https://s3.amazonaws.com/clickhouse-test-reports/0/10dc83b7a9c18228c4a4fc0dcfe6b18d2427462e/stress_test__debug__actions_.html

I found weird exception while investigating why ephemeral nodes were not removed for a long time:
https://pastila.nl/?00ec9776/d8858e442f8453f9b9e31a2f1da3cc8b
{
    return checkInit() && hasLeader() && !server->isRecovering();
}
void KeeperDispatcher::updateConfiguration(const Poco::Util::AbstractConfiguration & config)
{
    auto diff = server->getConfigurationDiff(config);
    if (diff.empty())
        LOG_TRACE(log, "Configuration update triggered, but nothing changed for RAFT");
    else if (diff.size() > 1)
        LOG_WARNING(log, "Configuration changed for more than one server ({}) from cluster, it's strictly not recommended", diff.size());
    else
        LOG_DEBUG(log, "Configuration change size ({})", diff.size());
    for (auto & change : diff)
    {
        bool push_result = update_configuration_queue.push(change);
        if (!push_result)
            throw Exception(ErrorCodes::SYSTEM_ERROR, "Cannot push configuration update to queue");
    }
}
void KeeperDispatcher::updateKeeperStatLatency(uint64_t process_time_ms)