When fetching ledgers, the existing code would isolate the peer
that sent the most useful responses and issue follow up queries
only to that peer.
This commit increases the query aggressiveness, and changes the
mechanism used to select which peers to issue follow-up queries
to so as to more evenly spread the load along those peers which
provided useful responses.
* Abort background path finding when closed or disconnected
* Exit pathfinding job thread if there are no requests left
* Don't bother creating the path find job if there are no requests
* Refactor to remove circular dependency between InfoSub and PathRequest
This commit combines the `apply_mutex` and `read_mutex` into a single `mutex_`
var. This new `mutex_` var is a `shared_mutex`, and most operations only need to
lock it with a `shared_lock`. The only exception is `applyMutex`, which may need
a `unique_lock`.
One consequence of removing the `apply_mutex` is more than one `applyMutex`
function can run at the same time. To help reduce lock contention that a
`unique_lock` would cause, checks that only require reading data are run a
`shared_lock` (call these the "prewriteChecks"), then the lock is released, then
a `unique_lock` is acquired. Since a currently running `applyManifest` may write
data between the time a `shared_lock` is released and the `write_lock` is
acquired, the "prewriteChecks" need to be rerun. Duplicating this work isn't
ideal, but the "prewirteChecks" are relatively inexpensive.
A couple of other designs were considered. We could restrict more than one
`applyMutex` function from running concurrently - either with a `applyMutex` or
my setting the max number of manifest jobs on the job queue to one. The biggest
issue with this is if any other function ever adds a write lock for any reason,
`applyManifest` would not be broken - data could be written between the release
of the `shared_lock` and the acquisition of the `unique_lock`. Note: it is
tempting to solve this problem by not releasing the `shared_mutex` and simply
upgrading the lock. In the presence of concurrently running `applyManifest`
functions, this will deadlock (both function need to wait for the other to
release their read locks before they can acquire a write lock).
This is a refactor aimed at cleaning up and simplifying the existing
job queue.
As of now, all jobs are cancelled at the same time and in the same
way, so this commit removes the per-job cancellation token. If the
need for such support is demonstrated, support can be re-added.
* Revise documentation for ClosureCounter and Workers.
* Simplify code, removing unnecessary function arguments and
deduplicating expressions
* Restructure job handlers to no longer need to pass a job's
handle to the job.
The priority of different types of jobs was set back in the early
days of development, based on insight and observations that don't
necessarily apply any longer.
Specifically, job types used by the server to sync to the network
were being treated as lower priority than client requests, making
it more difficult to regain sync.
This commit adjusts the priority of several jobs and should allow
servers to prioritize resynchronizing to the network over serving
clients.
The existing logic involves every server sending every transaction
that it receives to all its peers (except the one that it received
a transaction from).
This commit instead uses a randomized algorithm, where a node will
randomly select peers to relay a given transaction to, caching the
list of transaction hashes that are not relayed and forwading them
to peers once every second. Peers can then determine whether there
are transactions that they have not seen and can request them from
the node which has them.
It is expected that this feature will further reduce the bandwidth
needed to operate a server.
All uses of beast::Thread were previously removed from the code
base, so beast::Thread is removed. One piece of beast::Thread
needed to be preserved: the ability to set the current thread's
name. So there's now a beast::CurrentThreadName that allows the
current thread's name to be set and returned.
Thread naming is also cleaned up a bit. ThreadName.h and .cpp
are removed since beast::CurrentThreadName does a better job.
ThreadEntry is also removed, but its terminateHandler() is
preserved in TerminateHandler.cpp. The revised terminateHandler()
uses beast::CurrentThreadName to recover the name of the running
thread.
Finally, the NO_LOG_UNHANDLED_EXCEPTIONS #define is removed since
it was discovered that the MacOS debugger preserves the stack
of the original throw even if the terminateHandler() rethrows.
Instead of specifying a static list of trusted validators in the config
or validators file, the configuration can now include trusted validator
list publisher keys.
The trusted validator list and quorum are now reset each consensus
round using the latest validator lists and the list of recent
validations seen. The minimum validation quorum is now only
configurable via the command line.
* Remove ripple::RippleMutex and ripple::RippleRecursiveMutex
and use std::mutex and std::recursive_mutex respectively.
* Use std::lock_guard instead of std::unique_lock when the
additional features of std::unique_lock are not needed.
This gives requests for ledger data (and transaction set data)
from peers a separate job type and prioritizes it appropriately.
Previously it was lumped in with fetch packs which have a low
concurrency limit. This should improve the performance of
retrieving historical information.
Source files are moved between modules, includes changed and added,
and some code rewritten, with the goal of reducing cross-module dependencies
and eliminating cycles in the dependency graph of classes.
* Remove RippleAddress dependency in CKey_test
* ByteOrder.h, Blob.h, and strHex.h are moved to basics/. This makes
the basics/ module fully independent of other ripple sources.
* types/ is merged into protocol/. The protocol module now contains
all primitive types specific to the Ripple protocol.
* Move ErrorCodes to protocol/
* Move base_uint to basics/
* Move Base58 to crypto/
* Remove dependence on Serializer in GenerateDeterministicKey
* Eliminate unity header json.h
* Remove obsolete unity headers
* Remove unnecessary includes
