/<keyspace-name>/<column-family-name>/:

    // package based installation
    $ rm /var/lib/Cassandra/data/apache_cassandra_demo_db/user_table-f99a8ec0110611e5833fa9b7a6da1962/*.db
    // Tar based installation, considering tar is unpacked at /opt/cassandra location
    $ rm /opt/cassandra/data/data/apache_cassandra_demo_db/user_table-f99a8ec0110611e5833fa9b7a6da1962/*.db
    
  4. Copy the latest snapshots from the snapshot location to the data directory:

    // package based installation
    $ cp –p /var/lib/Cassandra/data/apache_cassandra_demo_db/user_table-f99a8ec0110611e5833fa9b7a6da1962/snapshots/1437860306074/* /var/lib/Cassandra/data/apache_cassandra_demo_db/user_table...