More bug statistics

Last November I put together some simple charts with the information from the weekly bug statistics that are automatically generated for the wikitech-l mailing list. There's now thirty-two weeks of data available, so here are some updated charts.

The distribution of resolution types seems to have stayed more or less the same over time, continuing the pattern seen in the original charts:


However, there are some changes in the other graph, which is based on information about the number of bugs each week. It shows the number of new, reopened, assigned and resolved bugs each week (using the scale on the left) and the total number of open bugs (in blue, using the scale on the right):


While there is still the same rough correlation between the number of new bugs and the number of bugs resolved each week, there is also a steady trend upwards in the total number of open bugs. Indeed, the total has risen nearly 20% since October last year.

So what are the consequences of so many bugs being opened but not dealt with? The following chart, generated by Bugzilla directly, shows the distribution of the "severity" parameter of all currently open bugs:


It shows that three-fifths of open bugs have severity given as "enhancement", essentially meaning that they're feature requests, entered into Bugzilla for tracking purposes, rather than being true bugs. A further 13% are marked "trivial" or "minor", and nearly a quarter "normal"; only 3% are "major".

So while the number of unresolved bugs is steadily rising, most of these are either feature requests or only minor bugs. Still, the backlog is fairly steadily getting worse, a reminder that it's constantly necessary for new volunteer developers to become involved with improving MediaWiki.

Bug statistics

Since the beginning of September, the bug tracker for MediaWiki has been sending weekly updates to the Wikitech-l mailing list, with stats on how many bugs were opened and resolved, the type of resolution, and the top five resolvers for that week. With eleven weeks of data so far, some observations can be made.

The following graph shows the number of new, resolved, reopened and assigned bugs per week (dates given are the starting date for the week). The total number of bugs open that week is shown in blue, and uses the scale to the right of the graph:


The total number of open bugs has been trending upwards, but only marginally, over the past couple of months. It will be interesting to see, with further weekly data, where this trend goes.

It also seems that the number of bugs resolved in any given week tends to go up and down in tandem with the number of new bugs reported in that week. Although there is no data currently available on how quickly bugs are resolved, I would speculate that most of the "urgent" bugs are resolved within the week that they are reported, which would explain the correlation.

Note also the spike in activity in the week beginning 6th October; this was probably the result of the first Bug Monday.

The second graph shows the breakdown of types of bug resolutions:


The distribution seems fairly similar week on week, with most resolutions being fixes. It's interesting to note that regularly around 25% to 35% of bug reports are problematic in some way, whether duplicates or bugs that cannot be reproduced by testers.

The weekly reports are just a taste of the information available about current bugs; see the reports and charts page for much more statistic-y goodness. And kudos to the developers who steadily work away each week to handle bugs!