ctubbsii commented on PR #2037: URL: https://github.com/apache/zookeeper/pull/2037#issuecomment-1828187021
> This issue seems back to 2014 where the reason for doing so is "consistent with Hadoop's flavor". > > I tend to avoid adding this new logic as long as the original `ZOOKEEPER_HOME` detected logic is always true: Said from `$0` and depends on the folder structure, if it's always the correct ZOOKEEPER_HOME, why do we introduce a new envvar that is possibly misspelled? The idea of a `_HOME` environment is a pretty unreliable convention, and tends to cause headaches for downstream packagers/redistributors trying to integrate an application into the conventions of the target system. Most Linux distros have conventions for where to place specific files... like /usr/bin/ for binaries, where /usr can typically be mounted read-only, and /etc for config, which typically needs to be mounted with write capability. If an application is deployed in such a typical Linux environment, it'd be very unusual for a user to be able to completely change how the installed software interacts with its own installed binaries by setting some user environment variable. Imagine these scripts installed in `/usr/bin/`, but then the user sets `ZOOKEEPER_HOME`. Now, you can have a strange situation where the user calls `/usr/bin/zkCli.sh`, but that calls `/home/somebody/Desktop/zookeeper/bin/zkEnv.sh` because the `ZOOKEEPER_HOME` is set, which then sets up a `CLASSPATH` point ing back to `/usr/share/zookeeper/zookeeper-*.jar` instead of `/home/somebody/Desktop/zookeeper/lib/zookeeper-*.jar`. Now, you have a mix of binaries and libraries being used from one installation in the system and another installation defined by user config. It's too confusing, and it's an awful convention. I don't think Hadoop's convention is worth following... it's just not very friendly to downstream packagers/redistributors/users. I think it's same to assume that however you got to a particular installation's binaries, the other binaries from the same installation are in the same directory. So, you don't need to redirect towards `ZOOKEEPER_HOME` in these... you can just use `$0` to find the current script and its sibling scripts from the same installation. Now, if you want to use `ZOOKEEPER_HOME` to find the initial installation, that's reasonable. But it's not reasonable to use it internally within an installation. -- 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: notifications-unsubscr...@zookeeper.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
