Auto reconnect to Binance Websocket after 24 hours

Question

I'm currently experimenting on Binance Websocket ( https://binance-docs.github.io/apidocs/spot/en/#websocket-market-streams ), streaming the candlestick data for processing.

As documented, the stream will randomly close after 24 hours. What's the best way to continue the session without interruption? I mean disconnect/reconnect after 23 hours so the program will continue without losing its state.

Here's what I did. I'm using the binance-java-api https://github.com/binance-exchange/binance-java-api .

And here's how I connect:

BinanceApiWebSocketClient client =
    BinanceApiClientFactory.newInstance(
            appConfig.getApiKey(),
            appConfig.getApiSecret(),
            appConfig.isUseTestNet(),
            appConfig.isUseTestNet())
        .newWebSocketClient();


client.onCandlestickEvent(cryptoPair.toLowerCase(), getCandlestickInterval(),
    new BinanceApiCallback<>() {
      @Override
      public void onResponse(final CandlestickEvent evt) {}

Answer 1

To solve this issue, I have used a scheduler/timer to reconnect the session every 12 hours. Since I'm using the Quarkus framework, it's readily available.

Solution: SessionManager class:

@Singleton
@Slf4j
@RequiredArgsConstructor
public class SessionManagerScheduler {

  final BinanceEventHandler binanceEventHandler;

  @Scheduled(cron = "0 2 */12 * * ?")
  public void reconnectSession() {

    log.info("Keep-Alive: Binance Session Via WebSocket -------------------------");

    binanceEventHandler.timeout();
  }
}

The Binance event handler:

@ApplicationScoped
@Slf4j
@RequiredArgsConstructor
public class BinanceEventHandler {

  final AppConfig appConfig;
  final CandlestickAccumulator candlestickAccumulator;
  final CandlestickMapper candlestickMapper;

  private Closeable candleStream = null;

  public void start() {

    streamCandleEvent();
  }

  public void timeout() {

    try {
      candleStream.close();

      streamCandleEvent();

    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  private void streamCandleEvent() {

    String cryptoPair = String.join(",", appConfig.getCryptoPairs());

    log.info("Start listening to cryptoPair={}", cryptoPair);

    candleStream = getClient().onCandlestickEvent(cryptoPair.toLowerCase(), getCandlestickInterval(),
        new BinanceApiCallback<>() {
          @Override
          public void onResponse(final CandlestickEvent evt) {

            if (!evt.getBarFinal()) {
              return;
            }

            log.debug("Processing cryptoPair={}, event={}", cryptoPair, evt);

            Candlestick candlestick = candlestickMapper.asCandleStick(evt);

            candlestickAccumulator.processCandlestickEvent(candlestick);
          }

          @Override
          public void onFailure(final Throwable cause) {

            Application.hasError = true;
            log.error("Fail connecting to Binance API {}", cause.getMessage());
          }
        }
    );
  }

  private BinanceApiWebSocketClient getClient() {

    return BinanceApiClientFactory.newInstance(
            appConfig.getApiKey(),
            appConfig.getApiSecret(),
            appConfig.isUseTestNet(),
            appConfig.isUseTestNet())
        .newWebSocketClient();
  }

  private CandlestickInterval getCandlestickInterval() {
    return CandlestickInterval.valueOf(appConfig.getCandlestickInterval());
  }
}