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Topic: Alert: chain fork caused by pre-0.8 clients dealing badly with large blocks - page 12. (Read 155564 times)

hero member
Activity: 501
Merit: 500
We need a scheduled hardfork eventually to solve this one for good, yes?

A suggestion: include some of the wishlisted changes in the upcoming fork. Hard forks should be few and far between (ideally: none), so the chance to have one should be exploited to the max.
hero member
Activity: 2086
Merit: 501
★Bitvest.io★ Play Plinko or Invest!
How can we prevent this from happening in the future and is there any other way the average user can contribute to the robustness of bitcoin?
newbie
Activity: 53
Merit: 0
It *was* indirectly because of the size of the block.  Even at 166 bytes each (or whatever the minimum size of transaction), a 250K block cannot contain 1700+ transactions.  And a number of transactions that exceeds the BDB configuration is believed to be the root of the problem.  I know hindsight is 20/20, but I will give the developers credit and assume testing all extremes from 1 really big transaction to many really tiny transactions probably would have been in a formal release cycle.  No such testing was done, chiefly because this was an off the cuff suggestion, not a formal release.
The problem is with the old version, and is a previously unknown bug. Are you saying the developers should have thought to test the old version for an unknown bug before releasing the new version?
It is quite normal, when developing a complex system, that a new release must maintain compatibility with some of the "bugs" that were present in the old release.  I believe the developers of bitcoin follow that philosophy.  By definition, a *unexpected* difference in behavior between the old client and the new client is a bug in the new client.

I believe if the developers had decided to raise the blocksize before releasing 0.8, they may have found this bug during their testing.  The problem is that NO FORMAL TESTING was performed before the lead developer's suggestion was taken to heart by several mining pools.  Don't ask your "customers" to do X, unless you have tested that doing X causes no harm.  As someone else already pointed out on this thread, the development team was well aware that changing to a new database was a possible source of trouble.  I will give the developers credit and assume they tested thoroughly.  So I repeat, if the blocksize had been raised *before* the official release of 0.8, at least there would have been a chance of detecting the difference in behavior, and thus a chance of avoiding this fork.
hero member
Activity: 509
Merit: 564
"In Us We Trust"
newbie
Activity: 53
Merit: 0
It was fascinating to watch the higher block chain continue to build.  Was it ignorance by some large miners?  Or was it an intentional attempt to keep the blockchain forked.
No, it was night. I woke up at 3am thanks to one guy who called me over skype. I have a lot of monitoring scripts which trigger SMS alert when something bad happen on pool, but there was almost no chance to catch this, because the bug wasn't in bitcoind 0.8 used by the pool, but in previous (and still widely spread) bitcoind 0.7.
I include that in "ignorance".  You were ignorant of the situation, else you would have responded.   Smiley  I guess I assumed there would be some sort of "friend net" by which the major mining pools operators would hear of trouble demanding their attention.  Such is the nature of a distributed, volunteer project, eh.

My mining client is configured to print the message that goes to the server when it finds a share.  From the hexadecimal code in the message, I could see the block header's Previous Block field, and I could see my pool was mining the wrong fork.  The next pool I switched to was also mining the wrong fork.  The third pool I tried was mining the correct (now current) fork.
hero member
Activity: 495
Merit: 500
what does (orphaned) mean Huh
hero member
Activity: 868
Merit: 1002
Can we plz go to yellow alert now?
Agreed. Really hoping major selloff does not occur. This issue was handled very effectively and quickly. Hopefully pessimistic btc holders will not go on a selling spree.
I wouldn't worry. Anyone foolish enough to panic sell will find an eager buyer. Every time that happens, the coins move to stronger hands and the market becomes more resistant to that behavior.
legendary
Activity: 1190
Merit: 1001
Can we go to a cornflower blue alert?
member
Activity: 72
Merit: 10
Can we plz go to yellow alert now?
Agreed. Really hoping major selloff does not occur. This issue was handled very effectively and quickly. Hopefully pessimistic btc holders will not go on a selling spree.
hero member
Activity: 509
Merit: 564
"In Us We Trust"
Can we plz go to yellow alert now?

Awww the poor bunny....

look at what the big stupid oracle database did.

someone please comfort the scared little bunny, this is just adorably sad  Sad
hero member
Activity: 496
Merit: 500
It *was* indirectly because of the size of the block.  Even at 166 bytes each (or whatever the minimum size of transaction), a 250K block cannot contain 1700+ transactions.  And a number of transactions that exceeds the BDB configuration is believed to be the root of the problem.  I know hindsight is 20/20, but I will give the developers credit and assume testing all extremes from 1 really big transaction to many really tiny transactions probably would have been in a formal release cycle.  No such testing was done, chiefly because this was an off the cuff suggestion, not a formal release.

The problem is with the old version, and is a previously unknown bug. Are you saying the developers should have thought to test the old version for an unknown bug before releasing the new version?
legendary
Activity: 883
Merit: 1005
Can we plz go to yellow alert now?
newbie
Activity: 53
Merit: 0
This all started when the lead developer issued an "off the cuff" suggestion to enlarge the block size from 250K to 500K.  A miner went the extra step and enlarged the block to 1M, which *should* have been legal.  But there wasn't enough system and integration testing.  [There was *none* as far as I can tell with respect to this suggested change.]  Perhaps the community will learn to avoid untested changes in the future.
It wasn't the size of the block that caused the problem.
It *was* indirectly because of the size of the block.  Even at 166 bytes each (or whatever the minimum size of transaction), a 250K block cannot contain 1700+ transactions.  And a number of transactions that exceeds the BDB configuration is believed to be the root of the problem.  I know hindsight is 20/20, but I will give the developers credit and assume testing all extremes from 1 really big transaction to many really tiny transactions probably would have been in a formal release cycle.  No such testing was done, chiefly because this was an off the cuff suggestion, not a formal release.
hero member
Activity: 868
Merit: 1002
Apparently from what I read, this was handled extremely well. My respect to the devs.
+1
newbie
Activity: 39
Merit: 0
This has been interesting to read.  The problem has almost corrected itself, and may be corrected by the time I press "submit".

Users never needed to downgrade.  Miners didn't really need to downgrade either.  They needed to stop producing very large blocks.  And they needed to be poked to ignore the higher block, temporarily.  [Downgrading accomplishes both, but I doubt that most miners went to that trouble.]


Amazing. So you read this entire thread, came away with zero clue as to what happened, and decided to start preaching to the rest of us?

Maybe try reading it again.
hero member
Activity: 496
Merit: 500
i have send some BTC's from 0,8 client to 0.7

http://blockchain.info/tx-index/59975963/3542ab5bfaf62eb31b5c80d7480e56cc3ab9631046cb21b1ef2b6c091c9906cc


did i losnt my bitcoins ?? it is still unconfirmed Sad

Nope, as long as you didn't double spend against yourself, you will eventually see your transaction confirm. Even if it was in the losing chain, it will get reincorporated into the main chain.
legendary
Activity: 1148
Merit: 1008
If you want to walk on water, get out of the boat
If the problem is solved, remove the red, scary message  Smiley

And great job solving the problem! Bitcoin, finding bugs in the database that not even Oracle know!

Quote
IN 3 hours the price of bitcoins will be around 14 bucks
BUY BUY BUY  Shocked
C'mon, sometime the world stock exchanges have problems too but it is not that when it happens, the world market crash  Smiley

Quote
did i losnt my bitcoins ?? it is still unconfirmed
0 fee, it will be confirmed eventually, just wait!
member
Activity: 76
Merit: 10
i have send some BTC's from 0,8 client to 0.7

http://blockchain.info/tx-index/59975963/3542ab5bfaf62eb31b5c80d7480e56cc3ab9631046cb21b1ef2b6c091c9906cc


did i losnt my bitcoins ?? it is still unconfirmed Sad
hero member
Activity: 495
Merit: 500
I sent myself 2 small payments a while ago and they confirmed,but 29 coin transaction received 5 hours earlier  is still stuck on 0-6.Hopefully  this error gets fixed. Angry
legendary
Activity: 883
Merit: 1005
IN 3 hours the price of bitcoins will be around 14 bucks. Mark my words
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