Singer tap that extracts data from a MySQL database and produces JSON-formatted data following the Singer spec.
This is a PipelineWise compatible tap connector.
The recommended method of running this tap is to use it from PipelineWise. When running it from PipelineWise you don't need to configure this tap with JSON files and most of things are automated. Please check the related documentation at Tap MySQL
If you want to run this Singer Tap independently please read further.
This section dives into basic usage of tap-mysql by walking through extracting
data from a table. It assumes that you can connect to and read from a MySQL
database.
First, make sure Python 3 is installed on your system or follow these installation instructions for Mac or Ubuntu.
It's recommended to use a virtualenv:
python3 -m venv venv
pip install pipelinewise-tap-mysqlor
python3 -m venv venv
. venv/bin/activate
pip install --upgrade pip
pip install .There's some important business data siloed in this MySQL database -- we need to extract it. Here's the table we'd like to sync:
mysql> select * from example_db.animals;
+----|----------|----------------------+
| id | name | likes_getting_petted |
+----|----------|----------------------+
| 1 | aardvark | 0 |
| 2 | bear | 0 |
| 3 | cow | 1 |
+----|----------|----------------------+
3 rows in set (0.00 sec)
Create a config file containing the database connection credentials, see sample.
List of config parameters:
| Parameter | type | required | default | description |
|---|---|---|---|---|
| host | string | yes | - | mysql/mariadb host |
| port | int | yes | - | mysql/mariadb port |
| user | string | yes | - | db username |
| password | string | yes | - | db password |
| cursorclass | string | No | pymysql.cursors.SSCursor |
set cursorclass used by PyMYSQL |
| database | string | No | - | Database to use, None to not use a particular one. Used by PyMYSQL |
| server_id | int | False | Randomly generated int | Used as the slave id when this tap is connecting to the server |
| filter_db | string | False | - | Comma separated list of schemas to extract tables only from particular schemas and to improve data extraction performance |
| use_gtid | bool | False | False |
Flag to enable log based replication using GTID |
| engine | string ('mysql' or 'mariadb') | False | 'mysql' | Indicate which flavor the server is, used for LOG_BASED with GTID |
| ssl | string ("true") | No | False | Enable SSL connection |
| ssl_ca | string | No | - | for self-signed SSL |
| ssl_cert | string | No | - | for self-signed SSL |
| ssl_key | string | No | - | for self-signed SSL |
| internal_hostname | string | No | - | Override match hostname for google cloud |
| session_sqls | List of strings | No | ['SET @@session.time_zone="+0:00"', 'SET @@session.wait_timeout=28800', 'SET @@session.net_read_timeout=3600', 'SET @@session.innodb_lock_wait_timeout=3600'] |
Set session variables dynamically. |
The tap can be invoked in discovery mode to find the available tables and columns in the database:
$ tap-mysql --config config.json --discover
A discovered catalog is output, with a JSON-schema description of each table. A source table directly corresponds to a Singer stream.
{
"streams": [
{
"tap_stream_id": "example_db-animals",
"table_name": "animals",
"schema": {
"type": "object",
"properties": {
"name": {
"inclusion": "available",
"type": [
"null",
"string"
],
"maxLength": 255
},
"id": {
"inclusion": "automatic",
"minimum": -2147483648,
"maximum": 2147483647,
"type": [
"null",
"integer"
]
},
"likes_getting_petted": {
"inclusion": "available",
"type": [
"null",
"boolean"
]
}
}
},
"metadata": [
{
"breadcrumb": [],
"metadata": {
"row-count": 3,
"table-key-properties": [
"id"
],
"database-name": "example_db",
"selected-by-default": false,
"is-view": false,
}
},
{
"breadcrumb": [
"properties",
"id"
],
"metadata": {
"sql-datatype": "int(11)",
"selected-by-default": true
}
},
{
"breadcrumb": [
"properties",
"name"
],
"metadata": {
"sql-datatype": "varchar(255)",
"selected-by-default": true
}
},
{
"breadcrumb": [
"properties",
"likes_getting_petted"
],
"metadata": {
"sql-datatype": "tinyint(1)",
"selected-by-default": true
}
}
],
"stream": "animals"
}
]
}
In sync mode, tap-mysql consumes the catalog and looks for tables and fields
have been marked as selected in their associated metadata entries.
Redirect output from the tap's discovery mode to a file so that it can be modified:
$ tap-mysql -c config.json --discover > properties.jsonThen edit properties.json to make selections. In this example we want the
animals table. The stream's metadata entry (associated with "breadcrumb": [])
gets a top-level selected flag, as does its columns' metadata entries. Additionally,
we will mark the animals table to replicate using a FULL_TABLE strategy. For more,
information, see Replication methods and state file.
[
{
"breadcrumb": [],
"metadata": {
"row-count": 3,
"table-key-properties": [
"id"
],
"database-name": "example_db",
"selected-by-default": false,
"is-view": false,
"selected": true,
"replication-method": "FULL_TABLE"
}
},
{
"breadcrumb": [
"properties",
"id"
],
"metadata": {
"sql-datatype": "int(11)",
"selected-by-default": true,
"selected": true
}
},
{
"breadcrumb": [
"properties",
"name"
],
"metadata": {
"sql-datatype": "varchar(255)",
"selected-by-default": true,
"selected": true
}
},
{
"breadcrumb": [
"properties",
"likes_getting_petted"
],
"metadata": {
"sql-datatype": "tinyint(1)",
"selected-by-default": true,
"selected": true
}
}
]With a properties catalog that describes field and table selections, the tap can be invoked in sync mode:
$ tap-mysql -c config.json --properties properties.jsonMessages are written to standard output following the Singer specification. The resultant stream of JSON data can be consumed by a Singer target.
{"value": {"currently_syncing": "example_db-animals"}, "type": "STATE"}
{"key_properties": ["id"], "stream": "animals", "schema": {"properties": {"name": {"inclusion": "available", "maxLength": 255, "type": ["null", "string"]}, "likes_getting_petted": {"inclusion": "available", "type": ["null", "boolean"]}, "id": {"inclusion": "automatic", "minimum": -2147483648, "type": ["null", "integer"], "maximum": 2147483647}}, "type": "object"}, "type": "SCHEMA"}
{"stream": "animals", "version": 1509133344771, "type": "ACTIVATE_VERSION"}
{"record": {"name": "aardvark", "likes_getting_petted": false, "id": 1}, "stream": "animals", "version": 1509133344771, "type": "RECORD"}
{"record": {"name": "bear", "likes_getting_petted": false, "id": 2}, "stream": "animals", "version": 1509133344771, "type": "RECORD"}
{"record": {"name": "cow", "likes_getting_petted": true, "id": 3}, "stream": "animals", "version": 1509133344771, "type": "RECORD"}
{"stream": "animals", "version": 1509133344771, "type": "ACTIVATE_VERSION"}
{"value": {"currently_syncing": "example_db-animals", "bookmarks": {"example_db-animals": {"initial_full_table_complete": true}}}, "type": "STATE"}
{"value": {"currently_syncing": null, "bookmarks": {"example_db-animals": {"initial_full_table_complete": true}}}, "type": "STATE"}In the above example, we invoked tap-mysql without providing a state file and without specifying a replication
method. The ways to replicate a given table are FULL_TABLE, LOG_BASED and INCREMENTAL.
LOG_BASED replication makes use of the server's binary logs (binlogs), this method can work with primary servers, the tap acts as a replica and requests the primary to stream log events,the tap then consumes events pertaining to row changes (inserts, updates, deletes), binlog file rotate and gtid events.
Log_based method always requires an initial sync to get a snapshot of the table and current binlog coordinates/gtid position.
The tap support two ways of consuming log events: using binlog coordinates or GTID, the default behavior is using
binlog coordinates, when turning the use_gtid flag, you have to specify the engine flavor (mariadb/mysql) due to
how different are the GTID implementations in these two engines.
When enabling the use_gtid flag and the engine is MariaDB, the tap will dynamically infer the GTID pos from
existing binlog coordinate in the state, if the engine is mysql, it will fail.
{
"bookmarks": {
"example_db-table1": {"log_file": "mysql-binlog.0003", "log_pos": 3244},
"example_db-table2": {"log_file": "mysql-binlog.0001", "log_pos": 42},
"example_db-table3": {"log_file": "mysql-binlog.0003", "log_pos": 100}
}
}{
"bookmarks": {
"example_db-table1": {"log_file": "mysql-binlog.0003", "log_pos": 3244, "gtid": "0:364864374:599"},
"example_db-table2": {"log_file": "mysql-binlog.0001", "log_pos": 42, "gtid": "0:364864374:375"},
"example_db-table3": {"log_file": "mysql-binlog.0003", "log_pos": 100, "gtid": "0:364864374:399"}
}
}Full-table replication extracts all data from the source table each time the tap is invoked.
Incremental replication works in conjunction with a state file to only extract new records each time the tap is invoked. This requires a replication key to be specified in the table's metadata as well.
Let's sync the animals table again, but this time using incremental
replication. The replication method and replication key are set in the
table's metadata entry in properties file:
{
"streams": [
{
"tap_stream_id": "example_db-animals",
"table_name": "animals",
"schema": { ... },
"metadata": [
{
"breadcrumb": [],
"metadata": {
"row-count": 3,
"table-key-properties": [
"id"
],
"database-name": "example_db",
"selected-by-default": false,
"is-view": false,
"replication-method": "INCREMENTAL",
"replication-key": "id"
}
},
...
],
"stream": "animals"
}
]
}We have no meaningful state so far, so just invoke the tap in sync mode again without a state file:
$ tap-mysql -c config.json --properties properties.jsonThe output messages look very similar to when the table was replicated using the
default FULL_TABLE replication method. One important difference is that the
STATE messages now contain a replication_key_value -- a bookmark or
high-water mark -- for data that was extracted:
{"type": "STATE", "value": {"currently_syncing": "example_db-animals"}}
{"stream": "animals", "type": "SCHEMA", "schema": {"type": "object", "properties": {"id": {"type": ["null", "integer"], "minimum": -2147483648, "maximum": 2147483647, "inclusion": "automatic"}, "name": {"type": ["null", "string"], "inclusion": "available", "maxLength": 255}, "likes_getting_petted": {"type": ["null", "boolean"], "inclusion": "available"}}}, "key_properties": ["id"]}
{"stream": "animals", "type": "ACTIVATE_VERSION", "version": 1509135204169}
{"stream": "animals", "type": "RECORD", "version": 1509135204169, "record": {"id": 1, "name": "aardvark", "likes_getting_petted": false}}
{"stream": "animals", "type": "RECORD", "version": 1509135204169, "record": {"id": 2, "name": "bear", "likes_getting_petted": false}}
{"stream": "animals", "type": "RECORD", "version": 1509135204169, "record": {"id": 3, "name": "cow", "likes_getting_petted": true}}
{"type": "STATE", "value": {"bookmarks": {"example_db-animals": {"version": 1509135204169, "replication_key_value": 3, "replication_key": "id"}}, "currently_syncing": "example_db-animals"}}
{"type": "STATE", "value": {"bookmarks": {"example_db-animals": {"version": 1509135204169, "replication_key_value": 3, "replication_key": "id"}}, "currently_syncing": null}}Note that the final STATE message has a replication_key_value of 3,
reflecting that the extraction ended on a record that had an id of 3.
Subsequent invocations of the tap will pick up from this bookmark.
Normally, the target will echo the last STATE after it's finished processing
data. For this example, let's manually write a state.json file using the
STATE message:
{
"bookmarks": {
"example_db-animals": {
"version": 1509135204169,
"replication_key_value": 3,
"replication_key": "id"
}
},
"currently_syncing": null
}Let's add some more animals to our farm:
mysql> insert into animals (name, likes_getting_petted) values ('dog', true), ('elephant', true), ('frog', false);
$ tap-mysql -c config.json --properties properties.json --state state.jsonThis invocation extracts any data since (and including) the
replication_key_value:
{"type": "STATE", "value": {"bookmarks": {"example_db-animals": {"replication_key": "id", "version": 1509135204169, "replication_key_value": 3}}, "currently_syncing": "example_db-animals"}}
{"key_properties": ["id"], "schema": {"properties": {"name": {"maxLength": 255, "inclusion": "available", "type": ["null", "string"]}, "id": {"maximum": 2147483647, "minimum": -2147483648, "inclusion": "automatic", "type": ["null", "integer"]}, "likes_getting_petted": {"inclusion": "available", "type": ["null", "boolean"]}}, "type": "object"}, "type": "SCHEMA", "stream": "animals"}
{"type": "ACTIVATE_VERSION", "version": 1509135204169, "stream": "animals"}
{"record": {"name": "cow", "id": 3, "likes_getting_petted": true}, "type": "RECORD", "version": 1509135204169, "stream": "animals"}
{"record": {"name": "dog", "id": 4, "likes_getting_petted": true}, "type": "RECORD", "version": 1509135204169, "stream": "animals"}
{"record": {"name": "elephant", "id": 5, "likes_getting_petted": true}, "type": "RECORD", "version": 1509135204169, "stream": "animals"}
{"record": {"name": "frog", "id": 6, "likes_getting_petted": false}, "type": "RECORD", "version": 1509135204169, "stream": "animals"}
{"type": "STATE", "value": {"bookmarks": {"example_db-animals": {"replication_key": "id", "version": 1509135204169, "replication_key_value": 6}}, "currently_syncing": "example_db-animals"}}
{"type": "STATE", "value": {"bookmarks": {"example_db-animals": {"replication_key": "id", "version": 1509135204169, "replication_key_value": 6}}, "currently_syncing": null}}- You'll need to have a running MySQL or MariaDB server to run the tests. Run the following SQL commands as a privileged user to create the required objects:
CREATE USER <mysql-user> IDENTIFIED BY '<mysql-password>';
CREATE DATABASE tap_mysql_test;
GRANT ALL PRIVILEGES ON tap_mysql_test.* TO <mysql-user>;
Note: The user and password can be anything but the database name needs to be tap_mysql_test.
- Define the environment variables that are required to run the tests:
export TAP_MYSQL_HOST=<mysql-host>
export TAP_MYSQL_PORT=<mysql-port>
export TAP_MYSQL_USER=<mysql-user>
export TAP_MYSQL_PASSWORD=<mysql-password>
- Install python test dependencies in a virtual env
python3 -m venv venv
. venv/bin/activate
pip install --upgrade pip
pip install .[test]- To run tests:
nosetests -c .noserc tests- Install python dependencies and run python linter
python3 -m venv venv
. venv/bin/activate
pip install --upgrade pip
pip install .[test]
pylint --rcfile .pylintrc tap_mysql
Based on Stitch documentation