Site Blog

The Macbot And Doovoo Unvaulting

On May 1, the Macbot and Doovoo were unvaulted and available in the Cash Shop Park. Whenever a rerelease occurs, the species population is allowed to double at most and no more. This is in the interest of protecting creature rarities and their values. This past unvaulting, the Macbot and Doovoo were limited to 35 creatures each. However, due to site lag and the server being overwhelmed with requests all at once, a total of 90 Macbots and 100 Doovoos were obtained in this past rerelease cycle (in 2022).

We sincerely apologize for this. This was not supposed to happen. It was not because we were attempting to sell more creatures than allowed as a cash grab or because the Cash Shop was incorrectly configured. Never before has an unvaulting generated so much interest and traffic at the site. These "traffic surges" are difficult to test for in development environments alone. They are unique scenarios that happen live on the site and then have to be analyzed and fixed after they happen.

Now, why did this happen and what is Egg Cave doing to prevent this from happening again?

What Happened

This unvaulting generated an enormous amount of traffic at Egg Cave. Many users were attempting to buy the Macbot and Doovos at once. Here's an example of what occurs with site lag.

• 30 users submit a request to buy a Macbot or Doovoo at the same time, but only 10 are available
• The server is overwhelmed with these requests
• As the server processes these requests all at once, the server thinks that there are 0 Macbots or Doovos that have been bought, because when the requests were submitted, there were only 0 Macbots or Doovoos bought
• The server isn't aware that 29 other people are waiting in line with you
• Thinking the server needs to "catch up," it oversells the creatures and fulfills all 30 creatures at once

What Has Changed

In order to prevent this from happening again, we have implemented something called mutex locks when purchasing Cash Shop creatures. Mutex (MUtual EXclusion) locks are a programming concept that force the server to handle requests on a first-come, first-serve basis; the server will actually reject other incoming requests if they're occurring at the same time.

What this means: In future Cash Shop rereleases, customers will begin seeing a "Server is busy" error message if the server rejects your request to buy a Cash Shop creature. This message means somebody else beat you to it in that particular timing window to buy a creature, but that there may still be other stock available. A "Server is busy" error doesn't necessarily mean the creature is sold out already, it means that you need to try your request again.

Why wasn't it configured this way to begin with?

In general, servers actually do handle incoming requests on a first-come, first-serve basis. Mutex locks are generally not required to enforce this. Mutex locks are something that are applied in special cases and scenarios. This is obviously a scenario where they need to be applied. The change above has been implemented.

What about the supply of Macbots and Doovoos?

We sincerely apologize that more Macbots and Doovoos were sold than what was allowed. In terms of retroactively correcting the amount released, we find it particularly cruel to remove Macbots and Doovoos from players' accounts that already feel that these creatures are already theirs—even with a refund. Some players have already traded or begun auctions with their new creatures, which would lead to a messy, disastrous domino effect of corrections (what if you're already traded for a Macbot or Doovoo that would be retroactively removed, due to no fault of your own?).

If you've obtained a Macbot and/or Doovoo during this unvaulting, it's yours. Based on the fix that we've implemented above, it should not happen again.