Thanks all for the quick answers. In terms of sizing, we could have several thousands (max = 10,000; more realistically 3,000) tickets submissions within a day. They will not be nicely spread during the day. Some hours might be a lot busier than others. Each ticket will have at least one attachment (about 1 to 3 mb each).
I am just starting to learn about MySQL Cluster, trying to find an architecture that could be robust enough to minimize data loss in case of failure. In other words, we do not want to lose hours of submitted tickets if something bad happens. Likewise, we want to provide continuity of operations even if a server goes down. >From what I read in this forum, RT should be fine with the volume assuming a decent server. My concern is more about robustness. Thanks for your comments and suggestions. Thierry