Bitcoin Forum
April 18, 2014, 09:04:56 AM *
News: Due to the OpenSSL heartbleed bug, changing your forum password is recommended.
 
   Home   Help Search Donate Login Register  
Pages: [1] 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
  Print  
Author Topic: Alert: chain fork caused by pre-0.8 clients dealing badly with large blocks  (Read 85655 times)
Pieter Wuille
Hero Member
*****
Offline Offline

Activity: 938


View Profile WWW

Ignore
March 12, 2013, 01:29:57 AM
 #1

Hello everyone,

there is an emergency right now: the block chain has split between 0.7+earlier and 0.8 nodes. I'll explain the reasons in a minute, but this is what you need to know now:
  • After a discussion on #bitcoin-dev, it seems trying to get everyone on the old chain again is the least risky solution.
  • If you're a miner, please do not mine on 0.8 code. Stop, or switch back to 0.7. BTCGuild is switching to 0.7, so the old chain will get a majority hash rate soon.
  • If you're a merchant: please stop processing transactions until the chains converge.
  • If you're on 0.7 or older, the client will likely tell you that you need to upgrade. Do not follow this advise - the warning should go away as soon as the old chain catches up.
  • If you are not a merchant or a miner, don't worry.

The original post lacked info for "regular users".  Here it is:

(1) If you are a "regular user" (not a miner), the best thing is to do nothing and wait a couple hours.
(2) If you are a "regular user", upgrading, downgrading, whining, FUD, etc, will make no difference.  Only miners have an incentive to do anything.  Otherwise, it doesn't matter which version you are running.
(3) Regardless of who you are, your transactions are not dead, your coins are not lost.  They will just temporarily be held up.  If you sent a transaction within the last few hours, it may take a few more hours before it's sorted out.
(4) If you insist on processing transactions right now it's probably best to wait 30+ confirmations.  It's just due diligence though ... an attacker would still need a tremendous amount of mining power, quick thinking, and a victim willing to part with a lot of BTC.
(5) By tomorrow this will be in the past and everything will appear to be normal again.  If you slept through this, you'd never know that anything happend (except for the price drop).

Let me reiterate, your coins are not at risk, your transactions are not lost.  It'll just take some time for the network to "iron itself out."  Everything will be okay.

aka sipa, core dev team

Tips and donations: 1KwDYMJMS4xq3ZEWYfdBRwYG2fHwhZsipa
1397811896
Hero Member
*
Offline Offline

Posts: 1397811896

View Profile Personal Message (Offline)

Ignore
1397811896
Reply with quote  #2

1397811896
Report to moderator
1397811896
Hero Member
*
Offline Offline

Posts: 1397811896

View Profile Personal Message (Offline)

Ignore
1397811896
Reply with quote  #2

1397811896
Report to moderator
GAWMiners.com
ASIC Scrypt Miners
Guaranteed Satisfaction + Same-Day Shipping For FREE!
Simply Enter "freeshipping" at checkout

Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1397811896
Hero Member
*
Offline Offline

Posts: 1397811896

View Profile Personal Message (Offline)

Ignore
1397811896
Reply with quote  #2

1397811896
Report to moderator
1397811896
Hero Member
*
Offline Offline

Posts: 1397811896

View Profile Personal Message (Offline)

Ignore
1397811896
Reply with quote  #2

1397811896
Report to moderator
1397811896
Hero Member
*
Offline Offline

Posts: 1397811896

View Profile Personal Message (Offline)

Ignore
1397811896
Reply with quote  #2

1397811896
Report to moderator
1397811896
Hero Member
*
Offline Offline

Posts: 1397811896

View Profile Personal Message (Offline)

Ignore
1397811896
Reply with quote  #2

1397811896
Report to moderator
Pieter Wuille
Hero Member
*****
Offline Offline

Activity: 938


View Profile WWW

Ignore
March 12, 2013, 01:30:26 AM
 #2

And now a more elaborate explanation:

0.7 and older nodes use BDB for storing the blockchain databases. It seems this database has a limit on the size of the modification it can make atomically to the database. With the larger blocks of the past days, it seems to have triggered the limit. The result is that 0.7 (by default, it can be tweaked manually) will not accept "too large" blocks (we don't yet know what exactly causes it, but it is very likely caused by many transactions in the block). Specifically, block
000000000000015c50b165fcdd33556f8b44800c5298943ac70b112df480c023 (height=225430) with >1700 transactions.

However. 0.8 (which uses a different database system) has no such limit, and happily accepts the block. As the majority of the hash power was on 0.8, the longest chain ended up using this block, which is not accepted by older nodes.

The solution is to (for now) go back to the old chain, which has block 00000000000001c108384350f74090433e7fcf79a606b8e797f065b130575932 at height 225430.

aka sipa, core dev team

Tips and donations: 1KwDYMJMS4xq3ZEWYfdBRwYG2fHwhZsipa
kokojie
Hero Member
*****
Offline Offline

Activity: 882


tblob.org


View Profile

Ignore
March 12, 2013, 01:31:57 AM
 #3

wow WTF? how did this even happen, a fork due to bug?

If my post has been helpful, send me some love -> BTC: 1kokojUapmWqCqPw3Ch2rjcVh57tJEzka | PPC: PDyXAgA8eH47gokVW6zVZPSuu15aao5nZF | LTC: LRDpNJM5nkXFBDoxWRCk5hicvT7TrXQZ3c
The Big List of Bitcoin | My reputation | Free 20GB cloud storage from copy.com
bitlybit
Newbie
*
Offline Offline

Activity: 14


View Profile

Ignore
March 12, 2013, 01:33:45 AM
 #4

WTF BITCOIN PROTOCOL COMPROMISED???
kokojie
Hero Member
*****
Offline Offline

Activity: 882


tblob.org


View Profile

Ignore
March 12, 2013, 01:34:43 AM
 #5

I think what everyone wants to know is, are my coins safe? or am I holding useless 0.8 forked chain coins?

If my post has been helpful, send me some love -> BTC: 1kokojUapmWqCqPw3Ch2rjcVh57tJEzka | PPC: PDyXAgA8eH47gokVW6zVZPSuu15aao5nZF | LTC: LRDpNJM5nkXFBDoxWRCk5hicvT7TrXQZ3c
The Big List of Bitcoin | My reputation | Free 20GB cloud storage from copy.com
grue
Staff
Hero Member
*****
Offline Offline

Activity: 1036


It is pitch black. You are likely to be eaten by a grue.


View Profile

Ignore
March 12, 2013, 01:35:22 AM
 #6

WTF BITCOIN PROTOCOL COMPROMISED???
EVERYBODY PANIC, SELL SELL SELL

since i'm such a nice guy, i'll buy your bitcoins for $20

1ELvnrA6PhUyDBS6iR25K1Xx4xXL6VMfJX
mccorvic
Hero Member
*****
Offline Offline

Activity: 504



View Profile

Ignore
March 12, 2013, 01:35:48 AM
 #7

I think what everyone wants to know is, are my coins safe? or am I holding useless 0.8 forked chain coins?

This needs to be answered please.

Offering Video/Audio Editing Services since 2011 - https://bitcointalk.org/index.php?topic=77932.0
pizzaman1337
Jr. Member
*
Offline Offline

Activity: 37


View Profile

Ignore
March 12, 2013, 01:36:32 AM
 #8

Great, so, as an end user, if we made a transaction recently, how can we tell which chain it was on?

If we made a transaction on the "new" chain and the "old" chain becomes the "main" chain, I suppose that means we'd have our bitcoins back?

This could result in disaster for transactions happening right now that will no longer be valid in the future... let's hope the exchange rate lives through this.

P.S. Which chain is blockchain.info showing?

(I just saw an urgent error message through the 0.8 client).
str4wm4n
Hero Member
*****
Offline Offline

Activity: 840


View Profile

Ignore
March 12, 2013, 01:36:56 AM
 #9


The-Real-Link
Hero Member
*****
Offline Offline

Activity: 527



View Profile

Ignore
March 12, 2013, 01:37:02 AM
 #10

Just was updating to 0.8 and noticed this.  Should we revert back to 0.7?

Oh Loaded, who art up in Mt. Gox, hallowed be thy name!  Thy dollars rain, thy will be done, on BTCUSD.  Give us this day our daily 10% 30%, and forgive the bears, as we have bought their bitcoins.  And lead us into quadruple digits
fcmatt
Hero Member
*****
Offline Offline

Activity: 882


View Profile

Ignore
March 12, 2013, 01:37:15 AM
 #11

This is going to be on every nerd news website in 24 hours. What a black eye. A few people can stop bitcoin from functioning properly and not even mean to do it.
Technomage
Hero Member
*****
Offline Offline

Activity: 952


www.bittiraha.fi


View Profile WWW

Ignore
March 12, 2013, 01:37:39 AM
 #12

Coins are safe, but the current value in them is not. This will have consequences.

Check out BTC Store - Superior Bitcoin Webstore
qnfauf
Newbie
*
Offline Offline

Activity: 20


View Profile

Ignore
March 12, 2013, 01:38:03 AM
 #13

I just got here after receiving the "urgent" message from the client. I'm a bit confused. I really hope it didn't cause major problems.
grantbdev
Sr. Member
****
Offline Offline

Activity: 291



View Profile

Ignore
March 12, 2013, 01:40:21 AM
 #14

As a user, what should I do? Should I run my 0.8 node or not? Should I revert to an older version and then run node?

Don't use BIPS!
nelisky
Hero Member
*****
Offline Offline

Activity: 1218


View Profile

Ignore
March 12, 2013, 01:40:32 AM
 #15

Anything with more than 11 confirmations (at block 225446) is safe, anything with less may or may not be but all transactions will be retried so bar intended harm there should be no issue for users.

Just don't trust coins with less than 11 confirmations at this point, better yet, don't use your client for the next few hours at all and everything will come back to normality.

we measure long periods of time in bitcoin blocks, and short ones in vodka tonics
DividendRippler  | DICEonCRACK | The Amazing Anonymous Bitcoin Lottery
100x
Sr. Member
****
Offline Offline

Activity: 378


Seek the truth


View Profile

Ignore
March 12, 2013, 01:41:15 AM
 #16

Anything with more than 11 confirmations (at block 225446) is safe, anything with less may or may not be but all transactions will be retried so bar intended harm there should be no issue for users.

Just don't trust coins with less than 11 confirmations at this point, better yet, don't use your client for the next few hours at all and everything will come back to normality.

Ok this doesn't sound so bad. I was a pretty nervous for a second.
kokojie
Hero Member
*****
Offline Offline

Activity: 882


tblob.org


View Profile

Ignore
March 12, 2013, 01:42:12 AM
 #17

Coins are safe, but the current value in them is not. This will have consequences.

Right now I don't understand how can coins be safe if transaction was made on the 0.8 blockchain? I'm hoping for a detailed official answer from the devs.

If my post has been helpful, send me some love -> BTC: 1kokojUapmWqCqPw3Ch2rjcVh57tJEzka | PPC: PDyXAgA8eH47gokVW6zVZPSuu15aao5nZF | LTC: LRDpNJM5nkXFBDoxWRCk5hicvT7TrXQZ3c
The Big List of Bitcoin | My reputation | Free 20GB cloud storage from copy.com
vdragon
SCAMMER
Full Member
*****
Offline Offline

Activity: 196



View Profile WWW

Ignore
March 12, 2013, 01:42:21 AM
 #18

Revert to 0.7 and all ok

My USB Erupter GROUP BUY https://bitcointalk.org/index.php?topic=252180.0

Hungary (south) based trader - accepting/sending bank transfers, also willing to meet in person
FreedomCoin
Sr. Member
****
Offline Offline

Activity: 322


Freedom to choose


View Profile

Ignore
March 12, 2013, 01:42:27 AM
 #19

great.... just did a transaction a couple hours ago.
nelisky
Hero Member
*****
Offline Offline

Activity: 1218


View Profile

Ignore
March 12, 2013, 01:42:32 AM
 #20

SELLING BITCOINS PM ME

PLEASE don't trade with anyone offering good deals right now Smiley There is a very good chance they are trying to take advantage of the chain fork.

IF YOU ARE NOT MINING just go do something else for a while!

we measure long periods of time in bitcoin blocks, and short ones in vodka tonics
DividendRippler  | DICEonCRACK | The Amazing Anonymous Bitcoin Lottery
Pages: [1] 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!