Files
neon/safekeeper/Cargo.toml
Vlad Lazar 8b18d8b31b safekeeper: add global disk usage utilization limit (#12605)
N.B: No-op for the neon-env.

## Problem

We added a per-timeline disk utilization protection circuit breaker,
which will stop the safekeeper from accepting more WAL writes if the
disk utilization by the timeline has exceeded a configured limit. We
mainly designed the mechanism as a guard against WAL upload/backup bugs,
and we assumed that as long as WAL uploads are proceeding as normal we
will not run into disk pressure. This turned out to be not true. In one
of our load tests where we have 500 PGs ingesting data at the same time,
safekeeper disk utilization started to creep up even though WAL uploads
were completely normal (we likely just maxed out our S3 upload bandwidth
from the single SK). This means the per-timeline disk utilization
protection won't be enough if too many timelines are ingesting data at
the same time.

## Summary of changes

Added a global disk utilization protection circuit breaker which will
stop a safekeeper from accepting more WAL writes if the total disk usage
on the safekeeper (across all tenants) exceeds a limit. We implemented
this circuit breaker through two parts:

1. A "global disk usage watcher" background task that runs at a
configured interval (default every minute) to see how much disk space is
being used in the safekeeper's filesystem. This background task also
performs the check against the limit and publishes the result to a
global atomic boolean flag.
2. The `hadron_check_disk_usage()` routine (in `timeline.rs`) now also
checks this global boolean flag published in the step above, and fails
the `WalAcceptor` (triggers the circuit breaker) if the flag was raised.

The disk usage limit is disabled by default.
It can be tuned with the `--max-global-disk-usage-ratio` CLI arg.

## How is this tested?

Added integration test
`test_wal_acceptor.py::test_global_disk_usage_limit`.

Also noticed that I haven't been using the `wait_until(f)` test function
correctly (the `f` passed in is supposed to raise an exception if the
condition is not met, instead of returning `False`...). Fixed it in both
circuit breaker tests.

---------

Co-authored-by: William Huang <william.huang@databricks.com>
2025-07-16 14:43:17 +00:00

92 lines
2.4 KiB
TOML

[package]
name = "safekeeper"
version = "0.1.0"
edition = "2024"
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"]
benchmarking = []
[dependencies]
async-stream.workspace = true
anyhow.workspace = true
byteorder.workspace = true
bytes.workspace = true
camino.workspace = true
camino-tempfile.workspace = true
chrono.workspace = true
clap = { workspace = true, features = ["derive"] }
crc32c.workspace = true
fail.workspace = true
hex.workspace = true
humantime.workspace = true
http.workspace = true
hyper0.workspace = true
itertools.workspace = true
jsonwebtoken.workspace = true
futures.workspace = true
once_cell.workspace = true
parking_lot.workspace = true
pageserver_api.workspace = true
postgres-protocol.workspace = true
pprof.workspace = true
rand.workspace = true
regex.workspace = true
reqwest = { workspace = true, features = ["json"] }
rustls.workspace = true
scopeguard.workspace = true
serde.workspace = true
serde_json.workspace = true
smallvec.workspace = true
strum.workspace = true
strum_macros.workspace = true
thiserror.workspace = true
tikv-jemallocator.workspace = true
tokio = { workspace = true, features = ["fs"] }
tokio-io-timeout.workspace = true
tokio-postgres.workspace = true
tokio-rustls.workspace = true
tokio-tar.workspace = true
tokio-util = { workspace = true }
tracing.workspace = true
url.workspace = true
metrics.workspace = true
pem.workspace = true
postgres_backend.workspace = true
postgres_ffi.workspace = true
postgres_ffi_types.workspace = true
postgres_versioninfo.workspace = true
pq_proto.workspace = true
remote_storage.workspace = true
safekeeper_api.workspace = true
safekeeper_client.workspace = true
sha2.workspace = true
sd-notify.workspace = true
storage_broker.workspace = true
tokio-stream.workspace = true
http-utils.workspace = true
utils.workspace = true
wal_decoder.workspace = true
env_logger.workspace = true
nix.workspace = true
workspace_hack.workspace = true
[dev-dependencies]
criterion.workspace = true
itertools.workspace = true
walproposer.workspace = true
rand.workspace = true
desim.workspace = true
tracing.workspace = true
tracing-subscriber = { workspace = true, features = ["json"] }
[[bench]]
name = "receive_wal"
harness = false
required-features = ["benchmarking"]