PGXL-docker with PostGis extension

Postgre-XL is a new MPP fork of PostgreSQL.

This version is a test of Postgre-XL with PostGis extension with docker, the default configuration file runs several data nodes, 1 gtm and 1 coordinator. The docker configuration is not fully functional and is unsecure (run with docker privilegied mode, no password for postgresql coordinator).

Tutorial

You need python and docker and two python package docker-py and fig.

$ pip install fig

1. Building

$ git clone https://github.com/wangxiaodong1021/pgxl-docker.git

Building the container:

$ fig build

This script generate ssh key in the directory pom/.ssh to allow container passwordless ssh connections.

$ fig run pgxl key

2. Starting containers

We use fig to facilitate container building and running. The fig scale command create several pgxl containers. Here 4 containers are started.

$ fig scale pgxl=4
Starting pgxldocker_pgxl_1...
Starting pgxldocker_pgxl_2...
Starting pgxldocker_pgxl_3...
Starting pgxldocker_pgxl_4...

You can check the containers status with fig ps:

$ fig ps

      Name                     Command             State     Ports
------------------------------------------------------------------------------
pgxldocker_pgxl_1   /app/entrypoint.sh supervisor   Up      5432/tcp
pgxldocker_pgxl_2   /app/entrypoint.sh supervisor   Up      5432/tcp
pgxldocker_pgxl_3   /app/entrypoint.sh supervisor   Up      5432/tcp
pgxldocker_pgxl_4   /app/entrypoint.sh supervisor   Up      5432/tcp

Postgres-XL configuration

The script run.py use docker-py API to inspect the started containers and generate a configuration file for Postgres-XL.

The —ip argument displays the running containers:

$ python run.py --ip

The —conf command generates the configuration file:

$ python run.py --conf pom/pgxc_ctl

3. Starting Postgres-XL

To start easily Postgres-XL we use the tool pgxc_ctl that automates the launching of the services.

First, we connect to the coordinator container (coordMasterServers) using the generated ssh key.

$ ssh -i pom/.ssh/id_rsa pom@172.17.0.2

We start the pgxc_ctl tool:

$ pgxc_ctl
Installing pgxc_ctl_bash script as /pom/pgxc_ctl/pgxc_ctl_bash.
Installing pgxc_ctl_bash script as /pom/pgxc_ctl/pgxc_ctl_bash.
Reading configuration using /pom/pgxc_ctl/pgxc_ctl_bash --home /pom/pgxc_ctl --configuration /pom/pgxc_ctl/pgxc_ctl.conf
Finished to read configuration.
   ******** PGXC_CTL START ***************

Current directory: /pom/pgxc_ctl
PGXC

Postgres-XL initializations:

PGXC init all

4. Extend PostGis

To enable PostGIS (includes raster), you just need to connect a coord after initialize the PGXL.

$  psql -h 172.17.0.4 -U pom postgres

CREATE EXTENSION postgis;

5. Test Spatial SQL

-- Create table with spatial column
CREATE TABLE mytable (
  id SERIAL PRIMARY KEY,
  geom GEOMETRY(Point, 26910),
  name VARCHAR(128)
);

-- Add a spatial index
CREATE INDEX mytable_gix
  ON mytable
  USING GIST (geom);

-- Add a point
INSERT INTO mytable (geom) VALUES (
  ST_GeomFromText('POINT(0 0)', 26910)
);

-- Query for nearby points
SELECT id, name
FROM mytable
WHERE ST_DWithin(
  geom,
  ST_GeomFromText('POINT(0 0)', 26910),
  1000
);

Authors

Matthieu Lagacherie , Yannick Drant and Xiaodong Wang

wangxiaodong1021 / pgxl-docker