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Topic: Feathercoin - The Miner Update - Hard Fork Block 87948 (Read 2269 times)

hero member
Activity: 617
Merit: 531
Agreed. That is why the block depth is set to 3 when ACP went live rather than 0 based on feedback from technical users in the crowd. This allows some natural reorgs.
3 is too little. PPC and NVC the both uses 6 as depth for PoS blocks, for example. Just compare the targets spacing and block depth... 10min vs. 2.5min && 6 vs. 3.

We are now in a good position to increase the depth. The threat of 51% attacks seems to be reduced now, our difficulty swings are much less we are not seeing the drop off in hash power we saw before. I will bring this up on the Feathercoin forum to get feedback. Balthazar you are very welcome on our forums, we need you as an informed critic Smiley

https://forum.feathercoin.com

How many forks can this coin survive ?

So far each fork has made Feathercoin better, stronger and more resillient. The first fork was because we faced the fact that Litecoin's difficulty adjust takes its hashpower for granted, this fork aims to keep the hashpower up by reducing the swings in difficulty and it reduces the effects of Time Warp attacks.
sr. member
Activity: 341
Merit: 250
How many forks can this coin survive ?
legendary
Activity: 3108
Merit: 1358
Agreed. That is why the block depth is set to 3 when ACP went live rather than 0 based on feedback from technical users in the crowd. This allows some natural reorgs.
3 is too little. PPC and NVC the both uses 6 as depth for PoS blocks, for example. Just compare the targets spacing and block depth... 10min vs. 2.5min && 6 vs. 3.
hero member
Activity: 938
Merit: 1000
www.multipool.us
Are you sure?
Yep. I think that immediate check pointing policy is evil.

Agreed. That is why the block depth is set to 3 when ACP went live rather than 0 based on feedback from technical users in the crowd. This allows some natural reorgs.

After updating.  They were the first two blocks found after we updated.

Can you get me the times and block numbers?

I would like to find out why this did not work.

Feathercoin version v0.6.4.4 (2013-09-19 10:40:03 -0700)
Startup time: 09/30/13 06:42:48
[...]
ThreadRPCServer method=submitblock
ERROR: AcceptBlock() : rejected by synchronized checkpoint
ERROR: ProcessBlock() : AcceptBlock FAILED
[...]
trying connection 195.59.191.91:9336 lastseen=2.1hrs
SetBestChain: new best=96756968b3c40a36bd2d  height=88291  work=36701685832636670  date=09/30/13 17:22:21
[...]
ThreadRPCServer method=submitblock
ERROR: AcceptBlock() : rejected by synchronized checkpoint
ERROR: ProcessBlock() : AcceptBlock FAILED
Flushed 11448 addresses to peers.dat  95ms
connection timeout
trying connection 98.180.48.36:9336 lastseen=13.3hrs
received block f9f880425fe123ef8908
SetBestChain: new best=f9f880425fe123ef8908  height=88387  work=36774223244962492  date=09/30/13 21:33:26
SetBestChain: 21 of last 100 blocks above version 1
ProcessBlock: ACCEPTED


legendary
Activity: 2590
Merit: 2154
Welcome to the SaltySpitoon, how Tough are ya?
Unstickied due to fork date being reached, good luck guys  Smiley
hero member
Activity: 617
Merit: 531
Are you sure?
Yep. I think that immediate check pointing policy is evil.

Agreed. That is why the block depth is set to 3 when ACP went live rather than 0 based on feedback from technical users in the crowd. This allows some natural reorgs.

After updating.  They were the first two blocks found after we updated.

Can you get me the times and block numbers?

I would like to find out why this did not work.
legendary
Activity: 3108
Merit: 1358
Are you sure?
Yep. I think that immediate check pointing policy is evil.

The advanced checkpointing has been running since August, you should have noticed any problems like that ages ago.
Not everybody does review of the debug.log file for reject reason. In fact, only a few people does this.

I am inclined to think it was something else.
Maybe. But immediate check pointing would cause such events too. That's why such policy shouldn't be used for the regular operation.
hero member
Activity: 938
Merit: 1000
www.multipool.us
So I basically got 2 orphans in a row is what you're saying?

You said those blocks got orphaned after updating but were those blocks minted before you updated or after?

Blocks found on the old chain will get orphaned by the new fork. If anyone wants to continue using 0.6.4.3 they would need to set ACP to advisory.

After updating.  They were the first two blocks found after we updated.
hero member
Activity: 617
Merit: 531
So I basically got 2 orphans in a row is what you're saying?

You said those blocks got orphaned after updating but were those blocks minted before you updated or after?

Blocks found on the old chain will get orphaned by the new fork. If anyone wants to continue using 0.6.4.3 they would need to set ACP to advisory.
hero member
Activity: 938
Merit: 1000
www.multipool.us
You can't fix this. This message means that another block is already accepted by network and successfully checkpointed. It seems that blockchain is too fast for the current checkpoints implementation/settings. You can switch it into advisory mode to prevent such events in the future.

But it's better to change checkpoints interval setting to 6-12 blocks.

So I basically got 2 orphans in a row is what you're saying?
erk
hero member
Activity: 826
Merit: 500
You can't fix this. This message means that another block is already accepted by network and successfully checkpointed. It seems that blockchain is too fast for the current checkpoints implementation/settings. You can switch it into advisory mode to prevent such events in the future.

But it's better to change checkpoints interval setting to 6-12 blocks.

Are you sure? The advanced checkpointing has been running since August, you should have noticed any problems like that ages ago. I am inclined to think it was something else.

legendary
Activity: 3108
Merit: 1358
You can't fix this. This message means that another block is already accepted by network and successfully checkpointed. It seems that blockchain is too fast for the current checkpoints implementation/settings. You can switch it into advisory mode to prevent such events in the future.

But it's better to change checkpoints interval setting to 6-12 blocks.
hero member
Activity: 938
Merit: 1000
www.multipool.us
After updating, two blocks Multipool found were rejected with the following error:

ThreadRPCServer method=submitblock
ERROR: AcceptBlock() : rejected by synchronized checkpoint
ERROR: ProcessBlock() : AcceptBlock FAILED

What is the fix for this?
full member
Activity: 146
Merit: 100
Just let this piece of shit coin die already.

Survival is the best form of revenge... hmm that gives me an idea.
hero member
Activity: 798
Merit: 1000
‘Try to be nice’
Just read the whole things from start to finish on the FTC forum .

as you know i'm not a holder of FTC but i think these implementations help the FTC community -

particularly the 504 averaging window and .25 damping

in conjunction with the shortening of the time regarding the "Time warp" flaw. 

as this can help sure up security which ultimately supports confidence to the degree that you can control that aspect.

so good work.  
aa
hero member
Activity: 544
Merit: 500
Litecoin is right coin
Just let this piece of shit coin die already.
hero member
Activity: 617
Merit: 531
I would love to hear how you're going to reduce the effectiveness of the TW Exploit and which one?

Either you're vulnerable to the exploit or you're not, there is no middle ground.


~BCX~

We experienced attacks where Feathercoin blocks were being created two hours into the future. This is the most that the protocol will tolerate and is the default of Bitcoin which has 12 blocks in that time period. We have 12 blocks in a 30 minute period and our code as been adjusted to reject blocks outside of that time period. So the attackers can still swing out time but not by as much.

With adjusts every 126 blocks (5.25 hours) having attackers swing our time by two hours would be a huge problem so we had to limit this in some way.
erk
hero member
Activity: 826
Merit: 500


I would love to hear how you're going to reduce the effectiveness of the TW Exploit and which one?

Either you're vulnerable to the exploit or you're not, there is no middle ground.


~BCX~
Read the source code and you might learn something.

full member
Activity: 178
Merit: 100
This webpage is not available  (https://www.feathercoin.com/)
hero member
Activity: 938
Merit: 1000
www.multipool.us
Perhaps loyal miners would have been a better term.

In short, when the diff swings up 41% the hashrate drops to ~3Gh/s. The LOYAL miners, rather than hop to the next most profitable coin stick around and mine at a higher diff for 2+ days to bring the diff back down. Then when the diff does swing down by 41%, all the multipools and profiteers swing their miners back to FTC, the hashrate jumps to ~10Gh/s and so the good times (low diff) only lasts for 8 hours before swinging up again.

This update will stop the 41% bounce and limit it to 9%. There will be swings still of course but hopefully the effect will be reduced. Simples.

Of course, if you are not a loyal miner, you may not see the benefits, possibly the opposite but we're all about looking after the loyal guys in the community. Grin

That is all.

By profiteers you mean those guys who saved the coin from 51% attack back by switching to FTC when the diff dropped a couple months ago?
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