Proxy settings are being set globally in JVM #1094
Description
Hi, we're experiencing issues with Snowflake connector in relation to PROXY settings. We have multiple Snowflake connectors on our Connect cluster - some of them use proxy settings, while some of them do not have any proxy configured. Even though for some of them there is no proxy set, those connectors are involuntarily using it because different Snowflake connector sets them globally in the whole JVM (which causes also different types of connector to use these settings which is yet another problem). I believe there should be an option to have proxy configured per connection only so that one connector does not affect connections of others (as per #533 "In the future, we'll want another method of adding proxy configurations without resorting to System.setProperty() calls").
Another problem we have is during connector creation. Even though we set "jvm.nonProxy.hosts", this setting is not respected and connector still tries to use proxy (which causes failure). I've digged a bit into Snowflake connector code and it seems like Utils::enableJVMProxy is only called during connector startup in SnowflakeSinkConnector::start and not during validation process (SnowflakeSinkConnector::validate) where test connection happens. It prevents us from creating the connector even though it would start fine, assuming NON PROXY hosts setting is in place. Would be good idea to setup validation connection with proxy settings too.