Shawn, On 4/10/18 10:16 AM, Shawn Heisey wrote: > On 4/10/2018 7:32 AM, Christopher Schultz wrote: >>> What happened is that the new core directory was created as root, >>> owned by root. >> Was it? If my server is running as solr, how can it create directories >> as root? > > Unless you run Solr in cloud mode (which means using zookeeper), the > server cannot create the core directories itself. When running in > standalone mode, the core directory is created by the bin/solr program > doing the "create" -- which was running as root.
That is ... surprising.[1] > I know that because > you needed the "-force" option. So the core directory and its "conf" > subdirectory (with the config) are created by the script, then Solr is > asked (using the CoreAdmin API via http) to add that core. It can't, > because the new directory was created by root, and Solr can't write the > core.properties file that defines the core for Solr. Okay, then that makes sense. I'll try running bin/solr as "solr" via sudo instead of merely as root. I was under the mistaken impression that the server kept its own files in order. It also means that one cannot remote-admin a Solr server. :( > When running Solr in cloud mode, the configs are in zookeeper, so the > create command on the script doesn't have to make the core directory in > order for Solr to find the configuration. It can simply upload the > config to zookeeper and then tell Solr to create the collection, and > Solr will do so, locating the configuration in ZooKeeper. Good to know, though I'm not at the stage where I'm using ZK. > You might be wondering why Solr can't create the core directories itself > using the CoreAdmin API except in cloud mode. This is because the > CoreAdmin API is *OLD* and its functionality has not really changed > since it was created. Historically, it was only designed to add a core > that had already been created. *snapping sounds from inside brain* > We probably need to "fix" this ... but > it has never been a priority. There are bigger problems and features to > work on. Cloud mode is much newer, and although the Collections API > does utilize the CoreAdmin API behind the scenes, the user typically > doesn't use CoreAdmin directly in cloud mode. > >> The client may be running as root, but the server is running as 'solr'. >> And the error occurs on the server, not the client. So, what's really >> going on, here? > > I hope I've explained that clearly above. You have. Running bin/solr as user 'solr' was able to create the core. The way the installer and server work together is very unfortunate. bin/solr knows the euid of the server and, if running under root/sudo could easily mkdir/chown without crapping itself. Having installed a "service" using the Solr installer practically requires you to run bin/solr using sudo, and then it doesn't work. Is there a JIRA ticket already in existence where I can leave a comment? Thanks, -chris [1] https://en.wikipedia.org/wiki/Principle_of_least_astonishment
