difin commented on code in PR #5753: URL: https://github.com/apache/hive/pull/5753#discussion_r2055097284
########## testutils/hadoop: ########## @@ -69,6 +69,7 @@ fi HADOOP_OPTS="$HADOOP_OPTS -Dhadoop.policy.file=$HADOOP_POLICYFILE" # Disable ipv6 as it can cause issues +# TODO: change to -Djava.net.preferIPv4Stack=false after Hadoop adds support for IPv6 HADOOP_OPTS="$HADOOP_OPTS -Djava.net.preferIPv4Stack=true" Review Comment: Hadoop currently doesn't support IPv6, and I haven't found info about any hadoop libraries to support IPv6. However, the default behavior on dual stack IPv4/IPv6 hosts is to prefer IPv4 addresses when available. Currently, Hive can't work on IPv6-only hosts, but on dual-stack hosts it should work properly and prefer to bind to IPv4 addresses. This is from Java Networking doc: > **IPv4 / IPv6** > **java.net.preferIPv4Stack (default: false)** > If IPv6 is available on the operating system the underlying native socket will be, by default, an IPv6 socket which lets applications connect to, and accept connections from, both IPv4 and IPv6 hosts. However, in the case an application would rather use IPv4 only sockets, then this property can be set to true. The implication is that it will not be possible for the application to communicate with IPv6 only hosts. > > **java.net.preferIPv6Addresses (default: false)** > When dealing with a host which has both IPv4 and IPv6 addresses, and if IPv6 is available on the operating system, the default behavior is to prefer using IPv4 addresses over IPv6 ones. This is to ensure backward compatibility, for example applications that depend on the representation of an IPv4 address (e.g. 192.168.1.1). This property can be set to true to change that preference and use IPv6 addresses over IPv4 ones where possible. When `java.net.preferIPv4Stack=false` and `java.net.preferIPv6Addresses=false`, both IPv4 and IPv6 are available, but Java prefers to use IPv4 addresses unless it can find only IPv6 (for example, if your /etc/hosts maps localhost only to ::1, it will use IPv6, but on properly configured system it won't happen) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: gitbox-unsubscr...@hive.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: gitbox-unsubscr...@hive.apache.org For additional commands, e-mail: gitbox-h...@hive.apache.org
