GenTarkin wrote:Chris Sokolowski wrote:Does the "old work" apply to the merge-mined coins? We do need to send work refreshes to prevent miners from disconnecting, and we will send stale merge-mined work while the primary coins is still valid so that we don't cause the miner to restart.
You asking me? I have no way of knowing.
All I know is last night I watched the pool set my worker(pool webgui) to LTC from a different coin, yet my Titan was stuck on the old coin for minutes and never went to LTC. Then the pool worker switched to a diff coin and finally my Titan switched to the matching coin.
It happens often. Same example as in the OP.
When this happens, bfgminer always states "pool x is issuing work for old block" ... it rarely states "pool x caught up to current block" in these cases.
Could you try to confirm if the following happened:
1. You were assigned to a coin with a long block time, like litecoins
2. A very profitable coin came up, so you switched to that coin for a few seconds until the next block was found
3. That coin is no longer more profitable than the coin with a long block time, like litecoins, so you switched back
My current theory is that the miners think that the block which you switched back to is stale because the difficult coin height is usually lower than the block height of the easy network. The block isn't stale; there were no blocks found since the last switch, so it's still valid and it is the most profitable work available. But the miner decides that, because this would never happen if you were mining a single coin, the pool is incorrectly configured and incorrectly takes matters into its own hands, wasting effort.
Is that what is happening? If so, could you modify your firmware to account for the situation when the same block is resent to the miner after a block in the middle?