Also Reaper will skip the anticompaction phase which you might be going through with nodetool (depending on your version of Cassandra).
That'll reduce the overall time spent on repair and will remove some compaction pressure.

But as Erick said, unless you have past repairs to rely on and a stable data size, it is impossible to predict the time it takes for repair to complete.

Cheers,

Alex

Le lun. 23 mars 2020 à 12:44, Oleksandr Shulgin <oleksandr.shulgin@zalando.de> a écrit :
On Mon, Mar 23, 2020 at 5:49 AM Shishir Kumar <shishirroy2000@gmail.com> wrote:
Hi,

Is it possible to get/predict how much time it will take for nodetool -pr to complete on a node? Currently in one of my env (~800GB data per node in 6 node cluster), it is running since last 3 days.

Cassandra Reaper used to provide a reasonably accurate estimate as I recall.  Of course, the repair has to be triggered by Reaper itself--it's no use if you have already started it with nodetool.

Regards,
--
Alex