158d1bbbb4
Previously, 'zenith init' would initialize a PostgreSQL cluster with "initdb -D tmp", creating the temp cluster under current directory. It moves the 'tmp' directory under the correct snapshot directory in the zenith repository after that, but if something goes wrong in initdb, or in the steps that follow, it could leave behind the 'tmp' directory under current dir. Better to create the temporary directory under the repository directory to begin with, as ".zenith/tmp".
Zenith
Zenith substitutes PostgreSQL storage layer and redistributes data across a cluster of nodes
Running local installation
- Build zenith and patched postgres
git clone --recursive https://github.com/libzenith/zenith.git
cd zenith
make
- Start pageserver and postggres on top of it (should be called from repo root):
# Create ~/.zenith with proper paths to binaries and data
# Later that would be responsibility of a package install script
>./target/debug/zenith init
# start pageserver
> ./target/debug/zenith pageserver start
Starting pageserver at '127.0.0.1:64000'
# create and configure postgres data dir
> ./target/debug/zenith pg create
Creating new postgres: path=/Users/user/code/zenith/tmp_check_cli/compute/pg1 port=55432
Database initialized
# start it
> ./target/debug/zenith pg start pg1
# look up status and connection info
> ./target/debug/zenith pg list
NODE ADDRESS STATUS
pg1 127.0.0.1:55432 running
- Now it is possible to connect to postgres and run some queries:
> psql -p55432 -h 127.0.0.1 postgres
postgres=# CREATE TABLE t(key int primary key, value text);
CREATE TABLE
postgres=# insert into t values(1,1);
INSERT 0 1
postgres=# select * from t;
key | value
-----+-------
1 | 1
(1 row)
Running tests
git clone --recursive https://github.com/libzenith/zenith.git
make # builds also postgres and installs it to ./tmp_install
cargo test -- --test-threads=1
Source tree layout
/walkeeper:
WAL safekeeper. Written in Rust.
/pageserver:
Page Server. Written in Rust.
Depends on the modified 'postgres' binary for WAL redo.
/integration_tests:
Tests with different combinations of a Postgres compute node, WAL safekeeper and Page Server.
/mgmt-console:
Web UI to launch (modified) Postgres servers, using S3 as the backing store. Written in Python. This is somewhat outdated, as it doesn't use the WAL safekeeper or Page Servers.
/vendor/postgres:
PostgreSQL source tree, with the modifications needed for Zenith.
/vendor/postgres/src/bin/safekeeper:
Extension (safekeeper_proxy) that runs in the compute node, and connects to the WAL safekeepers and streams the WAL