Extremely high bitcoind getblocktemplate latency

[lenny_]

Hi guys,
I have priority issue with bitcoind latency and p2pool running with it. p2pool link: lenny.dnsd.me:9332

I have dedicated hardware for running bitcoind 24/7 node and p2pool with it. That's small server based on AMD APU A10 + SSD, was working nicely for months, till yesterday.

My bitcoind node is literally flooded by hoax transactions, like this:
https://blockchain.info/tx/7227c9d392166fdcd917f39da2def36bcf69b437d90e349d73a48952c0fbdd69
https://blockchain.info/tx/292d1d7ff7ece8eb67b4bf3c2f523736679c616fce8216bf37ac23edec6e0e03

1 single transaction, nice miner fee included (1.46 USD actually), but it have over two thousands outputs and 100 KB in size! It's like a fishhook, whoever will take it, will loose seconds of latency.

Bitcoind latency is at ~ 4s right now, for months it was at 0.3s. About 18 hours ago my latency went extremely high up to 7s and till then, network is under attack of these hoax transactions. Exactly same problem has been reported by my collegues at forum.bitcoin.pl. They showed be their stats and same latency issues (bitcoind latency at 3s or worse, like in my case).
Latency that high makes mining on my local p2pool node unprofitable.

My bitcoin.conf:

Code:

(...)
maxconnections=30
blockmaxsize=500000
mintxfee=0.00005

How to filter these transactions?  

[zvs]

Hi guys,
I have priority issue with bitcoind latency and p2pool running with it. p2pool link: lenny.dnsd.me:9332

I have dedicated hardware for running bitcoind 24/7 node and p2pool with it. That's small server based on AMD APU A10 + SSD, was working nicely for months, till yesterday.

My bitcoind node is literally flooded by hoax transactions, like this:
https://blockchain.info/tx/7227c9d392166fdcd917f39da2def36bcf69b437d90e349d73a48952c0fbdd69
https://blockchain.info/tx/292d1d7ff7ece8eb67b4bf3c2f523736679c616fce8216bf37ac23edec6e0e03

1 single transaction, nice miner fee included (1.46 USD actually), but it have over two thousands outputs and 100 KB in size! It's like a fishhook, whoever will take it, will loose seconds of latency.

Bitcoind latency is at ~ 4s right now, for months it was at 0.3s. About 18 hours ago my latency went extremely high up to 7s and till then, network is under attack of these hoax transactions. Exactly same problem has been reported by my collegues at forum.bitcoin.pl. They showed be their stats and same latency issues (bitcoind latency at 3s or worse, like in my case).
Latency that high makes mining on my local p2pool node unprofitable.

My bitcoin.conf:

Code:

(...)
maxconnections=30
blockmaxsize=500000
mintxfee=0.00005

How to filter these transactions?  

blockmaxsize 500kb would limit transaction max size to 50kb, wouldnt it?  so those transactions wouldnt even be included in your block?

nm, it'd limit it to 100kb.

so those 100kb transactions i see would be included

you could lower your maxblocksize to something lower =p

[Syke]

Wow, that is one very bad transaction.

[Syke]

Code:

blockmaxsize=250000

I'm going to try this. I can't allow those monster transactions.

[Mike Hearn]

A quick hack would be to adjust this line:

static const unsigned int MAX_STANDARD_TX_SIZE = MAX_BLOCK_SIZE_GEN/5;

and increase the 5 to something bigger, like 15. This is less harmful than reducing the max block size.

However, the real fix is to profile bitcoind and find out where it's spending all its time. It shouldn't take multiple seconds to format a block, that implies poor algorithmic complexity in some part of CreateBlock (which wouldn't surprise me at all and someone probably already knows where the issues are). It'd be much better to find out what's going on there and just fix it.

[wtogami]

Use bitcoin-0.8.2-rc1.  The dust protection will reject transactions like those you linked.

[Syke]

Use bitcoin-0.8.2-rc1.  The dust protection will reject transactions like those you linked.

8.2rc1 helps a little, but whatever transactions are still floating around are causing significant performance issues to gtblocktemplate.

[furball]

Check out the p2pool thread (https://bitcointalk.org/index.php?topic=18313.0) for a great solution to this from user Prattler...worked for me.

[Syke]

Check out the p2pool thread (https://bitcointalk.org/index.php?topic=18313.0) for a great solution to this from user Prattler...worked for me.

Yes, the settings suggested solved my performance issues.

blockmaxsize=250000 # default: 250000
blockprioritysize=27000 # default: 27000
mintxfee=0.0002 # default: 0.0001
minrelaytxfee=0.0002 # default: 0.0001

[lenny_]

I compiled Bitcoin version v0.8.2rc1-2-gf7f9403-beta and changed settings in bitcoin.conf to these above. Will see how it goes.

[Subo1977]

Check out the p2pool thread (https://bitcointalk.org/index.php?topic=18313.0) for a great solution to this from user Prattler...worked for me.

Yes, the settings suggested solved my performance issues.

blockmaxsize=250000 # default: 250000
blockprioritysize=27000 # default: 27000
mintxfee=0.0002 # default: 0.0001
minrelaytxfee=0.0002 # default: 0.0001

From 0.8.2 The fee values  must be in satoshi

[Prattler]

Code:

blockmaxsize=250000 # default: 250000
blockprioritysize=27000 # default: 27000
mintxfee=0.0002 # default: 0.0001
minrelaytxfee=0.0002 # default: 0.0001

From 0.8.2 The fee values  must be in satoshi

You are incorrect. Money amounts need to be as floats in BTC.

Code:

    if (mapArgs.count("-minrelaytxfee"))
    {
        int64 n = 0;
        if (ParseMoney(mapArgs["-minrelaytxfee"], n) && n > 0)
            CTransaction::nMinRelayTxFee = n;
    }

ParseMoney parses strings, but only accepts float representations in BTC, like "0.0005". "50000" will get parsed as 50000 BTC.
See https://github.com/bitcoin/bitcoin/blob/master/src/util.cpp#L417. Will edit if someone corrects me.

[lenny_]

Code:

Linux 3.2.0-4-amd64 x86_64 GNU/Linux
Description:    Debian GNU/Linux 7.0 (wheezy)
Current version: Bitcoin version v0.8.2rc3-2-g09e437b-beta

p2pool Bitcoind GetBlockTemplate Latency from last 24hours:

Code:

0.241s

I am using now default values in bitcoin.conf, no tweaking at all. Looks like new bitcoind version from git solved all issues

[Pieter Wuille]

0.8.2rc2 and above have a patch that makes getblocktemplate significantly faster (I've seen a factor 10 in some cases).

[lenny_]

0.8.2rc2 and above have a patch that makes getblocktemplate significantly faster (I've seen a factor 10 in some cases).

That's true, like it was in my case. From couple of seconds it went down to 0.21s (24h avg), with default settings.