Cassandra does not load commitlog from the data folder

I am new to cassandra, but i want to resotore cassandra back up.

While restoring cassandra does not load data which is not yet commited to mem table and available in the Commitlog. as i know it has benchmark based on that it will commit the data in data base but while restoration it shoul load all the logs and data.

please help

i copy all the cassandra data files in to my new cassandra installation folder. and try to restore restore the backup.

befor that i have create new cassandra server, created Keyspace and tables on new server.

then i copyied all data files in the respected tables folder.

then restarted the cassandra. and run cassandra nodetool refresh commmand.

You cannot just copy the commit logs from one node to another, even if it is on the same server with a fresh installation because it is technically a different node (a new host ID is allocated on new installations).

In Cassandra, you cannot simply copy files from one node to another to restore the data. You need to take a snapshot of the data which is the equivalent of a cold backup in traditional RDBMS but doesn't require downtime.

If you're interested, I've explained the procedure in https://dba.stackexchange.com/questions/316520/.

Since you're new to Cassandra, I would recommend watching this short video on the basics of Cassandra backups and how snapshots work. If you want to learn more about Cassandra, we have several courses at DataStax Academy and they're all FREE. Cheers!