Ignore the advice below at your own peril.
There are a few main things that should be known before joining the discussion on IRC:
Sometimes the mailing list is a better option than one of the IRC channels. There's less chance of an instant response or interactive discussion, but the audience is much much larger -- over three thousand email addresses are subscribed to the solr-user mailing list. Many problems mentioned on the IRC channel are referred to the user list. If you don't get a response to your question within a reasonable timeframe (keeping timezones, the day of the week, and any holidays in mind), consider sending your question to the user list.
- Just ask your question as soon as you log in, providing as much detail as you can right up front. If you start with a greeting, asking if anyone is there, or asking whether it's OK to ask a question, chances are very good that you'll be completely ignored. You might interpret this as rudeness, but that is not the intent. Most of the residents of the channel are busy people, and may not even see what you've said at all because they aren't actually looking at the IRC program on their computer. It takes time to respond to greetings or requests that have nothing to do with the technical nature of the channel, so many of them simply won't respond.
When writing your question, please be aware of the XY problem trap. Try not to fall into it.
Once you do ask a technical question that's relevant to the channel, it may literally be hours before someone with the knowledge to respond will actually see your question. IRC has a reputation of being an instant method of communication, but that can only happen if all parties are actually present and paying attention right at that moment. IRC brings together people from all around the world, and the people who can answer your questions may be in a very different timezone. They might be asleep.
- Most of the people in the channel who can help are active during business hours in the USA. There are a few of them who reside in other timezones, primarily those in Europe. Keep that in mind when deciding how long you will wait for an answer.
- People who do not know the answer will usually ignore the question. They may even carry on other conversations as if you never asked your question. This will seem rude to an IRC newcomer, but consider this: Those people think it would be MORE rude if they were to respond to a discussion where they cannot offer anything useful.
- Once you have the attention of another channel user, resist any temptation to take the conversation private. In accordance with open source ideals, we prefer all communication to be in the open, for the benefit of all. If you need to share details about your setup that you don't want the public to see, sending that part of the communication privately is understandable and acceptable.
- There's some info further down on this page about how to share large data from configs and logs. That's extremely important.
Also see this blog post about etiquette for technical IRC channels. That page links to ESR's How to Ask Questions the Smart Way. The IRC etiquette page says that ESR's book insults the reader. That's an accurate assessment, but if you read the whole thing (it's very long) it's a perfect way to understand how open source communities function for users needing help. Most community members really do want to help everyone.
The blog post about IRC etiquette also mentions Gist for relaying large text content. That's an awesome choice. Another is the paste website maintained by the Apache foundation itself. One common website for this is pastebin.com, which is the original pastebin website and works very very well, but that website is extremely ad-heavy, so try to avoid it. Other good choices are pastie.org and Fedora pastebin. If you already have a favorite, please use it. If you need to relay binary content (pictures, etc), file sharing sites like Dropbox may be a better choice.
There may be information in your configs and logs that an attacker could use to compromise your security. Feel free to redact information like that, but do so in a consistent way that preserves the ability to tell one piece of redacted information apart from another, and don't remove any other kind of information. If you redact too much, you may need to divulge some of that information in order to get help, but those who offer legitimate help will never ask you for passwords. That kind of information is almost never required for troubleshooting.
There are two primary IRC channels dedicated to Solr at freenode.net. The channel names below are links to a web-based IRC client, preloaded with the channel indicated.
Did you read all of the advice above before scrolling down here to get to the IRC channels?
If you haven't read what's written above, please go back and read, so you have the information needed for success on IRC.
#solr -- Channel for Solr user questions. This includes development of user client code for interaction with Solr.
#solr-dev -- Hangout for discussion of Solr development. Mostly this means development of Solr itself, or for low-level plugin development. If you are developing client code, please use the #solr channel instead.
The IRC channels can be used for online discussion about Lucene/Solr. Committers on the Lucene/Solr project commonly hang out in one or both of these channels. Committers, contributors, and users should be careful to transfer all official decisions or useful discussions that happen on the IRC channels to the mailing list, this wiki, the official documentation, and/or the issue tracking system. The official documentation is created from data in the source code repository, and can only be changed by committers, but input from users (via mailing lists, Jira, IRC, etc) is taken seriously.