Alright! We’ve just done another full round of QA tests against Build 593 to confidently declare it stable. We’ve been using it live on our own helpdesk for about a week.

There are a couple dozens tweaks and improvements included, but our major focus was on bringing knowledgebase management back to the worker GUI, integrating the public knowledgebase with the Support Center (to remove the need for two public tools) and performance improvements.

We’ve also switched over to requiring MySQL 4.1 to vastly simplify fulltext indexes for quicker searches, to get subquery and transaction support, and to move forward with internationalization. It was really useful to gather community feedback about this change ahead of time in the voting booth on the forums.

When we had to shuffle some of our hosted sites around during the server emergency last week, we ended up temporarily putting more sites on a single server than we normally would have liked. It was interesting to observe that about 100 concurrent copies of Cerberus Helpdesk 4.0 ran very usably on a mid-range Debian box (Dual Xeon 3GHz, 2GB RAM, 2×500GB RAID-1). In practice, for that kind of load, we’d throw more memory at the machine and probably bump up the RAID concurrency. The hard disks are almost always the bottleneck if you can’t keep databases entirely in memory.

Naturally we’re not in the habit of overselling a machine’s resources, but it gave us the opportunity to look at bottlenecks with that many copies of Cerb4 running. We used this information to add some last minute performance improvements to Build 593. One of the most effective was improved database indexing on the message_header table – which is used to thread incoming messages with the messages they’re replying to, as well as to display the original headers while reading ticket messages. There were a couple other missing indexes, and a few places in the code we could reduce unnecessary queries.

For the knowledgebase, you’re now able to use nested categories again (as was heavily requested). The top-level categories of the knowledgebase are now called “topics”, and you use topics to decide what branches of the knowledgebase to display on your various public community tool instances. You can display more than one topic for a particular website. We’ve found it’s most effective to use your products and services as the basis of topics.

To take advantage of the new community tool changes you’ll need to go into ‘Helpdesk Setup->Community Tools’ and choose your knowledgebase topics to display for each tool.

You can find the full changelog for Build 593 in the forums.