Node discovery periodically revalidates the nodes in its table by sending PING, checking
if they are still alive. I recently noticed some issues with the implementation of this
process, which can cause strange results such as nodes dropping unexpectedly, certain
nodes not getting revalidated often enough, and bad results being returned to incoming
FINDNODE queries.
In this change, the revalidation process is improved with the following logic:
- We maintain two 'revalidation lists' containing the table nodes, named 'fast' and 'slow'.
- The process chooses random nodes from each list on a randomized interval, the interval being
faster for the 'fast' list, and performs revalidation for the chosen node.
- Whenever a node is newly inserted into the table, it goes into the 'fast' list.
Once validation passes, it transfers to the 'slow' list. If a request fails, or the
node changes endpoint, it transfers back into 'fast'.
- livenessChecks is incremented by one for successful checks. Unlike the old implementation,
we will not drop the node on the first failing check. We instead quickly decay the
livenessChecks give it another chance.
- Order of nodes in bucket doesn't matter anymore.
I am also adding a debug API endpoint to dump the node table content.
Co-authored-by: Martin HS <martin@swende.se>
This PR makes the tool use the --bootnodes list as the input to devp2p crawl.
The flag will take effect if the input/output.json file is missing or empty.
The new flag allows configuring an explicit endpoint which is to be
announced in the DHT. This feature was originally developed for the
discv5 wormhole experiment (#25798), but it's useful in other contexts
as well.
This change updates our urfave/cli dependency to the v2 branch of the library.
There are some Go API changes in cli v2:
- Flag values can now be accessed using the methods ctx.Bool,
ctx.Int, ctx.String, ... regardless of whether the flag is 'local' or
'global'.
- v2 has built-in support for flag categories. Our home-grown category
system is removed and the categories of flags are assigned as part of
the flag definition.
For users, there is only one observable difference with cli v2: flags must now
strictly appear before regular arguments. For example, the following command is
now invalid:
geth account import mykey.json --password file.txt
Instead, the command must be invoked as follows:
geth account import --password file.txt mykey.json
TAP is a text format for test results. Parsers for it are available in many languages,
making it easy to consume. I want TAP output from our protocol tests because the
Hive wrapper around them needs to know about the test names and their individual
results and logs. It would also be possible to just write this info as JSON, but I don't
want to invent a new format.
This also improves the normal console output for tests (when running without --tap).
It now prints -- RUN lines before any output from the test, and indents the log output
by one space.
This adds a test suite for discovery v4. The test suite is a port of the Hive suite for
discovery, and will replace the current suite on Hive soon-ish. The tests can be
run locally with this command:
devp2p discv4 test -remote enode//...
Co-authored-by: Felix Lange <fjl@twurst.com>
This adds an implementation of the current discovery v5 spec.
There is full integration with cmd/devp2p and enode.Iterator in this
version. In theory we could enable the new protocol as a replacement of
discovery v4 at any time. In practice, there will likely be a few more
changes to the spec and implementation before this can happen.
This adds an implementation of node discovery via DNS TXT records to the
go-ethereum library. The implementation doesn't match EIP-1459 exactly,
the main difference being that this implementation uses separate merkle
trees for tree links and ENRs. The EIP will be updated to match p2p/dnsdisc.
To maintain DNS trees, cmd/devp2p provides a frontend for the p2p/dnsdisc
library. The new 'dns' subcommands can be used to create, sign and deploy DNS
discovery trees.
* p2p/discover: export Ping and RequestENR
These two are useful for checking the status of a node.
* cmd/devp2p: add devp2p debug tool
This is a new tool for debugging p2p issues. It supports a few
basic tasks for now, but many more things can and will be added
in the near future.
devp2p enrdump -- prints ENRs readably
devp2p discv4 ping -- checks if a node is up
devp2p discv4 requestenr -- gets a node's record
devp2p discv4 resolve -- finds a node through the DHT
