Jdbc input plugin v5.0.2

  • Plugin version: v5.0.2
  • Released on: 2020-05-11
  • Changelog

For other versions, see the overview list.

To learn more about Logstash, see the Logstash Reference.

Getting Help

For questions about the plugin, open a topic in the Discuss forums. For bugs or feature requests, open an issue in Github. For the list of Elastic supported plugins, please consult the Elastic Support Matrix.

Description

This plugin was created as a way to ingest data in any database with a JDBC interface into Logstash. You can periodically schedule ingestion using a cron syntax (see schedule setting) or run the query one time to load data into Logstash. Each row in the resultset becomes a single event. Columns in the resultset are converted into fields in the event.

Drivers

This plugin does not come packaged with JDBC driver libraries. The desired jdbc driver library must be explicitly passed in to the plugin using the jdbc_driver_library configuration option.

See the jdbc_driver_library and jdbc_driver_class options for more info.

Scheduling

Input from this plugin can be scheduled to run periodically according to a specific schedule. This scheduling syntax is powered by rufus-scheduler. The syntax is cron-like with some extensions specific to Rufus (e.g. timezone support ).

Examples:

* 5 * 1-3 *

will execute every minute of 5am every day of January through March.

0 * * * *

will execute on the 0th minute of every hour every day.

0 6 * * * America/Chicago

will execute at 6:00am (UTC/GMT -5) every day.

Further documentation describing this syntax can be found here.

State

The plugin will persist the sql_last_value parameter in the form of a metadata file stored in the configured last_run_metadata_path. Upon query execution, this file will be updated with the current value of sql_last_value. Next time the pipeline starts up, this value will be updated by reading from the file. If clean_run is set to true, this value will be ignored and sql_last_value will be set to Jan 1, 1970, or 0 if use_column_value is true, as if no query has ever been executed.

Dealing With Large Result-sets

Many JDBC drivers use the fetch_size parameter to limit how many results are pre-fetched at a time from the cursor into the client’s cache before retrieving more results from the result-set. This is configured in this plugin using the jdbc_fetch_size configuration option. No fetch size is set by default in this plugin, so the specific driver’s default size will be used.

Usage:

Here is an example of setting up the plugin to fetch data from a MySQL database. First, we place the appropriate JDBC driver library in our current path (this can be placed anywhere on your filesystem). In this example, we connect to the mydb database using the user: mysql and wish to input all rows in the songs table that match a specific artist. The following examples demonstrates a possible Logstash configuration for this. The schedule option in this example will instruct the plugin to execute this input statement on the minute, every minute.

input {
  jdbc {
    jdbc_driver_library => "mysql-connector-java-5.1.36-bin.jar"
    jdbc_driver_class => "com.mysql.jdbc.Driver"
    jdbc_connection_string => "jdbc:mysql://localhost:3306/mydb"
    jdbc_user => "mysql"
    parameters => { "favorite_artist" => "Beethoven" }
    schedule => "* * * * *"
    statement => "SELECT * from songs where artist = :favorite_artist"
  }
}

Configuring SQL statement

A sql statement is required for this input. This can be passed-in via a statement option in the form of a string, or read from a file (statement_filepath). File option is typically used when the SQL statement is large or cumbersome to supply in the config. The file option only supports one SQL statement. The plugin will only accept one of the options. It cannot read a statement from a file as well as from the statement configuration parameter.

Configuring multiple SQL statements

Configuring multiple SQL statements is useful when there is a need to query and ingest data from different database tables or views. It is possible to define separate Logstash configuration files for each statement or to define multiple statements in a single configuration file. When using multiple statements in a single Logstash configuration file, each statement has to be defined as a separate jdbc input (including jdbc driver, connection string and other required parameters).

Please note that if any of the statements use the sql_last_value parameter (e.g. for ingesting only data changed since last run), each input should define its own last_run_metadata_path parameter. Failure to do so will result in undesired behaviour, as all inputs will store their state to the same (default) metadata file, effectively overwriting each other’s sql_last_value.

Predefined Parameters

Some parameters are built-in and can be used from within your queries. Here is the list:

sql_last_value

The value used to calculate which rows to query. Before any query is run, this is set to Thursday, 1 January 1970, or 0 if use_column_value is true and tracking_column is set. It is updated accordingly after subsequent queries are run.

Example:

input {
  jdbc {
    statement => "SELECT id, mycolumn1, mycolumn2 FROM my_table WHERE id > :sql_last_value"
    use_column_value => true
    tracking_column => "id"
    # ... other configuration bits
  }
}

Prepared Statements

Using server side prepared statements can speed up execution times as the server optimises the query plan and execution.

Not all JDBC accessible technologies will support prepared statements.

With the introduction of Prepared Statement support comes a different code execution path and some new settings. Most of the existing settings are still useful but there are several new settings for Prepared Statements to read up on. Use the boolean setting use_prepared_statements to enable this execution mode. Use the prepared_statement_name setting to specify a name for the Prepared Statement, this identifies the prepared statement locally and remotely and it should be unique in your config and on the database. Use the prepared_statement_bind_values array setting to specify the bind values, use the exact string :sql_last_value (multiple times if necessary) for the predefined parameter mentioned before. The statement (or statement_path) setting still holds the SQL statement but to use bind variables you must use the ? character as a placeholder in the exact order found in the prepared_statement_bind_values array.

Building count queries around a prepared statement is not supported at this time and because jdbc paging uses count queries under the hood, jdbc paging is not supported with prepared statements at this time either. Therefore, jdbc_paging_enabled, jdbc_page_size settings are ignored when using prepared statements.

Example:

input {
  jdbc {
    statement => "SELECT * FROM mgd.seq_sequence WHERE _sequence_key > ? AND _sequence_key < ? + ? ORDER BY _sequence_key ASC"
    prepared_statement_bind_values => [":sql_last_value", ":sql_last_value", 4]
    prepared_statement_name => "foobar"
    use_prepared_statements => true
    use_column_value => true
    tracking_column_type => "numeric"
    tracking_column => "_sequence_key"
    last_run_metadata_path => "/elastic/tmp/testing/confs/test-jdbc-int-sql_last_value.yml"
    # ... other configuration bits
  }
}

Jdbc Input Configuration Options

This plugin supports the following configuration options plus the Common Options described later.

Also see Common Options for a list of options supported by all input plugins.

 

clean_run

  • Value type is boolean
  • Default value is false

Whether the previous run state should be preserved

columns_charset

  • Value type is hash
  • Default value is {}

The character encoding for specific columns. This option will override the :charset option for the specified columns.

Example:

input {
  jdbc {
    ...
    columns_charset => { "column0" => "ISO-8859-1" }
    ...
  }
}

this will only convert column0 that has ISO-8859-1 as an original encoding.

connection_retry_attempts

  • Value type is number
  • Default value is 1

Maximum number of times to try connecting to database

connection_retry_attempts_wait_time

  • Value type is number
  • Default value is 0.5

Number of seconds to sleep between connection attempts

jdbc_connection_string

  • This is a required setting.
  • Value type is string
  • There is no default value for this setting.

JDBC connection string

jdbc_default_timezone

  • Value type is string
  • There is no default value for this setting.

Timezone conversion. Logstash (and Elasticsearch) expects that timestamps are expressed in UTC terms. If your database has recorded timestamps that are relative to another timezone, the database timezone if you will, then set this setting to be the timezone that the database is using. However, as SQL does not allow for timezone data in timestamp fields we can’t figure this out on a record by record basis. This plugin will automatically convert your SQL timestamp fields to Logstash timestamps, in relative UTC time in ISO8601 format.

Using this setting will manually assign a specified timezone offset, instead of using the timezone setting of the local machine. You must use a canonical timezone, America/Denver, for example.

plugin_timezone

  • Value can be any of: utc, local
  • Default value is "utc"

If you want this plugin to offset timestamps to a timezone other than UTC, you can set this setting to local and the plugin will use the OS timezone for offset adjustments.

Note: when specifying plugin_timezone and/or jdbc_default_timezone, offset adjustments are made in two places, if sql_last_value is a timestamp and it is used as a parameter in the statement then offset adjustment is done from the plugin timezone into the data timezone and while records are processed, timestamps are offset adjusted from the database timezone to the plugin timezone. If your database timezone is UTC then you do not need to set either of these settings.

jdbc_driver_class

  • This is a required setting.
  • Value type is string
  • There is no default value for this setting.

JDBC driver class to load, for example, "org.apache.derby.jdbc.ClientDriver"

Per https://github.com/logstash-plugins/logstash-input-jdbc/issues/43, prepending Java:: to the driver class may be required if it appears that the driver is not being loaded correctly despite relevant jar(s) being provided by either via the jdbc_driver_library setting or being placed in the Logstash Java classpath. This is known to be the case for the Oracle JDBC driver (ojdbc6.jar), where the correct jdbc_driver_class is "Java::oracle.jdbc.driver.OracleDriver", and may also be the case for other JDBC drivers.

jdbc_driver_library

  • Value type is string
  • There is no default value for this setting.

JDBC driver library path to third party driver library. In case of multiple libraries being required you can pass them separated by a comma.

If not provided, Plugin will look for the driver class in the Logstash Java classpath. Additionally, if the library does not appear to be being loaded correctly via this setting, placing the relevant jar(s) in the Logstash Java classpath rather than via this setting may help. Please also make sure the path is readable by the Logstash process (e.g. logstash user when running as a service).

jdbc_fetch_size

  • Value type is number
  • There is no default value for this setting.

JDBC fetch size. if not provided, respective driver’s default will be used

jdbc_page_size

  • Value type is number
  • Default value is 100000

JDBC page size

jdbc_paging_enabled

  • Value type is boolean
  • Default value is false

JDBC enable paging

This will cause a sql statement to be broken up into multiple queries. Each query will use limits and offsets to collectively retrieve the full result-set. The limit size is set with jdbc_page_size.

Be aware that ordering is not guaranteed between queries.

jdbc_password

  • Value type is password
  • There is no default value for this setting.

JDBC password

jdbc_password_filepath

  • Value type is path
  • There is no default value for this setting.

JDBC password filename

jdbc_pool_timeout

  • Value type is number
  • Default value is 5

Connection pool configuration. The amount of seconds to wait to acquire a connection before raising a PoolTimeoutError (default 5)

jdbc_user

  • This is a required setting.
  • Value type is string
  • There is no default value for this setting.

JDBC user

jdbc_validate_connection

  • Value type is boolean
  • Default value is false

Connection pool configuration. Validate connection before use.

jdbc_validation_timeout

  • Value type is number
  • Default value is 3600

Connection pool configuration. How often to validate a connection (in seconds)

last_run_metadata_path

  • Value type is string
  • Default value is "$HOME/.logstash_jdbc_last_run"

Path to file with last run time

lowercase_column_names

  • Value type is boolean
  • Default value is true

Whether to force the lowercasing of identifier fields

parameters

  • Value type is hash
  • Default value is {}

Hash of query parameter, for example { "target_id" => "321" }

prepared_statement_bind_values

  • Value type is array
  • Default value is []

Array of bind values for the prepared statement. :sql_last_value is a reserved predefined string

prepared_statement_name

  • Value type is string
  • Default value is ""

Name given to the prepared statement. It must be unique in your config and in the database

record_last_run

  • Value type is boolean
  • Default value is true

Whether to save state or not in last_run_metadata_path

schedule

  • Value type is string
  • There is no default value for this setting.

Schedule of when to periodically run statement, in Cron format for example: "* * * * *" (execute query every minute, on the minute)

There is no schedule by default. If no schedule is given, then the statement is run exactly once.

sequel_opts

  • Value type is hash
  • Default value is {}

General/Vendor-specific Sequel configuration options.

An example of an optional connection pool configuration max_connections - The maximum number of connections the connection pool

examples of vendor-specific options can be found in this documentation page: https://github.com/jeremyevans/sequel/blob/master/doc/opening_databases.rdoc

sql_log_level

  • Value can be any of: fatal, error, warn, info, debug
  • Default value is "info"

Log level at which to log SQL queries, the accepted values are the common ones fatal, error, warn, info and debug. The default value is info.

statement

  • Value type is string
  • There is no default value for this setting.

If undefined, Logstash will complain, even if codec is unused. Statement to execute

To use parameters, use named parameter syntax. For example:

"SELECT * FROM MYTABLE WHERE id = :target_id"

here, ":target_id" is a named parameter. You can configure named parameters with the parameters setting.

statement_filepath

  • Value type is path
  • There is no default value for this setting.

Path of file containing statement to execute

tracking_column

  • Value type is string
  • There is no default value for this setting.

The column whose value is to be tracked if use_column_value is set to true

tracking_column_type

  • Value can be any of: numeric, timestamp
  • Default value is "numeric"

Type of tracking column. Currently only "numeric" and "timestamp"

use_column_value

  • Value type is boolean
  • Default value is false

When set to true, uses the defined tracking_column value as the :sql_last_value. When set to false, :sql_last_value reflects the last time the query was executed.

use_prepared_statements

  • Value type is boolean
  • Default value is false

When set to true, enables prepare statement usage

Common Options

The following configuration options are supported by all input plugins:

Setting Input type Required

add_field

hash

No

codec

codec

No

enable_metric

boolean

No

id

string

No

tags

array

No

type

string

No

Details

 

add_field

  • Value type is hash
  • Default value is {}

Add a field to an event

codec

  • Value type is codec
  • Default value is "plain"

The codec used for input data. Input codecs are a convenient method for decoding your data before it enters the input, without needing a separate filter in your Logstash pipeline.

enable_metric

  • Value type is boolean
  • Default value is true

Disable or enable metric logging for this specific plugin instance by default we record all the metrics we can, but you can disable metrics collection for a specific plugin.

id

  • Value type is string
  • There is no default value for this setting.

Add a unique ID to the plugin configuration. If no ID is specified, Logstash will generate one. It is strongly recommended to set this ID in your configuration. This is particularly useful when you have two or more plugins of the same type, for example, if you have 2 jdbc inputs. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

input {
  jdbc {
    id => "my_plugin_id"
  }
}

tags

  • Value type is array
  • There is no default value for this setting.

Add any number of arbitrary tags to your event.

This can help with processing later.

type

  • Value type is string
  • There is no default value for this setting.

Add a type field to all events handled by this input.

Types are used mainly for filter activation.

The type is stored as part of the event itself, so you can also use the type to search for it in Kibana.

If you try to set a type on an event that already has one (for example when you send an event from a shipper to an indexer) then a new input will not override the existing type. A type set at the shipper stays with that event for its life even when sent to another Logstash server.