Extract schema from system_schema keyspace¶

Prerequisites

1. You have the snapshot tag.

2. The snapshot contains system_schema keyspace.

Procedure

1. List files of snapshot we want to restore (replace <node_id> with ID of one of the nodes in the cluster.

   sctool backup files --cluster my-cluster -T sm_20200513104924UTC -K system_schema --with-version | grep "<node_id>" > backup_files.out
   

2. Create a directory, and recreate table directories in it.

   mkdir scylla
   cd scylla
   cat ../backup_files.out | awk '{print $2}' | sort | uniq | xargs mkdir -p
   

3. Download the SSTables to the created directories

   cat ../backup_files.out | xargs -n2 aws s3 cp
   cd ..
   

4. Start the Scylla container with mounted data volume. Make sure to use the same Scylla version used to create the backup.

   docker run --name scylla -p 9042:9042 -v `pwd`/scylla:/var/lib/scylla/data --memory 1G --rm -d scylladb/scylla:4.3.0
   

5. Extract schema:

   cqlsh 127.0.0.1 -e "DESCRIBE SCHEMA"  > db_schema.cql