uPlexa Bridge Daily Limits Optimization

2 min readApr 17, 2021

Hey folks,

We are providing you an update today over the daily-limits for the uPlexa bridge. If you were wondering why limits are in place, it’s because this is a brand new technology and we need to keep all transactios safe!

Today the uPlexa bridge ran into a little snag, but nothing major! Here’s what transpired and how we fixed an issue concerning daily total limits for the uPlexa bridge.

uPlexa bridge batches payments into bUPX using the multiMint function which was created to act in congruence with the transfer_split function within uPlexa wallets. Previously, checking whether we were over the daily limit occured one time per batch. Yesterday, this caused 3x the daily limit to be swapped, as all of which transactions where in one batch (queue). Today, we implemented a per-tx check, rather than per-batch. So, those who got all of your bUPX in one go, lucky you!

Unfortunately, a couple hours after QuantumLeaper had left the office to do some “life stuff”, swaps stopped processing on the uPlexa Bridge. After returning, QL found that the autoSwapper had crashed due to a balance mismatch. If there is a balance mismatch, the autoSwapper fail-safe stops all actions until further reviewed. After digging in, it was found that there were duplicate TX records within the swaps database. Again, not to worry, as the autoSwapper recognized that the balances did not match and did not resume payments. Thus, the database was then backed up, and the duplicate transactions were purged. After purging the duplicate transactions, the balances matched and payments processed successfully.

Root cause analysis:

The root cause of this issue was due to a race condition, since fixed by implementing a cache memory store on transactional processing.

Current Swaps:

At the time of writing, there are 32,321,235.48 ($52,229.83) in pending UPX to bUPX swaps. As our total daily limits still remain at $20,000, this will take ~3 days to clear.

Apologies for the inconvenience.




uPlexa: Incentivizing the mass compute power of IoT devices to form a means of anonymous blockchain payments.