* Updates ADDR_RESPONSE_LIMIT_DENOMINATOR to 4
* Moves logic getting a fraction of Zebra's peers to a method in the address book
* Adds and uses CachedPeerAddrs struct in inbound service
* moves and documents constant
* fixes test
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* updates docs
* renames sanitized_window method
* renames CachedPeerAddrs to CachedPeerAddrResponse
* updates test
* moves try_refresh to per request
* Make unused sanitization method pub(crate)
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* moves CachedPeerAddrResponse to a module
* updates unit test
* fixes unit test
* removes unnecessary condition
* clears cached getaddr response if it can't refresh for over a minute after the refresh time
* tests that inbound service gives out the same addresses for every Peers request before the refresh interval
* Applies suggestion from code review
* fixes doc link
* renames constant
* Fix docs on new constant
* applies suggestion from code review
* uses longer cache expiry time
* Adds code comments
---------
Co-authored-by: teor <teor@riseup.net>
* fix clippy and rustfmt after last releases today
* Ignore clippy::arc_with_non_send_sync false positives in proptest code only
* Remove .cargo/config.toml changes that didn't work
---------
Co-authored-by: teor <teor@riseup.net>
* Adds most_recent_by_ip field to address book
* adds test
* Apply suggestions from code review
* fixes lint
* Updates most_recent_by_ip in .take()
Updates should_update_most_recent_by_ip() and has_active_peer_with_ip to check last_attempt and last_failure times
Renames has_active_peer_with_ip
* Documents that Zebra will not initiate more than 1 outbound connections per IP
* Fixes is_ready_for_connection_attempt_with_ip
Adds test coverage for AttemptPending and Failed
Fixes new_outbound_peer_connections_are_rate_limited proptest
* Applies suggestions from code review.
* Applies suggestions from code review
* Always return true from `is_ready_for_connection_attempt_with_ip` if max_connections_per_ip != 0
* Update max_connections_per_ip config docs
* Warn about invalid config fields and use default values
* Ignores last_attempt and last_failure in is_ready_for_connection_attempt_with_ip
updates test
* Only update most_recent_by_ip if update.last_conn_state is responded.
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* fixes lint
* Update zebra-network/src/address_book.rs
Co-authored-by: teor <teor@riseup.net>
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* Fix Rust syntax
* Fix whitespace
---------
Co-authored-by: teor <teor@riseup.net>
* Rewrite some state cache docs to clarify
* Add a zebra_network::Config.cache_dir for peer address caches
* Add new config test files and fix config test failure message
* Create some zebra-chain and zebra-network convenience functions
* Add methods for reading and writing the peer address cache
* Add cached disk peers to the initial peers list
* Add metrics and logging for loading and storing the peer cache
* Replace log of useless redacted peer IP addresses
* Limit the peer cache minimum and maximum size, don't write empty caches
* Add a cacheable_peers() method to the address book
* Add a peer disk cache updater task to the peer set tasks
* Document that the peer cache is shared by multiple instances unless configured otherwise
* Disable peer cache read/write in disconnected tests
* Make initial peer cache updater sleep shorter for tests
* Add unit tests for reading and writing the peer cache
* Update the task list in the start command docs
* Modify the existing persistent acceptance test to check for peer caches
* Update the peer cache directory when writing test configs
* Add a CacheDir type so the default config can be enabled, but tests can disable it
* Update tests to use the CacheDir config type
* Rename some CacheDir internals
* Add config file test cases for each kind of CacheDir config
* Panic if the config contains invalid socket addresses, rather than continuing
* Add a network directory to state cache directory contents tests
* Add new network.cache_dir config to the config parsing tests
* Ignore out of order Address Book changes, and restructure the function
* Handle concurrent changes using the connection state machine order
* Handle out of order changes correctly
* Pass times through the call stack so they are consistent in tests
* Add time arguments to tests
* Fix tests that were broken by the address order checks
* fastmod wall_ local_ zebra*
* cargo fmt --all
* Fix a bug in the concurrent change check
* Test all the new apply and skip checks for address changes
* Document more edge cases and increase the concurrency time slightly
* Simplify enum ordering matches
* Fix comment typos
Co-authored-by: Arya <aryasolhi@gmail.com>
---------
Co-authored-by: Arya <aryasolhi@gmail.com>
* Add a PeerSocketAddr type which hides its IP address, but shows the port
* Manually replace SocketAddr with PeerSocketAddr where needed
```sh
fastmod SocketAddr PeerSocketAddr zebra-network
```
* Add missing imports
* Make converting into PeerSocketAddr easier
* Fix some unused imports
* Add a canonical_peer_addr() function
* Fix connection handling for PeerSocketAddr
* Fix serialization for PeerSocketAddr
* Fix tests for PeerSocketAddr
* Remove some unused imports
* Fix address book listener handling
* Remove redundant imports and conversions
* Update outdated IPv4-mapped IPv6 address code
* Make addresses canonical when deserializing
* Stop logging peer addresses in RPC code
* Update zebrad tests with new PeerSocketAddr type
* Update zebra-rpc tests with new PeerSocketAddr type
---------
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* Close the new connection if Zebra unexpectedly generates a duplicate random nonce
* Add a missing test module comment
* Avoid peer attacks that replay self-connection nonces to manipulate the nonce set (needs tests)
* Add a test that makes sure network self-connections fail
* Log an info level when self-connections fail (this should be rare)
* Just use plain blocks for mutex critical sections
* Add a missing space
* Implement Display and to_string() for NetworkUpgrade
* Add a progress-bar feature to zebrad
* Add the progress bar writer to the tracing component
* Add a block progress bar transmitter
* Correctly shut down the progress bar, and shut it down on an interrupt
* Make it clearer that the progress task never exits
* Add a config for writing logs to a file
* Add a progress-bar feature to zebra-network
* Add a progress bar for the address book size
* Add progress bars for never attempted and failed peers
* Add an optional limit and label to connection counters
* Add open connection progress bars
* Improve CheckpointList API and CheckpointVerifier debugging
* Add checkpoint index and checkpoint queue progress bars
* Security: Limit the number of non-finalized chains tracked by Zebra
* Make some NonFinalizedState methods available with proptest-impl
* Add a non-finalized chain count progress bar
* Track the last fork height for newly forked chains
* Add a should_count_metrics to Chain
* Add a display method for PartialCumulativeWork
* Add a progress bar for each chain fork
* Add a NonFinalizedState::disable_metrics() method and switch to using it
* Move metrics out of Chain because we can't update Arc<Chain>
* Fix: consistently use best chain order when searching chains
* Track Chain progress bars in NonFinalizedState
* Display work as bits, not a multiple of the target difficulty
* Handle negative fork lengths by reporting "No fork"
* Correctly disable unused fork bars
* clippy: rewrite using `match _.cmp(_) { ... }`
* Initial mempool progress bar implementation
* Update Cargo.lock
* Add the actual transaction size as a description to the cost bar
* Only show mempool progress bars after first activation
* Add queued and rejected mempool progress bars
* Clarify cost note is actual size
* Add tracing.log_file config and progress-bar feature to zebrad docs
* Derive Clone for Chain
* Upgrade to howudoin 0.1.2 and remove some bug workarounds
* Directly call the debug formatter to Display a Network
Co-authored-by: Arya <aryasolhi@gmail.com>
* Rename the address count metric to num_addresses
Co-authored-by: Arya <aryasolhi@gmail.com>
* Simplify reverse checkpoint lookup
Co-authored-by: Arya <aryasolhi@gmail.com>
* Simplify progress bar shutdown code
Co-authored-by: Arya <aryasolhi@gmail.com>
* Remove unused MIN_TRANSPARENT_TX_MEMPOOL_SIZE
* Document that the progress task runs forever
* Fix progress log formatting
* If progress-bar is on, log to a file by default
* Create missing directories for log files
* Add file security docs for running Zebra with elevated permissions
* Document automatic log file, spell progress-bar correctly
---------
Co-authored-by: Arya <aryasolhi@gmail.com>
* adds ValidateBlock request to state
* adds `Request` enum in block verifier
skips solution check for BlockProposal requests
calls CheckBlockValidity instead of Commit block for BlockProposal requests
* uses new Request in references to chain verifier
* adds getblocktemplate proposal mode response type
* makes getblocktemplate-rpcs feature in zebra-consensus select getblocktemplate-rpcs in zebra-state
* Adds PR review revisions
* adds info log in CheckBlockProposalValidity
* Reverts replacement of match statement
* adds `GetBlockTemplate::capabilities` fn
* conditions calling checkpoint verifier on !request.is_proposal
* updates references to validate_and_commit_non_finalized
* adds snapshot test, updates test vectors
* adds `should_count_metrics` to NonFinalizedState
* Returns an error from chain verifier for block proposal requests below checkpoint height
adds feature flags
* adds "proposal" to GET_BLOCK_TEMPLATE_CAPABILITIES_FIELD
* adds back block::Request to zebra-consensus lib
* updates snapshots
* Removes unnecessary network arg
* skips req in tracing intstrument for read state
* Moves out block proposal validation to its own fn
* corrects `difficulty_threshold_is_valid` docs
adds/fixes some comments, adds TODOs
general cleanup from a self-review.
* Update zebra-state/src/service.rs
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* Update zebra-rpc/src/methods/get_block_template_rpcs.rs
Co-authored-by: teor <teor@riseup.net>
* check best chain tip
* Update zebra-state/src/service.rs
Co-authored-by: teor <teor@riseup.net>
* Applies cleanup suggestions from code review
* updates gbt acceptance test to make a block proposal
* fixes json parsing mistake
* adds retries
* returns reject reason if there are no retries left
* moves result deserialization to RPCRequestClient method, adds docs, moves jsonrpc_core to dev-dependencies
* moves sleep(EXPECTED_TX_TIME) out of loop
* updates/adds info logs in retry loop
* Revert "moves sleep(EXPECTED_TX_TIME) out of loop"
This reverts commit f7f0926f4050519687a79afc16656c3f345c004b.
* adds `allow(dead_code)`
* tests with curtime, mintime, & maxtime
* Fixes doc comment
* Logs error responses from chain_verifier CheckProposal requests
* Removes retry loop, adds num_txs log
* removes verbose info log
* sorts mempool_txs before generating merkle root
* Make imports conditional on a feature
* Disable new CI tests until bugs are fixed
* adds support for getpeerinfo RPC
* adds vector test
* Always passes address_book to RpcServer
* Update zebra-network/src/address_book.rs
Co-authored-by: teor <teor@riseup.net>
* Renames PeerObserver to AddressBookPeers
* adds getpeerinfo acceptance test
* Asserts that addresses parse into SocketAddr
* adds launches_lightwalletd field to TestType::LaunchWithEmptyState and uses it from the get_peer_info test
* renames peer_observer mod
* uses SocketAddr as `addr` field type in PeerInfo
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* Move peer address validation into its own module
* Add a network parameter to AddressBook and some MetaAddr methods
* Reject invalid initial peers, and connect to them in preferred order
* Reject Flux/ZelCash and misconfigured Zcash peers
* Prefer canonical Zcash ports
* Make peer_preference into a struct method
* Prefer peer addresses with canonical ports for outbound connections
* Also ignore the Zcash regtest port
* Document where field and variant order is required for correctness
* Use the correct peer count
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* Fix the syntax of links in comments
* Fix a mistake in the docs
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Remove unnecessary angle brackets from a link
* Revert the changes for links that serve as references
* Revert "Revert the changes for links that serve as references"
This reverts commit 8b091aa9fab453e7d3559a5d474e0879183b9bfb.
* Remove `<` `>` from links that serve as references
This reverts commit 046ef25620ae1a2140760ae7ea379deecb4b583c.
* Don't use `<` `>` in normal comments
* Don't use `<` `>` for normal comments
* Revert changes for comments starting with `//`
* Fix some warnings produced by `cargo doc`
* Fix some rustdoc warnings
* Fix some warnings
* Refactor some changes
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Upgrade tracing and related dependencies
```sh
cargo upgrade --workspace
tracing-error
tracing-subscrber
color-eyre
tracing-flame
tracing-journald
sentry
sentry-tracing
metrics
metrics-exporter-prometheus
reqwest
```
* Update duplicate dependency checks
* Enable the tracing/env-filter feature
* Fix type inference for metrics
Manual changes, plus:
```sh
fastmod "as _" "as f64"
```
* Tidy up some unrelated test code
* Update metrics-exporter-prometheus API
And make unused dependencies optional.
* Adjust test regexes to new tracing format
Also fix some regex bugs, and refactor to simplify.
* Disable color-eyre span traces and track caller in release builds
* Add a feature that enables extra debugging in release builds
* Clean up some redundant features
* Increase a test timeout
* Stop holding completed messages until the next inbound message
* Add more info to network message block download debug logs
* Simplify address metrics logs
* Try handling inbound messages as responses, then try as a new request
* Improve address book logging
* Fix a race between the first heartbeat and getaddr requests
* Temporarily reduce the getaddr fanout to 1
* Update metrics when exiting the Connection run loop
* Downgrade some debug logs to trace
* Tweak crawler timings so peers are more likely to be available
* Tweak min peer connection interval so we try all peers
* Let other tasks run between fanouts, so we're more likely to choose different peers
* Let other tasks run between retries, so we're more likely to choose different peers
* Let other tasks run after peer crawler DemandDrop
This makes it more likely that peers will become ready.
* Spawn the address book updater on a blocking thread
* Spawn CandidateSet address book operations on blocking threads
* Replace the PeerSet address book with a metrics watch channel
* Fix comment
* Await spawned address book tasks
* Run the address book update tasks concurrently (except for the mutex)
* Explain an internal-only method better
* Fix a typo
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Refactor the address response limit
* Limit the number of peers in the address book
* Allow changing the address book limit in tests
* Add tests for the address book length limit
* rustfmt
* Stop checking the entire AddressBook for each connection attempt
* Stop redundant peer time checks within the address book
* Stop calling `Instant::now` 3 times for each address book update
* Only get the time once each time an address book method is called
* Update outdated comment
* Use an OrderedMap to efficiently store address book peers
* Add address book order tests
* Implement addr v1 serialization using a separate AddrV1 type
* Remove commented-out code
* Split the address serialization code into modules
* Reorder v1 and in_version fields in serialization order
* Fix a missed search-and-replace
* Explain conversion to MetaAddr
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Rename some methods and constants for clarity
Using the following commands:
```
fastmod '\bis_ready_for_attempt\b' is_ready_for_connection_attempt
# One instance required a tweak, because of the ASCII diagram.
fastmod '\bwas_recently_live\b' has_connection_recently_responded
fastmod '\bwas_recently_attempted\b' was_connection_recently_attempted
fastmod '\bwas_recently_failed\b' has_connection_recently_failed
fastmod '\bLIVE_PEER_DURATION\b' MIN_PEER_RECONNECTION_DELAY
```
* Use `Instant::elapsed` for conciseness
Instead of `Instant::now().saturating_duration_since`. They're both
equivalent, and `elapsed` only panics if the `Instant` is somehow
synthetically generated.
* Allow `Duration32` to be created in other crates
Export the `Duration32` from the `zebra_chain::serialization` module.
* Add some new `Duration32` constructors
Create some helper `const` constructors to make it easy to create
constant durations. Add methods to create a `Duration32` from seconds,
minutes and hours.
* Avoid gossiping unreachable peers
When sanitizing the list of peers to gossip, remove those that we
haven't seen in more than three hours.
* Test if unreachable addresses aren't gossiped
Create a property test with random addreses inserted into an
`AddressBook`, and verify that the sanitized list of addresses does not
contain any addresses considered unreachable.
* Test if new alternate address isn't gossipable
Create a new alternate peer, because that type of `MetaAddr` does not
have `last_response` or `untrusted_last_seen` times. Verify that the
peer is not considered gossipable.
* Test if local listener is gossipable
The `MetaAddr` representing the local peer's listening address should
always be considered gossipable.
* Test if gossiped peer recently seen is gossipable
Create a `MetaAddr` representing a gossiped peer that was reported to be
seen recently. Check that the peer is considered gossipable.
* Test peer reportedly last seen in the future
Create a `MetaAddr` representing a peer gossiped and reported to have
been last seen in a time that's in the future. Check that the peer is
considered gossipable, to check that the fallback calculation is working
as intended.
* Test gossiped peer reportedly seen long ago
Create a `MetaAddr` representing a gossiped peer that was reported to
last have been seen a long time ago. Check that the peer is not
considered gossipable.
* Test if just responded peer is gossipable
Create a `MetaAddr` representing a peer that has just responded and
check that it is considered gossipable.
* Test if recently responded peer is gossipable
Create a `MetaAddr` representing a peer that last responded within the
duration a peer is considered reachable. Verify that the peer is
considered gossipable.
* Test peer that responded long ago isn't gossipable
Create a `MetaAddr` representing a peer that last responded outside the
duration a peer is considered reachable. Verify that the peer is not
considered gossipable.
* Gossip dynamically allocated listener ports to peers
Previously, Zebra would either gossip port `0`, which is invalid, or skip
gossiping its own dynamically allocated listener port.
* Improve "no configured peers" warning
And downgrade from error to warning, because inbound-only nodes are a
valid use case.
* Move random_known_port to zebra-test
* Add tests for dynamic local listener ports and the AddressBook
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Always send our local listener with the latest time
Previously, whenever there was an inbound request for peers, we would
clone the address book and update it with the local listener.
This had two impacts:
- the listener could conflict with an existing entry,
rather than unconditionally replacing it, and
- the listener was briefly included in the address book metrics.
As a side-effect, this change also makes sanitization slightly faster,
because it avoids some useless peer filtering and sorting.
* Skip listeners that are not valid for outbound connections
* Filter sanitized addresses Zebra based on address state
This fix correctly prevents Zebra gossiping client addresses to peers,
but still keeps the client in the address book to avoid reconnections.
* Add a full set of DateTime32 and Duration32 calculation methods
* Refactor sanitize to use the new DateTime32/Duration32 methods
* Security: Use canonical SocketAddrs to avoid duplicate connections
If we allow multiple variants for each peer address, we can make multiple
connections to that peer.
Also make sure sanitized MetaAddrs are valid for outbound connections.
* Test that address books contain the local listener address
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Security: Limit reconnection rate to individual peers
Reconnection Rate
Limit the reconnection rate to each individual peer by applying the
liveness cutoff to the attempt, responded, and failure time fields.
If any field is recent, the peer is skipped.
The new liveness cutoff skips any peers that have recently been attempted
or failed. (Previously, the liveness check was only applied if the peer
was in the `Responded` state, which could lead to repeated retries of
`Failed` peers, particularly in small address books.)
Reconnection Order
Zebra prefers more useful peer states, then the earliest attempted,
failed, and responded times, then the most recent gossiped last seen
times.
Before this change, Zebra took the most recent time in all the peer time
fields, and used that time for liveness and ordering. This led to
confusion between trusted and untrusted data, and success and failure
times.
Unlike the previous order, the new order:
- tries all peers in each state, before re-trying any peer in that state,
and
- only checks the the gossiped untrusted last seen time
if all other times are equal.
* Preserve the later time if changes arrive out of order
* Update CandidateSet::next documentation
* Update CandidateSet state diagram
* Fix variant names in comments
* Explain why timestamps can be left out of MetaAddrChanges
* Add a simple test for the individual peer retry limit
* Only generate valid Arbitrary PeerServices values
* Add an individual peer retry limit AddressBook and CandidateSet test
* Stop deleting recently live addresses from the address book
If we delete recently live addresses from the address book, we can get a
new entry for them, and reconnect too rapidly.
* Rename functions to match similar tokio API
* Fix docs for service sorting
* Clarify a comment
* Cleanup a variable and comments
* Remove blank lines in the CandidateSet state diagram
* Add a multi-peer proptest that checks outbound attempt fairness
* Fix a comment typo
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Simplify time maths in MetaAddr
* Create a Duration32 type to simplify calculations and comparisons
* Rename variables for clarity
* Split a string constant into multiple lines
* Make constants match rustdoc order
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Security: stop gossiping failure and attempt times as last_seen times
Previously, Zebra had a single time field for peer addresses, which was
updated every time a peer was attempted, sent a message, or failed.
This is a security issue, because the `last_seen` time should be
"the last time [a peer] connected to that node", so that
"nodes can use the time field to avoid relaying old 'addr' messages".
So Zebra was sending incorrect peer information to other nodes.
As part of this change, we split the `last_seen` time into the
following fields:
- untrusted_last_seen: gossiped from other peers
- last_response: time we got a response from a directly connected peer
- last_attempt: time we attempted to connect to a peer
- last_failure: time a connection with a peer failed
* Implement Arbitrary and strategies for MetaAddrChange
Also replace the MetaAddr Arbitrary impl with a derive.
* Write proptests for MetaAddr and MetaAddrChange
MetaAddr:
- the only times that get included in serialized MetaAddrs are
the untrusted last seen and responded times
MetaAddrChange:
- the untrusted last seen time is never updated
- the services are only updated if there has been a handshake
When peers ask for peer addresses, add our local listener address to the
set of addresses, sanitize, then truncate. Sanitize shuffles addresses,
so if there are lots of addresses in the address book, our address will
only be sent to some peers.
- stop putting inbound addresses in the address book
- drop address book entries that can't be used for outbound connections
- distinguish between temporary inbound and permanent outbound peer
addresses
- also create variants to handle proxy connections
(but don't use them yet)
- avoid tracking connection state for isolated connections
- document security constraints for the address book and peer set
`sanitize` could be misused in two ways:
* accidentally modifying the addresses in the address book itself
* forgetting to sanitize new fields added to `MetaAddr`
This change prevents accidental modification by taking `&self`, and
explicitly creates a new sanitized `MetaAddr` with all fields listed.
Design:
- Add a `PeerAddrState` to each `MetaAddr`
- Use a single peer set for all peers, regardless of state
- Implement time-based liveness as an `AddressBook` method, rather than
a `PeerAddrState` variant
- Delete `AddressBook.by_state`
Implementation:
- Simplify `AddressBook` changes using `update` and `take` modifier
methods
- Simplify the `AddressBook` iterator implementation, replacing it with
methods that are more obviously correct
- Consistently collect peer set metrics
Documentation:
- Expand and update the peer set documentation
We can optimise later, but for now we want simple code that is more
obviously correct.
* network: move gossiped peer selection logic into address book.
* network: return BoxService from init.
* zebrad: add note on why we truncate thegossiped peer list
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
* Remove unused .rustfmt.toml
Many of these options are never actually loaded by our CI because of a channel
mismatch, where they're not applied on stable but only on nightly (see the logs
from a rustfmt job). This means that we can get different settings when
running `cargo fmt` on the nightly and stable channels, which was causing a CI
failure on this PR. Reverting back to the default rustfmt settings avoids this
problem and keeps us in line with upstream rustfmt. There's no loss to us
since we were using the defaults anyways.
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
The previous implementation failed when timestamps were duplicated between
peers, because there was not a 1-1 relationship between timestamps and peers.
The disconnected_peers() function allows us to prevent duplicate
connections without maintaining shared state between the peerset and the
dial-additional-peers task.
This allows us to hide the `TimestampCollector` and to expose only the
address book data required by the inbound request service. It also lets
us have a common data structure (the `AddressBook`) for collecting peer
information that can be used to manage information that other peers
report to us.