Deb,
I've been using Moodle for a long time, but have never really used chat for anything other than occasional "virtual" office hours. However, for the past year I've been working with a task force on our campus to "evaluate" Moodle as a possible replacement for BB. After some planning and training in the fall, we have implemented a small pilot this spring. We have an online program that uses chat a lot in the delivery of their classes and a "reliable/functional" chat utility is a must for that program.
A couple of weeks ago, we had 70 students attempt to join chat sessions (in about 7 chat rooms) in one class...after about 40 students logged on then system crashed. We have a great server/systems admin on campus and I sat down with him for about 2-hours yesterday and did a lot of server and Moodle tuning. Last night we had a second chat session with 70 students and everything went well. The professor had a "main chat room" where all the students logged into initially, then she sent them to break-out chat rooms for small group chats while groups rotated through the main chat room with her. We had around 70 students logged in chatting for over an hour and a half with no (chat) problems last night...we are still dealing with several other problems.
I think you will find that the chat feature is the single biggest resource hog in Moodle and addressing this issue will always require server and Moodle tuning--it's not strictly a server issue or a Moodle issue--it seems to be both. So, if your admin doesn't think it's a server issue, then you're probably not going to be able adequately address this problem.
Here is the email my server admin sent this morning after monitoring the server during the chat last night. We're running Moodle on a single, dedicated server with only 2gb of RAM, we're not running a chat daemon, and we're not using the stream method. We changed the chat_refresh_userlist to 60, chat_old_ping to 60, and chat_refresh_room to 15. Actually, while the chat was up on the first test, students complained that the window was scrolling too fast, so changing the chat_refresh_room from 5 to 15 helped them (they liked it better last night) and helped us significantly reduce the server load. We made several other server tweaks that my sys admin knows a lot more about that I.
Also, (in my opinion) you are using the absolute worst version of Moodle you could possible be using--1.7. It was a disaster when it was released and I don't think it has gotten much better since....in my opinion you would be far better off using any version before or after that version. As I indicated above, Moodle (or the Moodle version) alone isn't the complete answer to chat problems, but it sure won't hurt...being on 1.6, 1.8 or even 1.9 beta would be better than 1.7--in my opinion. We're testing 1.8 on our campus. I use 1.6 for all my "other" stuff.
Just some food for thought...
Steve
