We decided to give HSQLDB a try.

The initial setup went smoothly. But when clicking on the "Test Forum" link in the "Category Test", the following error message appeared.

An error has occurred.



For detailed error information, please see the HTML source code, and contact the forum Administrator.



org.hsqldb.HsqlException: data exception: invalid row count in fetch first clause

Any thoughts on how to investigate further?
I did a search in templates/default for "fetch" and only found a reference to mail in admin_welcome.htm.
The button itself makes use of a FreeMarker tag "href:{$ForumLink}"
I haven't tried to track down the related Java code.

There are no errors or messages in the command shell. The last message was "Started @11583ms"

This error occurred both on the server and when I reinstalled on my laptop for a local test.

The configuration file I used for my local:

Step 2 - Verify Configuration
1) General Configuration
Default board language: en_US
Database Type: hsqldb
2) Database Configuration
Database Server Hostname: localhost
Database name: jforum
Database Username: root

Database Encoding: utf-8
Use Connection Pool: yes
3) Board Configuration
Forum Link: http://localhost:8080/jforum-2.6.1/
Website Link: http://localhost:8080
Administrator Username: Admin

I'll try to reproduce that. But looking at the volume of data on java-gaming.org, I think using HSQLDB (an embedded DB with a simplistic file storage approach) would not be a good choice.

Update: It happens for me as well. By the way, the full stack trace of the exception is in the HTML source code of that page, as the message suggests. Not that that will help someone unfamiliar with the code base, but it helps me

I will pass the recommendation on in regards to database choice!

I've just released version 2.6.2 which restores compatibility with HSQLDB.

I think either PostgreSQL and MySQL would be good choices as the DB - they're free, and the best tested (as you have just found out).

My partner located this Hsqldb bug report. Perhaps it is helpful?
https://sourceforge.net/p/hsqldb/bugs/1100/

His logic is this:

if JForum2 uses FETCH FIRST 0 ROWS, that's JForum2's bug
otherwise if JForum2 is specifying LIMIT 0, that's valid SQL, and it's HSQLDB's bug

Well, as I said, the new version fixes this - there was indeed a bug in JForum.

Thanks! I hadn't refreshed my browser and missed your first reply.

I tested JForum-2.6.2 and Hsqldb works great!

As an update: we are now having troubles now with getting Jetty to run as a service. Java is unable to write to the "/logs" directory, is the main error message. When manually starting, the logging works perfectly well. I'm guessing there's some file with the wrong address, as the permissions on the /logs directory do allow our limited "jetty" user to write.