Address issue 44.

Fix toString method of LogStash::Timestamp

.gitignore

@@ -0,0 +1,5 @@
+*.gem
+Gemfile.lock
+Gemfile.bak
+.bundle
+.vagrant

.travis.yml

@@ -0,0 +1,8 @@
+language: ruby
+cache: bundler
+rvm:
+  - jruby
+before_script:
+  - wget http://search.maven.org/remotecontent?filepath=org/apache/derby/derby/10.12.1.1/derby-10.12.1.1.jar -O /tmp/derby.jar
+  - export JDBC_DERBY_JAR=/tmp/derby.jar
+script: bundle exec rspec

CHANGELOG.md

@@ -0,0 +1,28 @@
+# Change Log
+All notable changes to this project will be documented in this file, from 0.2.0.
+
+## [0.2.7] - 2016-05-29
+  - Backport retry exception logic from v5 branch
+  - Backport improved timestamp compatibility from v5 branch
+
+## [0.2.6] - 2016-05-02
+  - Fix for exception infinite loop
+
+## [0.2.5] - 2016-04-11
+### Added
+  - Basic tests running against DerbyDB
+  - Fix for converting Logstash::Timestamp to iso8601 from @hordijk
+
+## [0.2.4] - 2016-04-07
+  - Documentation fixes from @hordijk
+
+## [0.2.3] - 2016-02-16
+  - Bug fixes
+
+## [0.2.2] - 2015-12-30
+  - Bug fixes
+
+## [0.2.1] -  2015-12-22
+  - Support for connection pooling support added through HikariCP
+  - Support for unsafe statement handling (allowing dynamic queries)
+  - Altered exception handling to now count sequential flushes with exceptions thrown

Gemfile

@@ -0,0 +1,2 @@
+source 'https://rubygems.org'
+gemspec

README.md

@@ -1,95 +1,69 @@
-# logstash-jdbc
-JDBC output plugin for Logstash.
+# logstash-output-jdbc 
+
+[![Build Status](https://travis-ci.org/theangryangel/logstash-output-jdbc.svg?branch=master)](https://travis-ci.org/theangryangel/logstash-output-jdbc)
+
 This plugin is provided as an external plugin and is not part of the Logstash project.
 
-Currently untested with logstash 1.5+. Support is planned.
+This plugin allows you to output to SQL databases, using JDBC adapters.
+See below for tested adapters, and example configurations.
 
-## Warning
 This has not yet been extensively tested with all JDBC drivers and may not yet work for you.
 
+If you do find this works for a JDBC driver without an example, let me know and provide a small example configuration if you can.
+
+This plugin does not bundle any JDBC jar files, and does expect them to be in a
+particular location. Please ensure you read the 4 installation lines below.
+
+## ChangeLog
+See CHANGELOG.md
+
+## Versions
+Released versions are available via rubygems, and typically tagged.
+
+For development:
+  - See master branch for logstash v5
+  - See v2.x branch for logstash v2
+  - See v1.5 branch for logstash v1.5 
+  - See v1.4 branch for logstash 1.4
+
 ## Installation
-  - Copy lib directory contents into your logstash installation.
-  - Create the directory vendor/jar/jdbc in your logstash installation (`mkdir -p vendor/jar/jdbc/`)
-  - Add JDBC jar files to vendor/jar/jdbc in your logstash installation
-  - Configure
+  - Run `bin/plugin install logstash-output-jdbc` in your logstash installation directory
+  - Now either:
+    - Use driver_jar_path in your configuraton to specify a path to your jar file
+  - Or:
+    - Create the directory vendor/jar/jdbc in your logstash installation (`mkdir -p vendor/jar/jdbc/`)
+    - Add JDBC jar files to vendor/jar/jdbc in your logstash installation
+  - And then configure (examples below)
+
+## Running tests
+At this time tests only run against Derby, in an in-memory database.
+Acceptance tests for individual database engines will be added over time.
+
+Assuming valid jruby is installed
+  - First time, issue `jruby -S bundle install` to install dependencies
+  - Next, download Derby jar from https://db.apache.org/derby/
+  - Run the tests `JDBC_DERBY_JAR=path/to/derby.jar jruby -S rspec`
+  - Optionally add the `JDBC_DEBUG=1` env variable to add logging to stdout
 
 ## Configuration options
-  * driver_class, string, JDBC driver class to load
-  * connection_string, string, JDBC connection string
-  * statement, array, an array of strings representing the SQL statement to run. Index 0 is the SQL statement that is prepared, all other array entries are passed in as parameters (in order). A parameter may either be a property of the event (i.e. "@timestamp", or "host") or a formatted string (i.e. "%{host} - %{message}" or "%{message}"). If a key is passed then it will be automatically converted as required for insertion into SQL. If it's a formatted string then it will be passed in verbatim.
-  * flush_size, number, default = 1000, number of entries to buffer before sending to SQL
-  * idle_flush_time, number, default = 1, number of idle seconds before sending data to SQL, even if the flush_size has not been reached. If you modify this value you should also consider altering max_repeat_exceptions_time
-  * max_repeat_exceptions, number, default = 5, number of times the same exception can repeat before we stop logstash. Set to a value less than 1 if you never want it to stop
-  * max_repeat_exceptions_time, number, default = 30, maxium number of seconds between exceptions before they're considered "different" exceptions. If you modify idle_flush_time you should consider this value
+
+| Option | Type | Description | Required? | Default |
+| ------ | ---- | ----------- | --------- | ------- |
+| driver_class | String | Specify a driver class if autoloading fails | No | |
+| driver_auto_commit | Boolean | If the driver does not support auto commit, you should set this to false | No | True |
+| driver_jar_path | String | File path to jar file containing your JDBC driver. This is optional, and all JDBC jars may be placed in $LOGSTASH_HOME/vendor/jar/jdbc instead. | No | |
+| connection_string | String | JDBC connection URL | Yes | |
+| username | String | JDBC username - this is optional as it may be included in the connection string, for many drivers | No | |
+| password | String | JDBC password - this is optional as it may be included in the connection string, for many drivers | No | |
+| statement | Array | An array of strings representing the SQL statement to run. Index 0 is the SQL statement that is prepared, all other array entries are passed in as parameters (in order). A parameter may either be a property of the event (i.e. "@timestamp", or "host") or a formatted string (i.e. "%{host} - %{message}" or "%{message}"). If a key is passed then it will be automatically converted as required for insertion into SQL. If it's a formatted string then it will be passed in verbatim. | Yes |  |
+| unsafe_statement | Boolean | If yes, the statement is evaluated for event fields - this allows you to use dynamic table names, etc. **This is highly dangerous** and you should **not** use this unless you are 100% sure that the field(s) you are passing in are 100% safe. Failure to do so will result in possible SQL injections. Please be aware that there is also a potential performance penalty as each event must be evaluated and inserted into SQL one at a time, where as when this is false multiple events are inserted at once. Example statement: [ "insert into %{table_name_field} (column) values(?)", "fieldname" ] | No | False |
+| max_pool_size | Number | Maximum number of connections to open to the SQL server at any 1 time | No | 5 |
+| connection_timeout | Number | Number of seconds before a SQL connection is closed | No | 2800 |
+| flush_size | Number | Maximum number of entries to buffer before sending to SQL - if this is reached before idle_flush_time | No | 1000 |
+| idle_flush_time | Number | Number of idle seconds before sending data to SQL - even if the flush_size has not yet been reached | No | 1 |
+| max_flush_exceptions | Number | Number of sequential flushes which cause an exception, before we stop logstash. Set to a value less than 1 if you never want it to stop. This should be carefully configured with relation to idle_flush_time if your SQL instance is not highly available. | No | 0 |
 
 ## Example configurations
-### SQLite3
-  * Tested using https://bitbucket.org/xerial/sqlite-jdbc
-  * SQLite setup - `echo "CREATE table log (host text, timestamp datetime, message text);" | sqlite3 test.db`
-```
-input
-{
-	stdin { }
-}
-output {
-	stdout { }
+Example logstash configurations, can now be found in the examples directory. Where possible we try to link every configuration with a tested jar.
 
-	jdbc {
-		driver_class => 'org.sqlite.JDBC'
-		connection_string => 'jdbc:sqlite:test.db'
-		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, ?, ?)", "host", "@timestamp", "message" ]
-	}
-}
-```
-
-### SQL Server
-  * Tested using http://msdn.microsoft.com/en-gb/sqlserver/aa937724.aspx
-```
-input
-{
-	stdin { }
-}
-output {
-	jdbc {
-		driver_class => 'com.microsoft.sqlserver.jdbc.SQLServerDriver'
-		connection_string => "jdbc:sqlserver://server:1433;databaseName=databasename;user=username;password=password;autoReconnect=true;"
-		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, ?, ?)", "host", "@timestamp", "message" ]
-	}
-}
-```
-
-### Postgres
-With thanks to [@roflmao](https://github.com/roflmao)
-```
-input
-{
-	stdin { }
-}
-output {
-	jdbc {
-		driver_class => 'org.postgresql.Driver'
-		connection_string => 'jdbc:postgresql://hostname:5432/database?user=username&password=password'
-		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, CAST (? AS timestamp), ?)", "host", "@timestamp", "message" ]
-	}
-}
-```
-
-### Oracle
-With thanks to [@josemazo](https://github.com/josemazo)
-  * Tested with Express Edition 11g Release 2
-  * Tested using http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html (ojdbc6.jar)
-```
-input
-{
-	stdin { }
-}
-output {
-	jdbc {
-		driver_class => "oracle.jdbc.driver.OracleDriver"
-		connection_string => "jdbc:oracle:thin:USER/PASS@HOST:PORT:SID"
-		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, CAST (? AS timestamp), ?)", "host", "@timestamp", "message" ]
-	}
-}
-```
-
-/* vim: set ts=4 sw=4 tw=0 :*/
+If you have a working sample configuration, for a DB thats not listed, pull requests are welcome.

Rakefile

@@ -0,0 +1 @@
+require "logstash/devutils/rake"

examples/apache-phoenix-hbase-sql.md

@@ -0,0 +1,16 @@
+# Example: Apache Phoenix (HBase SQL)
+  * Tested with Ubuntu 14.04.03 / Logstash 2.1 / Apache Phoenix 4.6
+  * <!> HBase and Zookeeper must be both accessible from logstash machine <!>
+```
+input
+{
+    stdin { }
+}
+output {
+    jdbc {
+        connection_string => "jdbc:phoenix:ZOOKEEPER_HOSTNAME"
+        statement => [ "UPSERT INTO EVENTS log (host, timestamp, message) VALUES(?, ?, ?)", "host", "@timestamp", "message" ]
+    }
+
+}
+```

examples/mariadb.md

@@ -0,0 +1,16 @@
+# Example: MariaDB
+  * Tested with Ubuntu 14.04.3 LTS, Server version: 10.1.9-MariaDB-1~trusty-log mariadb.org binary distribution
+  * Tested using https://downloads.mariadb.com/enterprise/tqge-whfa/connectors/java/connector-java-1.3.2/mariadb-java-client-1.3.2.jar (mariadb-java-client-1.3.2.jar)
+```
+input
+{
+    stdin { }
+}
+output {
+    jdbc {
+        connection_string => "jdbc:mariadb://HOSTNAME/DATABASE?user=USER&password=PASSWORD"
+        statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, ?, ?)", "host", "@timestamp", "message" ]
+    }
+
+}
+```

examples/mysql.md

@@ -0,0 +1,16 @@
+# Example: Mysql
+With thanks to [@jMonsinjon](https://github.com/jMonsinjon) 
+  * Tested with Version 14.14 Distrib 5.5.43, for debian-linux-gnu (x86_64)
+  * Tested using http://dev.mysql.com/downloads/file.php?id=457911 (mysql-connector-java-5.1.36-bin.jar)
+```
+input
+{
+	stdin { }
+}
+output {
+	jdbc {
+		connection_string => "jdbc:mysql://HOSTNAME/DATABASE?user=USER&password=PASSWORD"
+		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, CAST (? AS timestamp), ?)", "host", "@timestamp", "message" ]
+	}
+}
+```

examples/odps.md

@@ -0,0 +1,20 @@
+# Example: ODPS
+With thanks to [@onesuper](https://github.com/onesuper)
+```
+input
+{
+    stdin { }
+}
+output {
+    jdbc {
+        driver_class => "com.aliyun.odps.jdbc.OdpsDriver"
+        driver_auto_commit => false
+        connection_string => "jdbc:odps:http://service.odps.aliyun.com/api?project=meta_dev&loglevel=DEBUG"
+        username => "abcd"
+        password => "1234"
+        max_pool_size => 5
+        flush_size => 10
+        statement => [ "INSERT INTO test_logstash VALUES(?, ?, ?);", "host", "@timestamp", "message" ]
+    }
+}
+```

examples/oracle.md

@@ -0,0 +1,16 @@
+# Example: Oracle
+With thanks to [@josemazo](https://github.com/josemazo)
+  * Tested with Express Edition 11g Release 2
+  * Tested using http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html (ojdbc6.jar)
+```
+input
+{
+	stdin { }
+}
+output {
+	jdbc {
+		connection_string => "jdbc:oracle:thin:USER/PASS@HOST:PORT:SID"
+		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, CAST (? AS timestamp), ?)", "host", "@timestamp", "message" ]
+	}
+}
+```

examples/postgres.md

@@ -0,0 +1,15 @@
+# Example: Postgres
+With thanks to [@roflmao](https://github.com/roflmao)
+```
+input
+{
+	stdin { }
+}
+output {
+	jdbc {
+		connection_string => 'jdbc:postgresql://hostname:5432/database?user=username&password=password'
+		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, CAST (? AS timestamp), ?)", "host", "@timestamp", "message" ]
+	}
+}
+```
+

examples/sql-server.md

@@ -0,0 +1,14 @@
+# Example: SQL Server
+  * Tested using http://msdn.microsoft.com/en-gb/sqlserver/aa937724.aspx
+```
+input
+{
+	stdin { }
+}
+output {
+	jdbc {
+		connection_string => "jdbc:sqlserver://server:1433;databaseName=databasename;user=username;password=password;autoReconnect=true;"
+		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, ?, ?)", "host", "@timestamp", "message" ]
+	}
+}
+```

examples/sqlite.md

@@ -0,0 +1,17 @@
+# Example: SQLite3
+  * Tested using https://bitbucket.org/xerial/sqlite-jdbc
+  * SQLite setup - `echo "CREATE table log (host text, timestamp datetime, message text);" | sqlite3 test.db`
+```
+input
+{
+	stdin { }
+}
+output {
+	stdout { }
+
+	jdbc {
+		connection_string => 'jdbc:sqlite:test.db'
+		statement => [ "INSERT INTO log (host, timestamp, message) VALUES(?, ?, ?)", "host", "@timestamp", "message" ]
+	}
+}
+```

lib/logstash-output-jdbc_jars.rb

@@ -0,0 +1,5 @@
+# encoding: utf-8
+require 'logstash/environment'
+
+root_dir = File.expand_path(File.join(File.dirname(__FILE__), ".."))
+LogStash::Environment.load_runtime_jars! File.join(root_dir, "vendor")

lib/logstash-output-jdbc_ring-buffer.rb

@@ -0,0 +1,17 @@
+class RingBuffer < Array
+  attr_reader :max_size
+
+  def initialize(max_size, enum = nil)
+    @max_size = max_size
+    enum.each { |e| self << e } if enum
+  end
+
+  def <<(el)
+    if self.size < @max_size || @max_size.nil?
+      super
+    else
+      self.shift
+      self.push(el)
+    end
+  end
+end

lib/logstash/outputs/jdbc.rb

@@ -3,23 +3,72 @@ require "logstash/outputs/base"
 require "logstash/namespace"
 require "stud/buffer"
 require "java"
+require "logstash-output-jdbc_jars"
+require "logstash-output-jdbc_ring-buffer"
 
+# Write events to a SQL engine, using JDBC.
+#
+# It is upto the user of the plugin to correctly configure the plugin. This
+# includes correctly crafting the SQL statement, and matching the number of
+# parameters correctly.
 class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
   # Adds buffer support
   include Stud::Buffer
 
-  config_name "jdbc"
-  milestone 1
+  STRFTIME_FMT = '%Y-%m-%d %T.%L'.freeze
 
-  # Driver class
+  RETRYABLE_SQLSTATE_CLASSES = [
+    # Classes of retryable SQLSTATE codes
+    # Not all in the class will be retryable. However, this is the best that 
+    # we've got right now.
+    # If a custom state code is required, set it in retry_sql_states.
+    '08', # Connection Exception
+    '24', # Invalid Cursor State (Maybe retry-able in some circumstances)
+    '25', # Invalid Transaction State 
+    '40', # Transaction Rollback 
+    '53', # Insufficient Resources
+    '54', # Program Limit Exceeded (MAYBE)
+    '55', # Object Not In Prerequisite State
+    '57', # Operator Intervention
+    '58', # System Error
+  ].freeze
+
+  config_name "jdbc"
+
+  # Driver class - Reintroduced for https://github.com/theangryangel/logstash-output-jdbc/issues/26
   config :driver_class, :validate => :string
 
-  # connection string
+  # Does the JDBC driver support autocommit?
+  config :driver_auto_commit, :validate => :boolean, :default => true, :required => true
+
+  # Where to find the jar
+  # Defaults to not required, and to the original behaviour
+  config :driver_jar_path, :validate => :string, :required => false
+
+  # jdbc connection string
   config :connection_string, :validate => :string, :required => true
 
+  # jdbc username - optional, maybe in the connection string
+  config :username, :validate => :string, :required => false
+
+  # jdbc password - optional, maybe in the connection string
+  config :password, :validate => :string, :required => false
+
   # [ "insert into table (message) values(?)", "%{message}" ]
   config :statement, :validate => :array, :required => true
 
+  # If this is an unsafe statement, use event.sprintf
+  # This also has potential performance penalties due to having to create a 
+  # new statement for each event, rather than adding to the batch and issuing
+  # multiple inserts in 1 go
+  config :unsafe_statement, :validate => :boolean, :default => false
+
+  # Number of connections in the pool to maintain
+  config :max_pool_size, :validate => :number, :default => 5
+
+  # Connection timeout
+  config :connection_timeout, :validate => :number, :default => 10000
+
   # We buffer a certain number of events before flushing that out to SQL.
   # This setting controls how many events will be buffered before sending a
   # batch of events.
@@ -36,47 +85,43 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
   # a timely manner.
   #
   # If you change this value please ensure that you change
-  # max_repeat_exceptions_time accordingly.
+  # max_flush_exceptions accordingly.
   config :idle_flush_time, :validate => :number, :default => 1
 
-  # Maximum number of repeating (sequential) exceptions, before we stop retrying
+  # Maximum number of sequential flushes which encounter exceptions, before we stop retrying.
   # If set to < 1, then it will infinitely retry.
-  config :max_repeat_exceptions, :validate => :number, :default => 5
+  # 
+  # You should carefully tune this in relation to idle_flush_time if your SQL server
+  # is not highly available.
+  # i.e. If your idle_flush_time is 1, and your max_flush_exceptions is 200, and your SQL server takes
+  # longer than 200 seconds to reboot, then logstash will stop.
+  config :max_flush_exceptions, :validate => :number, :default => 0
 
-  # The max number of seconds since the last exception, before we consider it
-  # a different cause.
-  # This value should be carefully considered in respect to idle_flush_time.
-  config :max_repeat_exceptions_time, :validate => :number, :default => 30
+  config :max_repeat_exceptions, :obsolete => "This has been replaced by max_flush_exceptions - which behaves slightly differently. Please check the documentation."
+  config :max_repeat_exceptions_time, :obsolete => "This is no longer required"
 
   public
   def register
     @logger.info("JDBC - Starting up")
 
-    jarpath = File.join(File.dirname(__FILE__), "../../../vendor/jar/jdbc/*.jar")
-    @logger.info(jarpath)
-    Dir[jarpath].each do |jar|
-      @logger.debug("JDBC - Loaded jar", :jar => jar)
-      require jar
-    end
+    load_jar_files!
 
-    import @driver_class
-
-    driver = Object.const_get(@driver_class[@driver_class.rindex('.') + 1, @driver_class.length]).new
-    @connection = driver.connect(@connection_string, java.util.Properties.new)
-
-    @logger.debug("JDBC - Created connection", :driver => driver, :connection => @connection)
+    @exceptions_tracker = RingBuffer.new(@max_flush_exceptions)
 
     if (@flush_size > 1000)
-      @logger.warn("JDBC - Flush size is set to > 1000. May have performance penalties, depending on your SQL engine.")
+      @logger.warn("JDBC - Flush size is set to > 1000")
     end
 
-    @repeat_exception_count = 0
-    @last_exception_time = Time.now
-
-    if (@max_repeat_exceptions > 0) and ((@idle_flush_time * @max_repeat_exceptions) > @max_repeat_exceptions_time)
-      @logger.warn("JDBC - max_repeat_exceptions_time is set such that it may still permit a looping exception. You probably changed idle_flush_time. Considering increasing max_repeat_exceptions_time.")
+    if @statement.length < 1
+      @logger.error("JDBC - No statement provided. Configuration error.")
     end
 
+    if (!@unsafe_statement and @statement.length < 2) 
+      @logger.error("JDBC - Statement has no parameters. No events will be inserted into SQL as you're not passing any event data. Likely configuration error.")
+    end
+
+    setup_and_test_pool!
+
     buffer_initialize(
       :max_items => @flush_size,
       :max_interval => @idle_flush_time,
@@ -85,72 +130,214 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
   end
 
   def receive(event)
-    return unless output?(event)
+    return unless output?(event) or event.cancelled?
     return unless @statement.length > 0
 
     buffer_receive(event)
   end
 
   def flush(events, teardown=false)
-    statement = @connection.prepareStatement(@statement[0])
-
-    events.each do |event|
-      next if @statement.length < 2
-
-      @statement[1..-1].each_with_index do |i, idx|
-        case event[i]
-        when Time
-          # Most reliable solution, cross JDBC driver
-          statement.setString(idx + 1, event[i].iso8601())
-        when Fixnum, Integer
-          statement.setInt(idx + 1, event[i])
-        when Float
-          statement.setFloat(idx + 1, event[i])
-        when String
-          statement.setString(idx + 1, event[i])
-        else
-          statement.setString(idx + 1, event.sprintf(i))
-        end
-      end
-
-      statement.addBatch()
+    if @unsafe_statement == true
+      unsafe_flush(events, teardown)
+    else
+      safe_flush(events, teardown)
     end
-
-    begin
-      @logger.debug("JDBC - Sending SQL", :sql => statement.toString())
-      statement.executeBatch()
-    rescue => e
-      # Raising an exception will incur a retry from Stud::Buffer.
-      # Since the exceutebatch failed this should mean any events failed to be
-      # inserted will be re-run. We're going to log it for the lols anyway.
-      @logger.warn("JDBC - Exception. Will automatically retry", :exception => e)
-    end
-
-    statement.close()
   end
 
   def on_flush_error(e)
-    return if @max_repeat_exceptions < 1
+    return if @max_flush_exceptions < 1
 
-    if @last_exception == e.to_s
-      @repeat_exception_count += 1
-    else
-      @repeat_exception_count = 0
+    @exceptions_tracker << e.class
+
+    if @exceptions_tracker.reject { |i| i.nil? }.count >= @max_flush_exceptions
+      @logger.error("JDBC - max_flush_exceptions has been reached")
+      log_jdbc_exception(e)
+      raise LogStash::ShutdownSignal.new
     end
-
-    if (@repeat_exception_count >= @max_repeat_exceptions) and (Time.now - @last_exception_time) < @max_repeat_exceptions_time
-      @logger.error("JDBC - Exception repeated more than the maximum configured", :exception => e, :max_repeat_exceptions => @max_repeat_exceptions, :max_repeat_exceptions_time => @max_repeat_exceptions_time)
-      raise e
-    end
-
-    @last_exception_time = Time.now
-    @last_exception = e.to_s
   end
 
   def teardown
     buffer_flush(:final => true)
-    @connection.close()
+    @pool.close()
     super
   end
 
+  private
+
+  def setup_and_test_pool!  
+    # Setup pool
+    @pool = Java::ComZaxxerHikari::HikariDataSource.new
+
+    @pool.setAutoCommit(@driver_auto_commit)
+    @pool.setDriverClassName(@driver_class) if @driver_class
+
+    @pool.setJdbcUrl(@connection_string)
+
+    @pool.setUsername(@username) if @username
+    @pool.setPassword(@password) if @password
+
+    @pool.setMaximumPoolSize(@max_pool_size)
+    @pool.setConnectionTimeout(@connection_timeout)
+
+    validate_connection_timeout = (@connection_timeout / 1000) / 2
+
+    # Test connection
+    test_connection = @pool.getConnection()
+    unless test_connection.isValid(validate_connection_timeout)
+      @logger.error("JDBC - Connection is not valid. Please check connection string or that your JDBC endpoint is available.")
+    end
+    test_connection.close()
+  end
+
+  def load_jar_files!
+    # Load jar from driver path
+    unless @driver_jar_path.nil?
+      raise Exception.new("JDBC - Could not find jar file at given path. Check config.") unless File.exists? @driver_jar_path
+      require @driver_jar_path
+      return
+    end
+
+    # Revert original behaviour of loading from vendor directory
+    # if no path given
+    if ENV['LOGSTASH_HOME']
+      jarpath = File.join(ENV['LOGSTASH_HOME'], "/vendor/jar/jdbc/*.jar")
+    else
+      jarpath = File.join(File.dirname(__FILE__), "../../../vendor/jar/jdbc/*.jar")
+    end
+
+    @logger.debug("JDBC - jarpath", path: jarpath)
+
+    jars = Dir[jarpath]
+    raise Exception.new("JDBC - No jars found in jarpath. Have you read the README?") if jars.empty?
+
+    jars.each do |jar|
+      @logger.debug("JDBC - Loaded jar", :jar => jar)
+      require jar
+    end
+  end
+
+  def safe_flush(events, teardown=false)
+    connection = nil
+    statement = nil
+    
+    begin
+      connection = @pool.getConnection()
+    rescue => e
+      log_jdbc_exception(e)
+      raise
+    end
+
+    begin
+      statement = connection.prepareStatement(@statement[0])
+
+      events.each do |event|
+        next if event.cancelled?
+        next if @statement.length < 2
+        statement = add_statement_event_params(statement, event)
+
+        statement.addBatch()
+      end
+
+      statement.executeBatch()
+      statement.close()
+      @exceptions_tracker << nil
+    rescue => e
+      log_jdbc_exception(e)
+      if retry_exception?(e)
+        raise
+      end
+    ensure
+      statement.close() unless statement.nil?
+      connection.close() unless connection.nil?
+    end
+  end
+
+  def unsafe_flush(events, teardown=false)
+    connection = nil
+    statement = nil
+    begin
+      connection = @pool.getConnection()
+    rescue => e
+      log_jdbc_exception(e)
+      raise
+    end
+
+    begin
+      events.each do |event|
+        next if event.cancelled?
+
+        statement = connection.prepareStatement(event.sprintf(@statement[0]))
+        statement = add_statement_event_params(statement, event) if @statement.length > 1
+
+        statement.execute()
+
+        # cancel the event, since we may end up outputting the same event multiple times
+        # if an exception happens later down the line
+        event.cancel
+        @exceptions_tracker << nil
+      end
+    rescue => e
+      log_jdbc_exception(e)
+      if retry_exception?(e)
+        raise
+      end
+    ensure
+      statement.close() unless statement.nil?
+      connection.close() unless connection.nil?
+    end
+  end
+
+  def add_statement_event_params(statement, event)
+    @statement[1..-1].each_with_index do |i, idx|
+      case event[i]
+      when Time
+        # See LogStash::Timestamp, below, for the why behind strftime.
+        statement.setString(idx + 1, event[i].strftime(STRFTIME_FMT))
+      when LogStash::Timestamp
+        # XXX: Using setString as opposed to setTimestamp, because setTimestamp
+        # doesn't behave correctly in some drivers (Known: sqlite)
+        #
+        # Additionally this does not use `to_iso8601`, since some SQL databases
+        # choke on the 'T' in the string (Known: Derby).
+        #
+        # strftime appears to be the most reliable across drivers.
+        statement.setString(idx + 1, event[i].time.strftime(STRFTIME_FMT))
+      when Fixnum, Integer
+        statement.setInt(idx + 1, event[i])
+      when Float
+        statement.setFloat(idx + 1, event[i])
+      when String
+        statement.setString(idx + 1, event[i])
+      when true
+        statement.setBoolean(idx + 1, true)
+      when false
+        statement.setBoolean(idx + 1, false)
+      else
+        if event[i].nil? and i =~ /%\{/
+          statement.setString(idx + 1, event.sprintf(i))
+        else
+          statement.setString(idx + 1, nil)
+        end
+      end
+    end
+
+    statement
+  end
+
+  def log_jdbc_exception(exception)
+    current_exception = exception
+    loop do
+      @logger.error("JDBC Exception encountered: Will automatically retry.", :exception => current_exception)
+      current_exception = current_exception.getNextException()
+      break if current_exception == nil
+    end
+  end
+
+  def retry_exception?(exception)
+    if exception.respond_to? 'getSQLState'
+      return RETRYABLE_SQLSTATE_CLASSES.include?(e.getSQLState[0,2])
+    end
+
+    true
+  end
 end # class LogStash::Outputs::jdbc

logstash-output-jdbc.gemspec

@@ -0,0 +1,29 @@
+Gem::Specification.new do |s|
+  s.name = 'logstash-output-jdbc'
+  s.version = "0.2.8"
+  s.licenses = [ "Apache License (2.0)" ]
+  s.summary = "This plugin allows you to output to SQL, via JDBC"
+  s.description = "This gem is a logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/plugin install gemname. This gem is not a stand-alone program"
+  s.authors = ["the_angry_angel"]
+  s.email = "karl+github@theangryangel.co.uk"
+  s.homepage = "https://github.com/theangryangel/logstash-output-jdbc"
+  s.require_paths = [ "lib" ]
+
+  # Files
+  s.files = Dir.glob("{lib,vendor,spec}/**/*") + %w(LICENSE.txt README.md)
+
+   # Tests
+  s.test_files = s.files.grep(%r{^(test|spec|features)/})
+
+  # Special flag to let us know this is actually a logstash plugin
+  s.metadata = { "logstash_plugin" => "true", "logstash_group" => "output" }
+
+  # Gem dependencies
+  s.add_runtime_dependency "logstash-core", ">= 2.0.0.beta2", "< 3.0.0"
+  s.add_runtime_dependency 'stud'
+  s.add_runtime_dependency "logstash-codec-plain"
+  
+  s.add_development_dependency "logstash-devutils"
+
+  s.post_install_message = "logstash-output-jdbc 0.2.0 introduces several new features - please ensure you check the documentation in the README file"
+end

spec/outputs/jdbc_spec.rb

@@ -0,0 +1,94 @@
+require "logstash/devutils/rspec/spec_helper"
+require "logstash/outputs/jdbc"
+require "stud/temporary"
+require "java"
+
+describe LogStash::Outputs::Jdbc do
+
+  let(:derby_settings) do
+    { 
+      "driver_class" => "org.apache.derby.jdbc.EmbeddedDriver",
+      "connection_string" => "jdbc:derby:memory:testdb;create=true",
+      "driver_jar_path" => ENV['JDBC_DERBY_JAR'],
+      "statement" => [ "insert into log (created_at, message) values(?, ?)", "@timestamp" "message" ]
+    }
+  end
+
+  context 'rspec setup' do
+
+    it 'ensure derby is available' do
+      j = ENV['JDBC_DERBY_JAR']
+      expect(j).not_to be_nil, "JDBC_DERBY_JAR not defined, required to run tests"
+      expect(File.exists?(j)).to eq(true), "JDBC_DERBY_JAR defined, but not valid"
+    end
+    
+  end
+
+  context 'when initializing' do
+
+    it 'shouldn\'t register without a config' do
+      expect { 
+        LogStash::Plugin.lookup("output", "jdbc").new()
+      }.to raise_error(LogStash::ConfigurationError)
+    end
+
+    it 'shouldn\'t register with a missing jar file' do
+      derby_settings['driver_jar_path'] = nil
+      plugin = LogStash::Plugin.lookup("output", "jdbc").new(derby_settings)
+      expect { plugin.register }.to raise_error
+    end
+
+    it 'shouldn\'t register with a missing jar file' do
+      derby_settings['connection_string'] = nil
+      plugin = LogStash::Plugin.lookup("output", "jdbc").new(derby_settings)
+      expect { plugin.register }.to raise_error
+    end
+
+  end
+
+  context 'when outputting messages' do
+
+    let(:event_fields) do
+      { message: 'test-message' }
+    end
+    let(:event) { LogStash::Event.new(event_fields) }
+    let(:plugin) {
+      # Setup plugin
+      output = LogStash::Plugin.lookup("output", "jdbc").new(derby_settings)
+      output.register
+      if ENV['JDBC_DEBUG'] == '1'
+        output.logger.subscribe(STDOUT)
+      end
+
+      # Setup table
+      c = output.instance_variable_get(:@pool).getConnection()
+      stmt = c.createStatement()
+      stmt.executeUpdate("CREATE table log (created_at timestamp, message varchar(512))")
+      stmt.close()
+      c.close()
+
+      output
+    }
+
+    it 'should save a event' do
+      expect { plugin.receive(event) }.to_not raise_error
+      
+      # Wait for 1 second, for the buffer to flush
+      sleep 1
+
+      c = plugin.instance_variable_get(:@pool).getConnection()
+      stmt = c.createStatement()
+      rs = stmt.executeQuery("select count(*) as total from log")
+      count = 0
+      while rs.next()
+        count = rs.getInt("total")
+      end
+      stmt.close()
+      c.close()
+
+      expect(count).to be > 0
+    end
+
+  end
+
+end