Usage
Command line reference ............................................
.. code-block:: bash
chameleon command [ [ --config ] [ --source ] [ --schema ] [ --tables ] [--logid] [ --debug ] [ --rollbar-level ] ] [ --version ] [ --full ]
.. csv-table:: Options :header: "Option", "Description", "Default","Example"
--config, Specifies the configuration to use in ~.pg_chameleon/configuration/. The configuration name should be the file without the extension .yml , default,--config foo will use the file ~.pg_chameleon/configuration/foo.yml
--source, Specifies the source within a configuration file., N/A, --source bar
--schema, Specifies a schema configured within a source., N/A, --schema schema_foo
--tables, Specifies one or more tables configured in a schema. Multiple tables can be specified separated by comma. The table must have the schema., N/A, --tables schema_foo.table_bar
--logid, Specifies the log id entry for displaying the error details, N/A, --logid 30
--debug,When added to the command line the debug option disables any daemonisation and outputs all the logging to the console. The keybord interrupt signal is trapped correctly., N/A, --debug
--version,Displays the package version., N/A, --version
--rollbar-level, Sets the maximum level for the messages to be sent to rolllbar. Accepted values: "critical" "error" "warning" "info", info ,--rollbar-level error
--full,Runs a VACUUM FULL on the log tables when the run_maintenance is executed, N/A,--full
.. csv-table:: Command list reference :header: "Command", "Description", "Options"
``set_configuration_files``, Setup the example configuration files and directories in ``~/.pg_chameleon``
``show_config``, Displays the configuration for the configuration, ``--config``
``show_sources``, Displays the sourcches configured for the configuration, ``--config``
``show_status``,Displays an overview of the status of the sources configured within the configuration. Specifying the source gives more details about that source , ``--config`` ``--source``
``show_errors``,Displays the errors logged by the replay function. If a log id is specified then the log entry is displayed entirely, ``--config`` ``--logid``
``create_replica_schema``, Creates a new replication schema into the config's destination database, ``--config``
``drop_replica_schema``, Drops an existing replication schema from the config's destination database, ``--config``
``upgrade_replica_schema``,Upgrades the replica schema from a an older version,``--config``
``add_source``, Adds a new source to the replica catalogue, ``--config`` ``--source``
``drop_source``, Remove an existing source from the replica catalogue, ``--config`` ``--source``
``init_replica``, Initialise the replica for an existing source , ``--config`` ``--source``
``update_schema_mappings``,Update the schema mappings stored in the replica catalogue using the data from the configuration file. , ``--config`` ``--source``
``refresh_schema``, Synchronise all the tables for a given schema within an already initialised source. , ``--config`` ``--source`` ``--schema``
``sync_tables``, Synchronise one or more tables within an already initialised source. The switch ``--tables`` accepts the special name ``disabled`` to resync all the tables with replica disabled., ``--config`` ``--source`` ``--tables``
``start_replica``, Starts the replica process daemon, ``--config`` ``--source``
``stop_replica``, Stops the replica process daemon, ``--config`` ``--source``
``detach_replica``, Detaches a replica from the mysql master configuring the postgres schemas to work as a standalone system. Useful for migrations., ``--config`` ``--source``
``enable_replica``, Enables the replica for the given source changing the source status to stopped. It's useful if the replica crashes., ``--config`` ``--source``
``run_maintenance``, Runs a VACUUM on the log tables for the given source. If is specified then the maintenance runs a VACUUM FULL, ``--config`` ``--source`` ``--full``
``stop_all_replicas``, Stops all the running sources within the target postgresql database., ``--config``
Example ............................................
Create a virtualenv and activate it
.. code-block:: none
python3 -m venv venv
source venv/bin/activate
Install pg_chameleon
.. code-block:: none
pip install pip --upgrade
pip install pg_chameleon
Run the set_configuration_files command in order to create the configuration directory.
.. code-block:: none
chameleon set_configuration_files
cd in ~/.pg_chameleon/configuration and copy the file config-example.yml` to default.yml``.
In MySQL create a user for the replica.
.. code-block:: sql
CREATE USER usr_replica ;
SET PASSWORD FOR usr_replica=PASSWORD('replica');
GRANT ALL ON sakila.* TO 'usr_replica';
GRANT RELOAD ON *.* to 'usr_replica';
GRANT REPLICATION CLIENT ON *.* to 'usr_replica';
GRANT REPLICATION SLAVE ON *.* to 'usr_replica';
FLUSH PRIVILEGES;
Add the configuration for the replica to my.cnf. It requires a MySQL restart.
.. code-block:: none
binlog_format= ROW
binlog_row_image=FULL
log-bin = mysql-bin
server-id = 1
expire_logs_days = 10
In PostgreSQL create a user for the replica and a database owned by the user
.. code-block:: sql
CREATE USER usr_replica WITH PASSWORD 'replica';
CREATE DATABASE db_replica WITH OWNER usr_replica;
Check you can connect to both databases from the machine where pg_chameleon is installed.
For MySQL
.. code-block:: none
mysql -p -h derpy -u usr_replica sakila
Enter password:
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 116
Server version: 5.6.30-log Source distribution
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
For PostgreSQL
.. code-block:: none
psql -h derpy -U usr_replica db_replica
Password for user usr_replica:
psql (9.5.5)
Type "help" for help.
db_replica=>
Check the docs for the configuration file reference. It will help you to configure correctly the connections.
Initialise the replica
.. code-block:: none
chameleon create_replica_schema --debug
chameleon add_source --config default --debug
chameleon init_replica --config default --debug
Start the replica with
.. code-block:: none
chameleon start_replica --config default --source example
Check the source status
.. code-block:: none
chameleon show_status --source example
Check the error log
.. code-block:: none
chameleon show_errors
.. code-block:: none
chameleon start_replica --config default --source example
To stop the replica
.. code-block:: none
chameleon stop_replica --config default --source example
To detach the replica
.. code-block:: none
chameleon detach_replica --config default --source example