:plugin: jdbc_streaming
:type: filter

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:version: %VERSION%
:release_date: %RELEASE_DATE%
:changelog_url: %CHANGELOG_URL%
:include_path: ../../../../logstash/docs/include
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END - GENERATED VARIABLES, DO NOT EDIT!
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[id="plugins-{type}s-{plugin}"]

=== Jdbc_streaming filter plugin

include::{include_path}/plugin_header.asciidoc[]

==== Description

This filter executes a SQL query and store the result set in the field
specified as `target`.
It will cache the results locally in an LRU cache with expiry.

For example, you can load a row based on an id in the event.

[source,ruby]
-----
filter {
  jdbc_streaming {
    jdbc_driver_library => "/path/to/mysql-connector-java-5.1.34-bin.jar"
    jdbc_driver_class => "com.mysql.jdbc.Driver"
    jdbc_connection_string => "jdbc:mysql://localhost:3306/mydatabase"
    jdbc_user => "me"
    jdbc_password => "secret"
    statement => "select * from WORLD.COUNTRY WHERE Code = :code"
    parameters => { "code" => "country_code"}
    target => "country_details"
  }
}
-----

[id="plugins-{type}s-{plugin}-prepared_statements"]
==== Prepared Statements

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

NOTE: 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. Typically, these values are indirectly extracted from your event, i.e. the string in the array refers to a field name in your event. You can also use constant values like numbers or strings but ensure that any string constants (e.g. a locale constant of "en" or "de") is not also an event field name. It is a good idea to use the bracketed field reference syntax for fields and normal strings for constants, e.g. `prepared_statement_bind_values => ["[src_ip]", "tokyo"],`.

There are 3 possible parameter schemes. Interpolated, field references and constants. Use interpolation when you are prefixing, suffixing or concatenating field values to create a value that exists in your database, e.g. "%{username}@%{domain}" -> "alice@example.org", "%{distance}km" -> "42km". Use field references for exact field values e.g. "[srcip]" -> "192.168.1.2". Use constants when a database column holds values that slice or categorise a number of similar records e.g. language translations.

A boolean setting `prepared_statement_warn_on_constant_usage`, defaulting to true, controls whether you will see a WARN message logged that warns when constants could be missing the bracketed field reference syntax. If you have set your field references and constants correctly you should set `prepared_statement_warn_on_constant_usage` to false. This setting and code checks should be deprecated in a future major Logstash release.

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.
Some technologies may require connection string properties to be set, see MySQL example below.

Example:
[source,ruby]
-----
filter {
  jdbc_streaming {
    jdbc_driver_library => "/path/to/mysql-connector-java-5.1.34-bin.jar"
    jdbc_driver_class => "com.mysql.jdbc.Driver"
    jdbc_connection_string => "jdbc:mysql://localhost:3306/mydatabase?cachePrepStmts=true&prepStmtCacheSize=250&prepStmtCacheSqlLimit=2048&useServerPrepStmts=true"
    jdbc_user => "me"
    jdbc_password => "secret"
    statement => "select * from WORLD.COUNTRY WHERE Code = ?"
    use_prepared_statements => true
    prepared_statement_name => "lookup_country_info"
    prepared_statement_bind_values => ["[country_code]"]
    target => "country_details"
  }
}
-----

[id="plugins-{type}s-{plugin}-options"]
==== Jdbc_streaming Filter Configuration Options

This plugin supports the following configuration options plus the <<plugins-{type}s-{plugin}-common-options>> described later.

[cols="<,<,<",options="header",]
|=======================================================================
|Setting |Input type|Required
| <<plugins-{type}s-{plugin}-cache_expiration>> |<<number,number>>|No
| <<plugins-{type}s-{plugin}-cache_size>> |<<number,number>>|No
| <<plugins-{type}s-{plugin}-default_hash>> |<<hash,hash>>|No
| <<plugins-{type}s-{plugin}-jdbc_connection_string>> |<<string,string>>|Yes
| <<plugins-{type}s-{plugin}-jdbc_driver_class>> |<<string,string>>|Yes
| <<plugins-{type}s-{plugin}-jdbc_driver_library>> |a valid filesystem path|No
| <<plugins-{type}s-{plugin}-jdbc_password>> |<<password,password>>|No
| <<plugins-{type}s-{plugin}-jdbc_user>> |<<string,string>>|No
| <<plugins-{type}s-{plugin}-jdbc_validate_connection>> |<<boolean,boolean>>|No
| <<plugins-{type}s-{plugin}-jdbc_validation_timeout>> |<<number,number>>|No
| <<plugins-{type}s-{plugin}-parameters>> |<<hash,hash>>|No
| <<plugins-{type}s-{plugin}-prepared_statement_bind_values>> |<<array,array>>|No
| <<plugins-{type}s-{plugin}-prepared_statement_name>> |<<string,string>>|No
| <<plugins-{type}s-{plugin}-prepared_statement_warn_on_constant_usage>> |<<boolean,boolean>>|No
| <<plugins-{type}s-{plugin}-sequel_opts>> |<<hash,hash>>|No
| <<plugins-{type}s-{plugin}-statement>> |<<string,string>>|Yes
| <<plugins-{type}s-{plugin}-tag_on_default_use>> |<<array,array>>|No
| <<plugins-{type}s-{plugin}-tag_on_failure>> |<<array,array>>|No
| <<plugins-{type}s-{plugin}-target>> |<<string,string>>|Yes
| <<plugins-{type}s-{plugin}-use_cache>> |<<boolean,boolean>>|No
| <<plugins-{type}s-{plugin}-use_prepared_statements>> |<<boolean,boolean>>|No
|=======================================================================

Also see <<plugins-{type}s-{plugin}-common-options>> for a list of options supported by all
filter plugins.

&nbsp;

[id="plugins-{type}s-{plugin}-cache_expiration"]
===== `cache_expiration`

  * Value type is <<number,number>>
  * Default value is `5.0`

The minimum number of seconds any entry should remain in the cache. Defaults to 5 seconds.

A numeric value. You can use decimals for example: `cache_expiration => 0.25`.
If there are transient jdbc errors, the cache will store empty results for a
given parameter set and bypass the jbdc lookup. This will merge the default_hash
into the event until the cache entry expires. Then the jdbc lookup will be tried
again for the same parameters. Conversely, while the cache contains valid results,
any external problem that would cause jdbc errors will not be noticed for the
cache_expiration period.

[id="plugins-{type}s-{plugin}-cache_size"]
===== `cache_size`

  * Value type is <<number,number>>
  * Default value is `500`

The maximum number of cache entries that will be stored. Defaults to 500 entries.
The least recently used entry will be evicted.

[id="plugins-{type}s-{plugin}-default_hash"]
===== `default_hash`

  * Value type is <<hash,hash>>
  * Default value is `{}`

Define a default object to use when lookup fails to return a matching row.
Ensure that the key names of this object match the columns from the statement.

[id="plugins-{type}s-{plugin}-jdbc_connection_string"]
===== `jdbc_connection_string`

  * This is a required setting.
  * Value type is <<string,string>>
  * There is no default value for this setting.

JDBC connection string

[id="plugins-{type}s-{plugin}-jdbc_driver_class"]
===== `jdbc_driver_class`

  * This is a required setting.
  * Value type is <<string,string>>
  * There is no default value for this setting.

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

[id="plugins-{type}s-{plugin}-jdbc_driver_library"]
===== `jdbc_driver_library`

  * Value type is <<path,path>>
  * There is no default value for this setting.

JDBC driver library path to third party driver library.

[id="plugins-{type}s-{plugin}-jdbc_password"]
===== `jdbc_password`

  * Value type is <<password,password>>
  * There is no default value for this setting.

JDBC password

[id="plugins-{type}s-{plugin}-jdbc_user"]
===== `jdbc_user`

  * Value type is <<string,string>>
  * There is no default value for this setting.

JDBC user

[id="plugins-{type}s-{plugin}-jdbc_validate_connection"]
===== `jdbc_validate_connection`

  * Value type is <<boolean,boolean>>
  * Default value is `false`

Connection pool configuration.
Validate connection before use.

[id="plugins-{type}s-{plugin}-jdbc_validation_timeout"]
===== `jdbc_validation_timeout`

  * Value type is <<number,number>>
  * Default value is `3600`

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

[id="plugins-{type}s-{plugin}-parameters"]
===== `parameters`

  * Value type is <<hash,hash>>
  * Default value is `{}`

Hash of query parameter, for example `{ "id" => "id_field" }`.

[id="plugins-{type}s-{plugin}-prepared_statement_bind_values"]
===== `prepared_statement_bind_values`

  * Value type is <<array,array>>
  * Default value is `[]`

Array of bind values for the prepared statement. Use field references and constants. See the section on <<plugins-{type}s-{plugin}-prepared_statements,prepared_statements>> for more info.

[id="plugins-{type}s-{plugin}-prepared_statement_name"]
===== `prepared_statement_name`

  * Value type is <<string,string>>
  * Default value is `""`

Name given to the prepared statement. It must be unique in your config and in the database.
You need to supply this if `use_prepared_statements` is true.

[id="plugins-{type}s-{plugin}-prepared_statement_warn_on_constant_usage"]
===== `prepared_statement_warn_on_constant_usage`

  * Value type is <<boolean,boolean>>
  * Default value is `true`

A flag that controls whether a warning is logged if, in `prepared_statement_bind_values`,
a String constant is detected that might be intended as a field reference.

[id="plugins-{type}s-{plugin}-sequel_opts"]
===== `sequel_opts`

  * Value type is <<hash,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

[id="plugins-{type}s-{plugin}-statement"]
===== `statement`

  * This is a required setting.
  * Value type is <<string,string>>
  * There is no default value for this setting.

Statement to execute.
To use parameters, use named parameter syntax, for example "SELECT * FROM MYTABLE WHERE ID = :id".

[id="plugins-{type}s-{plugin}-tag_on_default_use"]
===== `tag_on_default_use`

  * Value type is <<array,array>>
  * Default value is `["_jdbcstreamingdefaultsused"]`

Append values to the `tags` field if no record was found and default values were used.

[id="plugins-{type}s-{plugin}-tag_on_failure"]
===== `tag_on_failure`

  * Value type is <<array,array>>
  * Default value is `["_jdbcstreamingfailure"]`

Append values to the `tags` field if sql error occurred.

[id="plugins-{type}s-{plugin}-target"]
===== `target`

  * This is a required setting.
  * Value type is <<string,string>>
  * There is no default value for this setting.

Define the target field to store the extracted result(s).
Field is overwritten if exists.

[id="plugins-{type}s-{plugin}-use_cache"]
===== `use_cache`

  * Value type is <<boolean,boolean>>
  * Default value is `true`

Enable or disable caching, boolean true or false. Defaults to true.

[id="plugins-{type}s-{plugin}-use_prepared_statements"]
===== `use_prepared_statements`

  * Value type is <<boolean,boolean>>
  * Default value is `false`

When set to `true`, enables prepare statement usage

[id="plugins-{type}s-{plugin}-common-options"]
include::{include_path}/{type}.asciidoc[]
