Monday 20 March 2017

pg_chameleon beta 1 out

After fixing few bugs I decided to release the first pg_chameleon beta.

The package details with the changelog are available here http://www.pgdba.co.uk/p/mysql-to-postgresql-replica.html

These are the notable changes.

  • Switch to psycopg2 2.7.x - Thanks to Daniele's work now the requirement installs without need for python or postgresql headers, making the install in virtualenv much simpler
  • Install system wide or in virtualenv follow the same rules. The configuration files and the package files are installed in the python's site-packages/pg_chameleon. 
  • Configuration directory created at first run. If not present the $HOME/.pg_chameleon/ directory is created when chameleon.py is executed the first time. The script creates  the directory and the required config dir with the config-example.yaml file. 
  • The write_batch function is now using the copy_expert in order to speedup the batch load. The fallback to inserts is still present.
 The release is already available on pypi https://pypi.python.org/pypi/pg_chameleon/

The documentation is available here http://pythonhosted.org/pg_chameleon/

Please report any issue on the project's github page https://github.com/the4thdoctor/pg_chameleon

However if you like to get in touch you can ping me on twitter @4thdoctor_scarf or if you prefer to chat, on irc there is a dedicated channel irc.freenode.net #pgchameleon (you can find me logged in at night).

Thursday 2 March 2017

pg_chameleon alpha4 available on pypi

Over the last week end I finally worked trough python's setuptools and relased the  alpha4 for pg_chameleon 1.0.
This is the final alpha version the version 1.0.

The system now can be installed in the virtualenv just typing
 pip install pg_chameleon

It's important pip is up to date so if there's any error upgrade pip with

pip install pip --upgrade

The first install creates in the user's home the directory .pg_chameleon with 4 subdirectories.

  • config is where the configuration files are stored. Use config-example.yaml as template for the other configuration files. If you have already a config file from a previous test you can copy there and the system should work. You will need to update the paths of logs and pid directories. The previous values with relative paths will no longer work. You can use  either use an absolute path or provide the home alias ~. Check the config-example.yaml for the latter configuration.
  • pid is where the replica pid is created. it can be changed in the configuration file.
  • logs is where the replication logs are created. it can be changed in the configuration file
  • sql stores the sql service files and upgrade files, you can ignore it

It's also possible to install pg_chameleon system wide (if you have root privileges). In that case the user's directory is not created. An example structure is put in /usr/local/etc/pg_chameleon.

You should copy the directory in the user's home dir (with the . prefix).
Using directly the general directory is not a good idea for security reasons.

The wrapper script which becomes chameleon.py.

Usage and examples in the documents.

pypi: https://pypi.python.org/pypi/pg_chameleon/1.0a4
github: https://github.com/the4thdoctor/pg_chameleon
documentation: http://pg-chameleon.readthedocs.io/en/v1.0-alpha.4/

Please test!

Thank you.