I'm using the sstableloader's command to load the backup and I note that the new datas not load. Analising the files, the new datas still in the commit log and not in the backup. How could I force the "commit" the commit log datas in the memtables?
So normally, I'd say try running a nodetool flush. If data is getting flushed from memory to disk, it should remove the corresponding commitlog file.
If that's not happening, the next thing I would try is stopping the node with nodetool drain and then stopping the Cassandra process. When you restart it, the node will process the commitlogs and reconcile them with data stored on disk.