While I'd hoped to be able to make the socket client less weird, I
think that this is a nice middle ground in terms of improving
readability and removing the vestigal components without breaking
anything or radically changing the underlying assumptions.
In the future we'd want to have requests be identified by a request
ID, and then we could drop the request tracking logic in the client
entirely, and this is protocol breaking. The alternatives aren't
substantively different than the current implementation.
This change changes the ABCI socket client to allow goroutines to block writing to the internal queue. This has the effect ensuring that callers of the ABCI methods do not error on a full internal queue at the expense of allowing the number of goroutines waiting on this internal queue to grow in an unbounded fashion. This tradeoff seems preferable since it allows callers of the ABCI methods to be certain that a request that was made will reach the application if it is available.
Closes: #7827
This change was initially implemented here: e13b4386ff and never landed on v0.34, only v0.35+
This follows along in the spirit of #7845 but is orthogonal to
removing `CheckTxAsync` (which will come after the previous commit
lands,) so I thought I'd get it out there earlier.
* Rebased and git-squashed the commits in PR #6546
migrate abci to finalizeBlock
work on abci, proxy and mempool
abciresponse, blok events, indexer, some tests
fix some tests
fix errors
fix errors in abci
fix tests amd errors
* Fixes after rebasing PR#6546
* Restored height to RequestFinalizeBlock & other
* Fixed more UTs
* Fixed kvstore
* More UT fixes
* last TC fixed
* make format
* Update internal/consensus/mempool_test.go
Co-authored-by: William Banfield <4561443+williambanfield@users.noreply.github.com>
* Addressed @williambanfield's comments
* Fixed UTs
* Addressed last comments from @williambanfield
* make format
Co-authored-by: marbar3778 <marbar3778@yahoo.com>
Co-authored-by: William Banfield <4561443+williambanfield@users.noreply.github.com>
Our test cases spew a lot of files and directories around $TMPDIR. Make more
thorough use of the testing package's TempDir methods to ensure these are
cleaned up.
In a few cases, this required plumbing test contexts through existing helper
code. In a couple places an explicit path was required, to work around cases
where we do global setup during a TestMain function. Those cases probably
deserve more thorough cleansing (preferably with fire), but for now I have just
worked around it to keep focused on the cleanup.
This change has two main effects:
1. Remove most of the Async methods from the abci.Client interface.
Remaining are FlushAsync, CommitTxAsync, and DeliverTxAsync.
2. Rename the synchronous methods to remove the "Sync" suffix.
The rest of the change is updating the implementations, subsets, and mocks of
the interface, along with the call sites that point to them.
* Fix stringly-typed mock stubs.
* Rename helper method.
This averts a log-after-close issue. We should probably also chase the shutdown
issues, but since ABCI clients should generally only shut down once per process
I don't think this is a real priority, and the trace is hairy.
This continues the push of plumbing contexts through tendermint. I
attempted to find all goroutines in the production code (non-test) and
made sure that these threads would exit when their contexts were
canceled, and I believe this PR does that.
Rework the implementation of event query parsing and execution to
improve performance and reduce memory usage.
Previous memory and CPU profiles of the pubsub service showed query
processing as a significant hotspot. While we don't have evidence that
this is visibly hurting users, fixing it is fairly easy and self-contained.
Updates #6439.
Typical benchmark results comparing the original implementation (PEG) with the reworked implementation (Custom):
```
TEST TIME/OP BYTES/OP ALLOCS/OP SPEEDUP MEM SAVING
BenchmarkParsePEG-12 51716 ns 526832 27
BenchmarkParseCustom-12 2167 ns 4616 17 23.8x 99.1%
BenchmarkMatchPEG-12 3086 ns 1097 22
BenchmarkMatchCustom-12 294.2 ns 64 3 10.5x 94.1%
```
Components:
* Add a basic parsing benchmark.
* Move the original query implementation to a subdirectory.
* Add lexical scanner for Query expressions.
* Add a parser for Query expressions.
* Implement query compiler.
* Add test cases based on OpenAPI examples.
* Add MustCompile to replace the original MustParse, and update usage.
This is a very small change, but removes a method from the
`service.Service` interface (a win!) and forces callers to explicitly
pass loggers in to objects during construction rather than (later)
injecting them. There's not a real need for this kind of lazy
construction of loggers, and I think a decent potential for confusion
for mutable loggers.
The main concern I have is that this changes the constructor API for
ABCI clients. I think this is fine, and I suspect that as we plumb
contexts through, and make changes to the RPC services there'll be a
number of similar sorts of changes to various (quasi) public
interfaces, which I think we should welcome.
The main effect of this change is to flush the socket client and server message
encoding buffers immediately once the message is fully and correctly encoded.
This allows us to remove the timer and some other special cases, without
changing the observed behaviour of the system.
-- Background
The socket protocol client and server each use a buffered writer to encode
request and response messages onto the underlying connection. This reduces the
possibility of a single message being split across multiple writes, but has the
side-effect that a request may remain buffered for some time.
The implementation worked around this by keeping a ticker that occasionally
triggers a flush, and by flushing the writer in response to an explicit request
baked into the client/server protocol (see also #6994).
These workarounds are both unnecessary: Once a message has been dequeued for
sending and fully encoded in wire format, there is no real use keeping all or
part of it buffered locally. Moreover, using an asynchronous process to flush
the buffer makes the round-trip performance of the request unpredictable.
-- Benchmarks
Code: https://play.golang.org/p/0ChUOxJOiHt
I found no pre-existing performance benchmarks to justify the flush pattern,
but a natural question is whether this will significantly harm client/server
performance. To test this, I implemented a simple benchmark that transfers
randomly-sized byte buffers from a no-op "client" to a no-op "server" over a
Unix-domain socket, using a buffered writer, both with and without explicit
flushes after each write.
As the following data show, flushing every time (FLUSH=true) does reduce raw
throughput, but not by a significant amount except for very small request
sizes, where the transfer time is already trivial (1.9μs). Given that the
client is calibrated for 1MiB transactions, the overhead is not meaningful.
The percentage in each section is the speedup for flushing only when the buffer
is full, relative to flushing every block. The benchmark uses the default
buffer size (4096 bytes), which is the same value used by the socket client and
server implementation:
FLUSH NBLOCKS MAX AVG TOTAL ELAPSED TIME/BLOCK
false 3957471 512 255 1011165416 2.00018873s 505ns
true 1068568 512 255 273064368 2.000217051s 1.871µs
(73%)
false 536096 4096 2048 1098066401 2.000229108s 3.731µs
true 477911 4096 2047 978746731 2.000177825s 4.185µs
(10.8%)
false 124595 16384 8181 1019340160 2.000235086s 16.053µs
true 120995 16384 8179 989703064 2.000329349s 16.532µs
(2.9%)
false 2114 1048576 525693 1111316541 2.000479928s 946.3µs
true 2083 1048576 526379 1096449173 2.001817137s 961.025µs
(1.5%)
Note also that the FLUSH=false baseline is actually faster than the production
code, which flushes more often than is required by the buffer filling up.
Moreover, the timer slows down the overall transaction rate of the client and
server, indepenedent of how fast the socket transfer is, so the loss on a real
workload is probably much less.
The code in the Tendermint repository makes heavy use of import aliasing.
This is made necessary by our extensive reuse of common base package names, and
by repetition of similar names across different subdirectories.
Unfortunately we have not been very consistent about which packages we alias in
various circumstances, and the aliases we use vary. In the spirit of the advice
in the style guide and https://github.com/golang/go/wiki/CodeReviewComments#imports,
his change makes an effort to clean up and normalize import aliasing.
This change makes no API or behavioral changes. It is a pure cleanup intended
o help make the code more readable to developers (including myself) trying to
understand what is being imported where.
Only unexported names have been modified, and the changes were generated and
applied mechanically with gofmt -r and comby, respecting the lexical and
syntactic rules of Go. Even so, I did not fix every inconsistency. Where the
changes would be too disruptive, I left it alone.
The principles I followed in this cleanup are:
- Remove aliases that restate the package name.
- Remove aliases where the base package name is unambiguous.
- Move overly-terse abbreviations from the import to the usage site.
- Fix lexical issues (remove underscores, remove capitalization).
- Fix import groupings to more closely match the style guide.
- Group blank (side-effecting) imports and ensure they are commented.
- Add aliases to multiple imports with the same base package name.