Google's effort to speed the pace of Web browsing quickly aggravated some early users, who say that the software is delivering them Web pages under other users' logins and breaking Web applications.
Google Inc.'s Web Accelerator application, launched as a test last Wednesday, uses a combination of local and server-based caching and preloading of Web pages to more quickly serve Web pages to a user's browser. Google's servers, in many ways, act as an intermediary between Websites and a user's browser.
But Google's approach has had some unintended consequences. Google officials Friday confirmed that the company was aware of as many as five sites where Web Accelerator was returning users cached pages under other people's user names.
The company has stopped caching pages from those sites, said Marissa Mayer, Google's director of consumer Web.
Users of some smaller Web forum sites have complained in online postings that they began receiving Web pages which displayed other people's user names after downloading Web Accelerator. The forum site, Somethingawful.com, was among those warning its users to avoid Web Accelerator because of reports that pages from other users' logins were exposed.
"It is an unfortunate problem, but it looks worse than it is," Mayer said. "We are caching those pages on the server side with the user name on them…You see it, but it's important to point out that you are not logged in as user and you do not have the session cookies needed to perform operations as [that] user."
Mayer said the problem stemmed from the way some sites have implemented their HTTP cache-control headers, which provide information such as language preferences to a browser. Google uses those headers to determine whether a page is meant for an individual user, in which case it would not live on its servers, Mayer said.
Google plans to notify the Webmasters of the affected sites about the need to fix their cache-control headers as well as work on a solution within Web Accelerator, Mayer said.
Web Accelerator already prevented secure sites using the HTTPS protocol, such as online banking and Email sites, from being cached.
Web Accelerator's problems appear to extend beyond forum sites, though. Web-based software developer 37Signals LLC began blocking the program after discovering that it was initiating links which performed critical functions, such as account deletions, on 37Signal's Web applications.
A few users complained about deleted accounts on 37Signals's Basecamp and Backpack applications, and the company traced the problem to Web Accelerator, said 37Signals President Jason Fried. To make matters worse, the problem occurred the same week that the Chicago-based company launched Backpack, a personal-information management application.
"It was serious enough to frighten us, since we had just released a product and it coincided with Google's release," said Fried, who first wrote about the issue in his Weblog. "We became aware of the Web Accelerator issue, and within 30 minutes of figuring it out we instituted a block."
As for Web Accelerator's impact on Web applications, Mayer initially said that most of the reports she had seen appeared to be unsubstantiated. When informed about 37Signals' problems, she said that it is possible that some sites are not complying with a Web standard used by Web Accelerator.
Web Accelerator ignores links where a question mark appears before the URL string in the HTML code. A question mark is usually included in a string to indicate personally identifiable information such as a user ID and would typically be used in a link that performs a function like a deletion, Mayer said.
"The product is in beta," Mayer said. "It could be that our assumption around the question mark and the way sites comply with the standard is incorrect. If that is the case, then we'll have to redesign the prefetch algorithm."
Fried acknowledged that the applications do not conform to all standards. For example, functions such as a deletion technically should be handled with buttons rather than links, he said.
Google needs to recognize, however, that many sites use methods that vary from standards, he said.
"To me, the real test here is not so much that Google may have made mistake but how they respond to it," Fried said. "Are they going to call it a mistake or blame everyone else to [make them] build products the way they should be built in a perfect world?"
For other users, Web Accelerator has caused a number of unwanted changes to their Web browsing.
Mike Rumble, a Web programmer at U.K.-based Lawton Communications Group Ltd., said he downloaded Web Accelerator on Thursday and soon noticed that about one out of every 20 Websites were failing to load. Instead, he was redirected to an error page from Web Accelerator, prompting him to try again or to search on Google.
Rumble faced more trouble when he visited his Web-based Email account from Apple Computer Inc.'s .Mac service. He was continuously logged out of the account, something he blamed on Web Accelerator's preloading of pages.
"After signing in it became impossible to get any use out of the service, as every click would lead back to a sign-in page," Rumble said in an e-mail interview. "It appears that the Web Accelerator's prefetching mechanism was signing me out of the service as soon as I had signed in, by 'clicking' on the sign-out link and killing my session."
Rumble, who regularly tries out new software for his office, said he decided to disable Web Accelerator because he feared that it could also wreak havoc on his company's Web-based content management system.
"Google Web Accelerator appears to be a poorly executed, potentially destructive product," he said.
Similar sentiments to Rumble's have been shared in blog postings and online forums across the Web, though other users have said that they are finding that Web Accelerator is saving them time in their Web browsing.
To Mayer, part of the backlash against Web Accelerator likely is a result of Google sitting in the middle between users' browsers and Websites.
By caching Web pages on Google's servers, Web Accelerator is following caching methods already in use by ISPs and by many corporate firewalls, Mayer said. But Google is making that activity more visible to users, who often are not aware that their employers or ISP may be serving them earlier versions of a Web page.
"It does break the paradigm of how people are used to browsing," Mayer said. "It does change the experience slightly in little ways, and it's worth the tradeoff."
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