## Problem Fix https://github.com/neondatabase/neon/issues/7003. Fix https://github.com/neondatabase/neon/issues/6982. Currently, neon extension is only upgraded when new compute spec gets applied, for example, when creating a new role or creating a new database. This also resolves `neon.lfc_stat` not found warnings in prod. ## Summary of changes This pull request adds the logic to spawn a background thread to upgrade the neon extension version if the compute is a primary. If for whatever reason the upgrade fails, it reports an error to the console and does not impact compute node state. This change can be further applied to 3rd-party extension upgrades. We can silently upgrade the version of 3rd party extensions in the background in the future. Questions: * Does alter extension takes some kind of lock that will block user requests? * Does `ALTER EXTENSION` writes to the database if nothing needs to be upgraded? (may impact storage size). Otherwise it's safe to land this pull request. Signed-off-by: Alex Chi Z <chi@neon.tech>
Compute node tools
Postgres wrapper (compute_ctl) is intended to be run as a Docker entrypoint or as a systemd
ExecStart option. It will handle all the Neon specifics during compute node
initialization:
compute_ctlaccepts cluster (compute node) specification as a JSON file.- Every start is a fresh start, so the data directory is removed and initialized again on each run.
- Next it will put configuration files into the
PGDATAdirectory. - Sync safekeepers and get commit LSN.
- Get
basebackupfrom pageserver using the returned on the previous step LSN. - Try to start
postgresand wait until it is ready to accept connections. - Check and alter/drop/create roles and databases.
- Hang waiting on the
postmasterprocess to exit.
Also compute_ctl spawns two separate service threads:
compute-monitorchecks the last Postgres activity timestamp and saves it into the sharedComputeNode;http-endpointruns a Hyper HTTP API server, which serves readiness and the last activity requests.
If AUTOSCALING environment variable is set, compute_ctl will start the
vm-monitor located in [neon/libs/vm_monitor]. For VM compute nodes,
vm-monitor communicates with the VM autoscaling system. It coordinates
downscaling and requests immediate upscaling under resource pressure.
Usage example:
compute_ctl -D /var/db/postgres/compute \
-C 'postgresql://cloud_admin@localhost/postgres' \
-S /var/db/postgres/specs/current.json \
-b /usr/local/bin/postgres
Tests
Cargo formatter:
cargo fmt
Run tests:
cargo test
Clippy linter:
cargo clippy --all --all-targets -- -Dwarnings -Drust-2018-idioms
Cross-platform compilation
Imaging that you are on macOS (x86) and you want a Linux GNU (x86_64-unknown-linux-gnu platform in rust terminology) executable.
Using docker
You can use a throw-away Docker container (rustlang/rust image) for doing that:
docker run --rm \
-v $(pwd):/compute_tools \
-w /compute_tools \
-t rustlang/rust:nightly cargo build --release --target=x86_64-unknown-linux-gnu
or one-line:
docker run --rm -v $(pwd):/compute_tools -w /compute_tools -t rust:latest cargo build --release --target=x86_64-unknown-linux-gnu
Using rust native cross-compilation
Another way is to add x86_64-unknown-linux-gnu target on your host system:
rustup target add x86_64-unknown-linux-gnu
Install macOS cross-compiler toolchain:
brew tap SergioBenitez/osxct
brew install x86_64-unknown-linux-gnu
And finally run cargo build:
CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_LINKER=x86_64-unknown-linux-gnu-gcc cargo build --target=x86_64-unknown-linux-gnu --release