public void setRTIngest(boolean rtIngest) {
        this.rtIngest = rtIngest;
        if (rtIngest && !localRealtimeTable.isIngestState()) {
            localRealtimeTable.start();
        }
        if (!rtIngest && localRealtimeTable.isIngestState()) {
            localRealtimeTable.stop();
        }
    }
This segment pool cache all realtime segment fds.
indexr-server/src/main/java/io/indexr/server/rt/RealtimeSegmentPool.java