Alter autogen retention policy and drop data older than 1 year on an existing database

I have altered the default retention policy to keep data for 1 year only. (it used to be infinite)
show retention policies
name duration shardGroupDuration replicaN default

autogen 8736h0m0s 168h0m0s 1 true

I assume it automatically apply to my existing database (since autogen is the only retention policy I have)
after I altered the retention policy I restarted influxdb but it still contains the old data, shouldn’t the old data be dropped immediately per new retention policy? or did I do something wrong?

Usually once the data is expired they will dropped even without restart. Infact the entire shard group will be dropped after it is expired and not like one data at a time. May be I guess it took time for dropping the entire shards. Does the issue still exist now?

that was completely correct… when the data expired the shard was dropped… thanks very much @Avin