Files
neon/pageserver/Cargo.toml
Arpad Müller 045bc6af8b Add new compaction abstraction, simulator, and implementation. (#6830)
Rebased version of #5234, part of #6768

This consists of three parts:

1. A refactoring and new contract for implementing and testing
compaction.

The logic is now in a separate crate, with no dependency on the
'pageserver' crate. It defines an interface that the real pageserver
must implement, in order to call the compaction algorithm. The interface
models things like delta and image layers, but just the parts that the
compaction algorithm needs to make decisions. That makes it easier unit
test the algorithm and experiment with different implementations.

I did not convert the current code to the new abstraction, however. When
compaction algorithm is set to "Legacy", we just use the old code. It
might be worthwhile to convert the old code to the new abstraction, so
that we can compare the behavior of the new algorithm against the old
one, using the same simulated cases. If we do that, have to be careful
that the converted code really is equivalent to the old.

This inclues only trivial changes to the main pageserver code. All the
new code is behind a tenant config option. So this should be pretty safe
to merge, even if the new implementation is buggy, as long as we don't
enable it.

2. A new compaction algorithm, implemented using the new abstraction.

The new algorithm is tiered compaction. It is inspired by the PoC at PR
#4539, although I did not use that code directly, as I needed the new
implementation to fit the new abstraction. The algorithm here is less
advanced, I did not implement partial image layers, for example. I
wanted to keep it simple on purpose, so that as we add bells and
whistles, we can see the effects using the included simulator.

One difference to #4539 and your typical LSM tree implementations is how
we keep track of the LSM tree levels. This PR doesn't have a permanent
concept of a level, tier or sorted run at all. There are just delta and
image layers. However, when compaction starts, we look at the layers
that exist, and arrange them into levels, depending on their shapes.
That is ephemeral: when the compaction finishes, we forget that
information. This allows the new algorithm to work without any extra
bookkeeping. That makes it easier to transition from the old algorithm
to new, and back again.

There is just a new tenant config option to choose the compaction
algorithm. The default is "Legacy", meaning the current algorithm in
'main'. If you set it to "Tiered", the new algorithm is used.

3. A simulator, which implements the new abstraction.

The simulator can be used to analyze write and storage amplification,
without running a test with the full pageserver. It can also draw an SVG
animation of the simulation, to visualize how layers are created and
deleted.

To run the simulator:

    cargo run --bin compaction-simulator run-suite

---------

Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
2024-02-27 17:15:46 +01:00

104 lines
3.0 KiB
TOML

[package]
name = "pageserver"
version = "0.1.0"
edition.workspace = true
license.workspace = true
[features]
default = []
# Enables test-only APIs, incuding failpoints. In particular, enables the `fail_point!` macro,
# which adds some runtime cost to run tests on outage conditions
testing = ["fail/failpoints"]
[dependencies]
anyhow.workspace = true
arc-swap.workspace = true
async-compression.workspace = true
async-stream.workspace = true
async-trait.workspace = true
byteorder.workspace = true
bytes.workspace = true
camino.workspace = true
camino-tempfile.workspace = true
chrono = { workspace = true, features = ["serde"] }
clap = { workspace = true, features = ["string"] }
const_format.workspace = true
consumption_metrics.workspace = true
crc32c.workspace = true
crossbeam-utils.workspace = true
either.workspace = true
flate2.workspace = true
fail.workspace = true
futures.workspace = true
git-version.workspace = true
hex.workspace = true
humantime.workspace = true
humantime-serde.workspace = true
hyper.workspace = true
itertools.workspace = true
leaky-bucket.workspace = true
md5.workspace = true
nix.workspace = true
# hack to get the number of worker threads tokio uses
num_cpus = { version = "1.15" }
num-traits.workspace = true
once_cell.workspace = true
pin-project-lite.workspace = true
postgres.workspace = true
postgres_backend.workspace = true
postgres-protocol.workspace = true
postgres-types.workspace = true
rand.workspace = true
regex.workspace = true
scopeguard.workspace = true
serde.workspace = true
serde_json = { workspace = true, features = ["raw_value"] }
serde_path_to_error.workspace = true
serde_with.workspace = true
signal-hook.workspace = true
smallvec = { workspace = true, features = ["write"] }
svg_fmt.workspace = true
sync_wrapper.workspace = true
tokio-tar.workspace = true
thiserror.workspace = true
tokio = { workspace = true, features = ["process", "sync", "fs", "rt", "io-util", "time"] }
tokio-epoll-uring.workspace = true
tokio-io-timeout.workspace = true
tokio-postgres.workspace = true
tokio-stream.workspace = true
tokio-util.workspace = true
toml_edit = { workspace = true, features = [ "serde" ] }
tracing.workspace = true
url.workspace = true
walkdir.workspace = true
metrics.workspace = true
pageserver_api.workspace = true
pageserver_compaction.workspace = true
postgres_connection.workspace = true
postgres_ffi.workspace = true
pq_proto.workspace = true
remote_storage.workspace = true
storage_broker.workspace = true
tenant_size_model.workspace = true
utils.workspace = true
workspace_hack.workspace = true
reqwest.workspace = true
rpds.workspace = true
enum-map.workspace = true
enumset = { workspace = true, features = ["serde"]}
strum.workspace = true
strum_macros.workspace = true
[dev-dependencies]
criterion.workspace = true
hex-literal.workspace = true
tokio = { workspace = true, features = ["process", "sync", "fs", "rt", "io-util", "time", "test-util"] }
[[bench]]
name = "bench_layer_map"
harness = false
[[bench]]
name = "bench_walredo"
harness = false