 Show Posts
|
|
Pages: [1]
|
|
I'm trying to develop a service for bitcoin users and I would like to post in the technical support forum please. Thanks.
|
|
|
|
Hi, I am trying to develop a service for bitcoins, but there are some problems. I use PHP and JSON-RPC and bitcoind. 1. If there is an error in a call to bitcoid/json-rpc, it throws an exception. For example if I try: $bitcoin->getrawtransaction("abcd"); gives: Fatal error: Uncaught exception 'Exception' with message 'Unable to connect to http://xxxx:xxxx@127.0.0.1:8332/' in /.../jsonRPCClient.php:140
Stack trace:
#0 check.php(181): jsonRPCClient->__call('getrawtransacti...', Array)
#1 check.php(181): jsonRPCClient->getrawtransaction('abcd', 1)
#2 {main}
thrown in /.../jsonRPCClient.php on line 140
The same call in the debug window of bitcoin-qt gives: No information available about transaction (code -5) Is it possible to get these errors instead of exceptions? 2. What is a good way to handle blockchain reorganization? If I accept a transaction from user, then the blockchain is reorganized? What info can I get from "bitcoind -blocknotify "cmd""? Does it tell me which blocks are now rejected, or just the hash of the newly accepted block? 3. How can I verify that transactions I receive are "normal" transactions, and reject any "non-normal". I mean, I don't want to accept transaction with locktime, or sequence. I only want normal transaction that I can freely redeem at any time. Is it enough to accept (I mean store in database) only locktime=0 and sequence=2^32-1? Or do I have to check the details of scriptPubKey too? Thanks. |
|
|
|
If more mining rigs use FPGA and ASIC, then those miners will be able to sell for less. So there will be less resistance to a fall in price.
No, miners are always selling for as much as they can, they are not (that) stupid. Yes, they will look for the highest price. But if the price drops (for other reason) ASIC miners will still be able to have profit. ASIC will not cause price drop, but will reduce resistance to price drop, until everyone has ASIC, difficulty is x500 higher, and mining costs are high again as today. x500 from https://en.bitcoin.it/wiki/Mining_hardware_comparison - Mhash/J for GPU is about 2, for ASIC is 1000. At current difficulty a GPU miner cannot profit if price falls below $5.50, but ASIC miner can profit at $0.02 (this is just electricity cost, ignores hardware cost). Look at http://bitcoinx.com/profit/index.php, with difficulty=3million, electricity $0.15/kwh, power 1500W with 1500GH/s for ASIC (eg BFL minirig SC) or 3GH/s for 4xGPU. Good business plan would be - buy BFL ASIC minirig, sell coins at $5, force GPU miners to quit. From http://bitcoinx.com/profit/index.php you profit $40000 in 1 month - time to buy another BFL ASIC. But difficulty might reduce from GPU miners quitting, so maybe you profit even more. Or maybe you cause crash in bitcoin and lose everything :-) Biggest problem: do BFL really have 1.5TH/J hardware for $30k? |
|
|
|
i'm actually loading the blockchain files, them are 2 right? when finished i'm not sure in which directory it belongs... If you download the blockchain file from some source, I mean not through bitcoin client, then you must add commandline option "-rescan" when starting bitcoin.
prompt$ bitcoin-qt -rescan
This way the client to read again each block to see if there are transactions with your addresses. If the wallet.dat already "knows" about all it's transactions, then you don't need -rescan, but if not sure, try it. It takes a few minutes.
is that for windows or linux? i'm using win7 for linux. For windows, should be something similar. Maybe /rescan instead of -rescan, but I don't use windows for years. |
|
|
|
Yeah I think personal greed takes over. If everyone agrees and quits mining, and one person continues, he is one lucky bastard the next day because he just got a lot of bitcoins in one day, lol.
Actually, if all the miners quit mining, but one person continues, they would get approximately the same amount of bitcoins as they normally would have gotten. The difficulty doesn't change, so that miner would still have just as hard of a time solving a block as ever. If he were part of a pool, he likely wouldn't get any coins (but he would get shares). If everyone quits just before the difficulty change he would get bitcoins quicker. I think difficulty reductions are limited to 25% or something. |
|
|
|
Escrows and middlemen have solved the trust issues by being equally responsible for all the transactions.
So what about "trust no one". Maybe doesn't count for escrow agent? |
|
|
|
|
If you download the blockchain file from some source, I mean not through bitcoin client, then you must add commandline option "-rescan" when starting bitcoin.
prompt$ bitcoin-qt -rescan
This way the client to read again each block to see if there are transactions with your addresses. If the wallet.dat already "knows" about all it's transactions, then you don't need -rescan, but if not sure, try it. It takes a few minutes.
|
|
|
|
|
If more mining rigs use FPGA and ASIC, then those miners will be able to sell for less. So there will be less resistance to a fall in price.
|
|
|
|
|
Hi, I joined just now. This message is just for testing.
|
|
|
|
|
