For testing, I'm running a private chain on my laptop. I've loaded a contract and I'm simulating a heavy load on my geth instance by submitting 500 transactions. All the transactions are submitted over ~15 mins or so but while the transactions are coming in mining grinds to a halt and no new blocks are created. It doesn't seem to matter if I'm using miner.start(1) in the geth javascript console or ethminer -C -t 1 to start ethminer in a different process.

All the transactions are happening under the same address so it's not like the miner has a hard decision when it comes to picking what transactions go in the next block. It just has to handle the nonces in order. Eventually mining picks back up again but that can take 20 mins before it happens.

If it matters, I start geth v1.7.1 with the following flags:

geth --networkid 3141 --rpc --rpcapi "db,eth,net,web3,miner" --rpcport "8545" --rpccorsdomain "*" --datadir "~/eth/data" --port "30303" --nat "any" --identity "MyNode-1" --rpcaddr "" --gasprice 0

geth doesn't print out any errors. Why does mining stop while a large number of transactions are being received?

1 Answer 1


Unsure of this specific issue you are having with geth. However, I would suggest you use TestRPC and truffle to instantly send a lot of tests. You can set the block speed to 15 seconds or so to simulate the actual Ethereum chain as well. I have noticed a lot more buggy behavior with setting up private geth chains than just using TestRPC.

Hopefully this can get you back up and running!

  • TestRPC was unreliable. It seemed that only about 50% of the events I had written up would fire. The code definitely ran, I could see side effects showing that it succeeded, but I need events to be reliable. Oct 6, 2017 at 20:44
  • Ah, yeah event catching isn't quite supported in TestRPC. You can either replicate the events with a console.log() or you can add an assert(false) at the end of your test block to "fail" the test, and subsequently display all of the events. See this answer for more: ethereum.stackexchange.com/questions/15674/…
    – Alex
    Oct 6, 2017 at 20:49

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