protected static ClickHouseDnsResolver newInstance() {
        ClickHouseDnsResolver resolver = null;

        if ((boolean) ClickHouseDefaults.SRV_RESOLVE.getEffectiveDefaultValue()) {
            try {
                resolver = new SrvResolver();
            } catch (Throwable e) {
                log.warn("Failed to enable SRV resolver due to:", e);
            }
        }

        return resolver == null ? new ClickHouseDnsResolver() : resolver;
    }
Default DNS resolver. It tries to look up service record (SRV record) when
{@link com.clickhouse.client.config.ClickHouseDefaults#SRV_RESOLVE} is set to
{@code true}.
clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseDnsResolver.java