private void addUnrecoveredRegion(long drId) {
    DiskRegionInfo dri = getOrCreateDRI(drId);
    if (dri.testAndSetUnrecovered()) {
      unrecoveredRegionCount.incrementAndGet();
    }
  }
Keeps track of the drId of Regions that have records in this oplog that have not yet been
recovered. If this count is > 0 then this oplog can not be compacted.
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java