let kvs = parse(RDB)
for (key, val) in kvs
 if val is map 
 for (field, value) in val
 // execute migration
 redis.HSET(key, field, vlaue)
 if val is string
 // execute migration
 redis.SET(key, val)
 ...
 ...

let kvs = parse(RDB)
for (key, val) in kvs
 let dump-val = convertToDump(val)
 let lower-dump-val = convertToLowerDump(dump-val)
 // execute migration
 redis.RESTORE(key, lower-dump-val)

// Downgrade migration from redis-7.0.0 to redis-6.0.0
Replicator replicator = new RedisReplicator("redis://127.0.0.1:6379");
replicator.setRdbVisitor(new DumpRdbVisitor(replicator, 9));
replicator.addEventListener(new EventListener() {
 @Override
 public void onEvent(Replicator replicator, Event event) {
 if (event instanceof DumpKeyValuePair) {
 DumpKeyValuePair dkv = (DumpKeyValuePair) event;
 byte[] serialized = dkv.getValue();
 // Use redis RESTORE command to migrate serialized data to target redis.
 }
 }
});
replicator.open();

// Create a DumpRdbVisitor Rdb parser to parse rdbv10 format into rdbv9 format
replicator.setRdbVisitor(new DumpRdbVisitor(replicator, 9));

// Register event listener, where serialized is the byte array downgraded to rdbv9
// It can be directly migrated to target database using the RESTORE command
replicator.addEventListener(new EventListener() {
 @Override
 public void onEvent(Replicator replicator, Event event) {
 if (event instanceof DumpKeyValuePair) {
 DumpKeyValuePair dkv = (DumpKeyValuePair) event;
 byte[] serialized = dkv.getValue();
 }
 }
});

# Redis-rdb-CLI internally relies on Redis-replicator
# The first step of migration requires changing the configuration file /path/to/redis-rdb-cli/conf/redis-rdb-cli.conf
# Change dump_rdb_version from -1 to 9
$ sed -i 's/dump_rdb_version=-1/dump_rdb_version=9/g' /redis-rdb-cli/conf/redis-rdb-cli.conf
# Execute migration command, data will be automatically downgraded to lower version DUMP format
$ rmt -s redis://com.redis7:6379 -m redis://com.redis6:6379 -r