Open-source darling MySQL is facing a new uprising within its customer base over plans disclosed this week to reserve some key upcoming features, and their source code, for paying users of its database.

Officials at Sun Microsystems, which acquired MySQL in February, confirmed that new online backup capabilities now under development will be offered only to MySQL Enterprise customers -- not to the much larger number of users of the free MySQL Community edition.

The plan was detailed during meetings at MySQL's annual user conference in Santa Clara, Calif., during which Sun also delayed until late June the release of a MySQL 5.1 upgrade in order to iron out some remaining bugs.

This is the second dust-up between MySQL and its users in the past eight months. Last August, an earlier decision to stop making the MySQL Enterprise source code openly available to users without paid subscriptions drew criticism from some members of the MySQL community.

Red Hat and many other open-source vendors test new features by first offering them to non-paying users, who also get access to the source code for those features.

MySQL's software reportedly is used by tens of millions of individual users, and its corporate customers include Google, Yahoo and some of the most popular Web 2.0 sites. Cheerfully acknowledging in an interview with Computerworld last year that only one in a thousand MySQL users paid for the software, then-CEO Marten Mickos said that the company had no plans to make some of its products and source code proprietary.

"We've had that debate many times," said Mickos, who now is senior vice president of Sun's database group. "I think we might win a few new customers, but we would lose 2 million users. We're not ready for that kind of compromise." He added that other vendors that had built closed-source products on top of open-source software "don't seem successful.

The decision to now withhold some features from the community version caught MySQL loyalists by surprise, and some are accusing MySQL of betraying the community that helped build it up.

"Does not MySQL believe in open source? Or just partially believe?" asked Vadim blog post. Tkachenko, a former MySQL employee who now works as a consultant at Percona, said that while Sun itself is releasing open-source versions of previously proprietary products, MySQL seems to be trying to hide features from the open-source community. "I understand this all is about money, and anyone is free to do with his product anything, but MySQL does not seem [to be] playing [an] open game here," he wrote.

"As before MySQL AB illustrates that they have stopped believing in open source when it becomes time to make money," wrote Lukas Kahwe Smith, another MySQL user, on his blog.

In another blog post, user Paul Saduauskas threatened to abandon MySQL in favour of rival open-source databases in response to the hoarding of features for the enterprise version. For instance, Saduauskas said that the PostgreSQL database is "fast enough these days" and is "much more standards-compliant" than MySQL is.

"Hopefully Sun will see the light, and realize that continuing down this path will destroy MySQL and the community," he wrote. "Free software developers (including myself) are a fickle bunch, and can jump ship or fork a project with startling speed."

In a response to a blog post about the new approach by MySQL consultant Jeremy Cole, Mickos said the move is part of an effort to ensure "that there is a viable revenue-generating business around MySQL."

Mickos also hinted that features initially reserved for paying users may eventually be made freely available, and he noted that there's nothing to stop anyone from developing open-source versions of the online backup capabilities. In addition, he contended that what MySQL is doing is no different from what other open-source database vendors have done with some of their technologies.

Don MacAskill, CEO of SmugMug Inc., an online photo-sharing service that is a paying MySQL customer, defended the new plan as a way to keep companies like his satisfied -- and paying their subscription fees.

"Personally, I think this is awesome," MacAskill blogged. "Don't get me wrong -- I love open source. But let's not forget that MySQL is a business. They have customers, and they have to solve those customers' problems."
That process results in "a virtuous cycle where the community benefits directly as MySQL thrives financially," he added. "In a very real way, without companies like mine, there wouldn't be a new backup tool at all -- let alone the differences this debate is focused on."

But Cole, a former database administrator at Yahoo who now works at consulting firm Proven Scaling, said in his blog post this week that the move could hurt enterprise users just as much as it does non-paying ones.

"The size of the user base for MySQL Enterprise is much smaller than for MySQL Community," Cole wrote. "That means these critical features will be tested by only a few of [MySQL's] customers. So, in effect, they will be giving their paying customers real, true, untested code. How is this supposed to work?"

Even if the plan to restrict some features to MySQL Enterprise users was already in motion before MySQL's acquisition by Sun, the change is in harmony with Sun's need to financially justify the US$1 billion it spent to acquire MySQL, argued an executive from another open-source database vendor.

"As the first major announcement since their acquisition, it's clear that Sun's invisible hand is at work, focused less on the true meaning of open source and more on revenue generation," Deb Woods, vice president of product development at Ingres Corp., said via e-mail. "MySQL's latest move is certainly one that we will not introduce."