How We Built r/Place
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How We Built r/Place
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Re: How We Built r/Place
#2> We actually had a race condition here that allowed users to place multiple tiles at once. There was no locking around the steps 1-3 so simultaneous tile draw attempts could all pass the check at step 1 and then draw multiple tiles at step 2.
This is why you use a proper database.
I'd probably add a Postgres table to record all user activity, and use that to lock out users for 5 minutes as an initial filter. Have triggers on updates to then feed the rest of the application.
Re: How We Built r/Place
#3> We actually had a race condition here that allowed users to place multiple tiles at once. There was no locking around the steps 1-3 so simultaneous tile draw attempts could all pass the check at step 1 and then draw multiple tiles at step 2. This is why you use a proper database. I'd probably add a Postgres table to record all user activity, and use that to lock out users for 5 minutes as an initial filter. Have tr…
These no-SQL solutions seem shoehorned many times.
Like people decide to use them from the get-go and then come up with a justification.
Re: How We Built r/Place
#4Can someone link to the full resolution final image? Been trying to find it. Thanks!
Re: How We Built r/Place
#5Can someone link to the full resolution final image? Been trying to find it. Thanks!
If you ever want to revisit, it's linked in the right side of the sub.
Re: How We Built r/Place
#6> Users can place one tile every 5 minutes, so we must support an average update rate of 100,000 tiles per 5 minutes (333 updates/s).
It only takes a couple of outliers to bring everything down. I'm not exactly well-versed in defining specs for large scale backend apps (not a back-end engineer) but it seems to me that preparing for the average would not be a wise decision?
For example, designing with an average of a million requests per day in mind would probably fail, since you get most of that traffic during daytime and far more less at the nightly hours.
Could anyone more experienced shed some light?
Re: How We Built r/Place
#7Can someone link to the full resolution final image? Been trying to find it. Thanks!
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Re: How We Built r/Place
#8Re: How We Built r/Place
#9I thought it was interesting that one of their requirements was to provide an API that was easy to use for both bots and visualization tools. I remember reading some speculation when this was running that r/place was intentionally easy to interface with bots, while there were also complaints that the whole thing had been taken over by bots near the end.
Re: How We Built r/Place
#10> We actually had a race condition here that allowed users to place multiple tiles at once. There was no locking around the steps 1-3 so simultaneous tile draw attempts could all pass the check at step 1 and then draw multiple tiles at step 2. This is why you use a proper database. I'd probably add a Postgres table to record all user activity, and use that to lock out users for 5 minutes as an initial filter. Have tr…
At reddit it's much easier for us to stand up a new Cassandra column family than a new postgres table (not saying this is how it should be, but just how it is).
All we needed to do here was add some simple locking and we would have been fine.