presto-main/src/main/java/io/prestosql/operator/ExchangeClient.java/ExchangeClient/clientFailed
class ExchangeClient:    private synchronized void clientFailed(Throwable cause)
    {
        // TODO: properly handle the failed vs closed state
        // it is important not to treat failures as a successful close
        if (!isClosed()) {
            failure.compareAndSet(null, cause);
            notifyBlockedCallers();
        }
    }