Testnet difficulty calculation changes, to take effect Mar 15 2014

[khalahan]

No description provided.

[dthorpe]

How to test this prior to 3/15? If I build this and fire up -testnet, will it just find new nodes with the right version and carry on?

[dthorpe]

I've pulled this changeset into my local branch and rebuilt namecoin-qt to version 0.3.73. I deleted \users\userid\appdata\namecoin* to force a fresh start. Running namecoin-qt -testnet on two machines seems to connect to IRC and find peers ok, but the network sync gets stuck at block 2039 on both test machines. Is this expected?

[khalahan]

No, this isn't expected, how many connections do you have ?

Try adding : -addnode=94.23.252.190
Or even -connect=94.23.252.190
(try also with an empty blockchain if it isn't sufficient)

[dthorpe]

I deleted the testnet blockchain and restarted with your -addnode. Saw 6 peers very quickly, whereas I was only seeing 2 before.

Blocks received raced up to 2015 within a few minutes, then goes quiet. Shut down namecoin, restart, no change - 2015 blocks, 7 connections.

[dthorpe]

This looks suspicious, from the debug.log file:

sending getdata: block 00000001136199e20959
sending getdata: block 00000007d0ac1effeb03
sending: getdata (18003 bytes) 
trying connection 203.219.186.92:18334 lastseen=-1.0hrs lasttry=-387295.6hrs
received: version (85 bytes)
Added time data, samples 3, offset -1 (+0 minutes)
sending: verack (0 bytes) 
sending: getaddr (0 bytes) 
version message: version 32464, blocks=34714
received: verack (0 bytes)
sending: addr (31 bytes) 
AddPortMapping(18334, 18334, 192.168.2.106) failed with code 718 (ConflictInMappingEntry)
received: block (215 bytes)
received block 00000000b9e4132e1a80
  nActualTimespan = 10212459  before bounds
GetNextWorkRequired RETARGET
nTargetTimespan = 1209600    nActualTimespan = 4838400
Before: 1d07fff8  00000007fff80000000000000000000000000000000000000000000000000000
After:  1d1fffe0  0000001fffe00000000000000000000000000000000000000000000000000000
ERROR: AcceptBlock() : incorrect proof of work
ERROR: ProcessBlock() : AcceptBlock FAILED
received: block (215 bytes)
received block 0000000068bbeec63cf2
ProcessBlock: ORPHAN BLOCK, prev=00000000b9e4132e1a80
sending: getblocks (741 bytes) 
received: block (215 bytes)
received block 00000000c44da0632fd7
ProcessBlock: ORPHAN BLOCK, prev=0000000068bbeec63cf2
received: block (215 bytes)
received block 00000000360575869f3b
ProcessBlock: ORPHAN BLOCK, prev=00000000c44da0632fd7

Those ERROR lines about incorrect proof of work... and then a bunch of orphan blocks reported afterwards... is this a fork in the blockchain?

[dthorpe]

Any ideas on this? None of my namecoin instances is successfully sync'ing the blockchain on testnet. Syncing on regular blockchain works fine.

[khalahan]

Thank you for the report dthorpe.
I suspect this is due to this commit : 98d070614bc492ae767112e1c61d368f0abc2440.

Can you try a "git revert 98d070614bc492ae767112e1c61d368f0abc2440" and restart namecoind ?
I'll do some tests on my side too.

[khalahan]

I've tested with "git revert 98d0706" and the blockchain has been downloaded until last block.
I've updated the merge request and removed the commit 98d0706.

[dthorpe]

Yes, reverting 98d0706 fixed the testnet sync issue for me.

Thanks!