Elassendra backup Solution

Question

We have three node cluster for Cassandra/Elassandra and I needs to setup backup for this. I used "nodetool snapshot" command for taking backup, but as we are using elasticserach so do I need to take separate backups of Indices or taking backup from "nodetool snapshot" is enough for this.

if separate backup is required for indices then can you pls suggest me how to take backup/restore because there is no proper documentation for taking elassendra backup/restore

Thanks

Answer 1

Since Elassandra = Elasticsearch + Cassandra, So you need backup from Cassandra on the same time of backup from Elasticsearch.

By design, Elassandra synchronously updates Elasticsearch indices on the Cassandra write path. Therefore, Elassandra can backup data by taking a snapshot of Cassandra SSTables and Elasticsearch Lucene files on the same time on each node, as follows :

For Cassandra SSTables use:

nodetool snapshot --tag <snapshot_name> <keyspace_name>

And for index files use copy them by:

cp -al $CASSANDRA_DATA/elasticsearch.data/<cluster_name>/nodes/0/indices/<index_name>/0/index/(_*|segment*)      $CASSANDRA_DATA/elasticsearch.data/snapshots/<index_name>/<snapshot_name>/

However there is a documentation on Elassandra to Backup and Restore.