Update docs/DESIGN.md

docs/DESIGN.md

@@ -4,6 +4,8 @@ This document contains background information on various design decisions, which
 
 ## Automatic Resolution and Randomization of Connection Addresses
 
+By default pyexasol resolves host names to IP addresses, randomly shuffles the IP addresses and tries to connect until connection succeeds. This has the following reasons:
+
 * This will ensure that if at least one hostname is unavailable, an exception will be raised. Otherwise, an exception will occur only when "random" selects a broken hostname, leading to unpredictable errors in production.
 
 * When you have a very large cluster with a growing number of nodes, it makes sense to put all nodes under one hostname, like `myexasol.mlan`, instead of having separate hostnames like `myexasol1..64.mlan`, especially when the number constantly changes. In this case, redundancy will not work properly if the hostname is not resolved beforehand, as we do not know if it points to a single address or multiple addresses.