fix(compaction): Remove compaction backoff mechanism (#1686)
fix(compaction): Remove compaction backoff mechanism (#1686)

We used to back-off from doing compaction if the allocated memory by
jemalloc is more than 16GiB. In case of heavy write load it is possible
that the compaction will continuously get backed-off and the SST tree
will get completely filled. This will cause the memtable flush to be stuck
which results in issues like Live-Loading getting stuck in dgraph.
dgraph-io/badger,dgraph-io/badger