fjahr

For discussion of https://github.com/bitcoin/bitcoin/pull/24008/commits/c14ae132c5a5204a9a755c84c6de05fb30459221

Conditions in GetChainstateForNewBlock

• IF1: if(!m_snapshot_chainstate) => use ibd
• IF2: if(m_blockman.LookupBlockIndex(blockhash) == nullptr) => use snapshot
  • This means we use the snapshot chainstate if we have not seen this block’s header yet, implied from it not being in m_block_index
• IF3: if (!m_snapshot_chainstate->m_chain.Contains(pblock))) => use snapshot
  • This means we use the snapshot chainstate if the block header is not part of the current best chain (included in m_chain) which can mean we have not validated the full block yet or the block is not part of the best chain after validation
• FB: fallback => use ibd

fjahr

Theoretical ASMap deployment for v25.0 release

For reference, see the general release schedule of v25.0 here: bitcoin/bitcoin#26549

Tools/Repositories mentioned:

• asmapy
• sipasmap
• kartograf

Steps

fjahr

ASMap in Bitcoin Core releases/ASMap data sources

Background

To get a general overview/refresher of the ASMap project please (re)read the post from Gleb on the Bitmex blog [1]. What is described there is still the status of ASMap file data sources to my knowledge.

Some further questions of mine about the process were discussed in November 2021 in an IRC meeting [2]. It was discussed that fresh ASMap files will be generated for and shipped with every release. The historic files that are part of the releases should be available in a separate repository under the bitcoin core GitHub organization. It was also discussed where the tools used during the release process should be maintained.

Since then, my focus has been on what would be the best possible data sources and quality assurance process for the input data of the ASMap file, i.e., a prefix to AS mapping that most accurately reflect the reality of the internet and that stays up to date for as long as possible.

fjahr

Examples for getting a list of active peer IPs in the bitcoin network

From your own node

Get the list of IPs known to your node and save them to the file peers_ips.txt. Then count how many IPs are in the file.

$ src/bitcoin-cli getnodeaddresses 0 | jq -r '.[] | .address' > peer_ips.txt
$ wc -l peer_ips.txt

fjahr

Good first review label

Goals

• Make it easier for new contributors to start reviewing PRs

How?

• Complexity level low, tentative small change
• Detailed description of the PR background if needed

fjahr

Bitcoin Socratic Seminar in Frankfurt (27.08.2020)

Part of Bitcoin Week. For more information on Bitcoin Socratic Seminars in general, see https://bitdevs.org/ and https://bitdevs.berlin/.

Usually we talk about new topics of the last 4 weeks but since this group is not meeting regularly it will be more of a "best-of" of the last ~2 months. Also, feel free to bring your own topic if you feel something is missing (has to be in line with our general selection guidelines, no promotion of commercial services please). Ideally notify me before we start so I can make time for it or send me a message on twitter (@fjahr).

Security

• Malicious Tor relays changing Bitcoin addresses
• Ledger data breach

fjahr

function f() {
  setTimeout( () => {
    if(document.getElementsByClassName("ajax-pagination-btn").length){
      Array.from(document.getElementsByClassName("ajax-pagination-btn")).forEach(l => l.click());
      f();
    } else {
      console.log("Done");
    }
  }, 1000); // May need to adjust this depending on your internet connection and machine performance
}

fjahr

Debugging Bitcoin Core Workshop

Short link: http://bit.ly/2H2rKjp

Goals of this workshop

• Learn to use GDB/LLDB when you need it
• Practice basic commands
• Drills / Wax on, wax off.
• We stay high level

fjahr

With --enable-debug

$ src/bitcoin-cli getblockchaininfo
{
  "chain": "main",
  "blocks": 220002,
  "headers": 613884,
  "bestblockhash": "00000000000000f8e6ea4282254b6cbc518a519ac7e1de83a8b7f413c16bc2c7",
  "difficulty": 3275464.586565617,

fjahr

This succeeds:

• 50 outputs of 1 BTC in the same destination
• Send 10.5 BTC
• 2 groups are used for the inputs, in total there are 20 inputs

    def test_destination_groupings(self):
        '''
        If a destination has more than 10 outputs, exactly 10 outputs should
        be used when spending from that destination
        '''