Does the objects of kafka topics deleted from the broker remain while the consumer is running?

[atkei]

I checked with v1.9.2.

I have the following 2 applications and app2's memory usage increases.

• app1 dynamically creates/deletes topics.
• app2 subscribes to topics created by app1 and unsbscribes topics deleted by app1.

My consumer's metrics output as follows. Topic 0 is already deleted from broker and unsubscribed from consumer, but deleted topic + UA partiton info still exists.

...
      "topics": {
        "0": {
          "topic": "0",
          "age": 306043,
          "metadata_age": 889,
          "batchsize": {
            "min": 0,
            "max": 0,
            "avg": 0,
            "sum": 0,
            "stddev": 0,
            "p50": 0,
            "p75": 0,
            "p90": 0,
            "p95": 0,
            "p99": 0,
            "p99_99": 0,
            "outofrange": 0,
            "hdrsize": 14448,
            "cnt": 0
          },
          "batchcnt": {
            "min": 0,
            "max": 0,
            "avg": 0,
            "sum": 0,
            "stddev": 0,
            "p50": 0,
            "p75": 0,
            "p90": 0,
            "p95": 0,
            "p99": 0,
            "p99_99": 0,
            "outofrange": 0,
            "hdrsize": 8304,
            "cnt": 0
          },
          "partitions": {
            "-1": {
              "partition": -1,
              "broker": -1,
              "leader": -1,
              "desired": false,
              "unknown": false,
              "msgq_cnt": 0,
              "msgq_bytes": 0,
              "xmit_msgq_cnt": 0,
              "xmit_msgq_bytes": 0,
              "fetchq_cnt": 0,
              "fetchq_size": 0,
              "fetch_state": "none",
              "query_offset": -1001,
              "next_offset": 0,
              "app_offset": -1001,
              "stored_offset": -1001,
              "commited_offset": -1001,
              "committed_offset": -1001,
              "eof_offset": -1001,
              "lo_offset": -1001,
              "hi_offset": -1001,
              "ls_offset": -1001,
              "consumer_lag": -1,
              "consumer_lag_stored": -1,
              "txmsgs": 0,
              "txbytes": 0,
              "rxmsgs": 0,
              "rxbytes": 0,
              "msgs": 0,
              "rx_ver_drops": 0,
              "msgs_inflight": 0,
              "next_ack_seq": 0,
              "next_err_seq": 0,
              "acked_msgid": 0
            }
          }
        },
    ...

In my understanding, deleted topic and partition objects (rd_kafka_toppar_t) remain while consumer main thread is running.
https://github.com/edenhill/librdkafka/blob/v1.9.2/src/rdkafka.c#L2118

If it's correct, Should I re-create consumer object periodically to reduce memory usage increase? Is there other way?

Thanks.

[atkei]

Close because it's known issue.
#4214