What is gc grace in Cassandra

Question

I was watching DS201 course on Datastax and the lecturer started using the term "GC GRACE" out of nowhere.

What exactly are "GC Grace" and "gc_grace_seconds" ?

Answer 1

'gc_grace_seconds' is the time (in seconds, defined in Table properties) cassandra keep Tombstone so that other nodes which might be down during deletion of data can know the changes.

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