A Clojure wrapper to HikariCP JDBC connection pool
Clojure
Latest commit 139704e Oct 3, 2016 @jstepien jstepien Version 1.7.5

README.md

hikari-cp

hikari-cp Circle CI

A Clojure wrapper to HikariCP - "zero-overhead" production ready JDBC connection pool.

Installation

Add the following dependency to your project.clj file:

[hikari-cp "1.7.5"]

Note: hikari-cp targets Java 8 by default. If you are using an older version of Java, your project.clj should look more like:

[hikari-cp-java6 "1.6.1"]

You'll also need to add the JDBC driver needed for your database.

Configuration options

Option Required Default value Description
:auto-commit No true This property controls the default auto-commit behavior of connections returned from the pool. It is a boolean value.
:read-only No false This property controls whether Connections obtained from the pool are in read-only mode by default.
:connection-timeout No 30000 This property controls the maximum number of milliseconds that a client will wait for a connection from the pool. If this time is exceeded without a connection becoming available, a SQLException will be thrown. 1000ms is the minimum value.
:validation-timeout No 5000 This property controls the maximum amount of time that a connection will be tested for aliveness. This value must be less than the :connection-timeout. The lowest accepted validation timeout is 1000ms (1 second).
:idle-timeout No 600000 This property controls the maximum amount of time (in milliseconds) that a connection is allowed to sit idle in the pool.
:max-lifetime No 1800000 This property controls the maximum lifetime of a connection in the pool. A value of 0 indicates no maximum lifetime (infinite lifetime).
:minimum-idle No 10 This property controls the minimum number of idle connections that HikariCP tries to maintain in the pool.
:maximum-pool-size No 10 This property controls the maximum size that the pool is allowed to reach, including both idle and in-use connections. Basically this value will determine the maximum number of actual connections to the database backend.
:pool-name No Auto-generated This property represents a user-defined name for the connection pool and appears mainly in logging and JMX management consoles to identify pools and pool configurations.
:jdbc-url Yes¹ None This property sets the JDBC connection URL.
:driver-class-name No None This property sets the JDBC driver class.
:adapter Yes¹ None This property sets the database adapter. Please check Adapters and corresponding datasource class names for the full list of supported adapters and their datasource class names.
:username No None This property sets the default authentication username used when obtaining Connections from the underlying driver.
:password No None This property sets the default authentication password used when obtaining Connections from the underlying driver.
:database-name No None This property sets the database name.
:server-name No Depends on the adapter This property sets the hostname client connects to.
:port-number No Depends on the adapter This property sets the port clients connects on.
:connection-test-query No None If your driver supports JDBC4 we strongly recommend not setting this property. This is for "legacy" databases that do not support the JDBC4 Connection.isValid() API. This is the query that will be executed just before a connection is given to you from the pool to validate that the connection to the database is still alive.
:leak-detection-threshold No 0 This property controls the amount of time that a connection can be out of the pool before a message is logged indicating a possible connection leak. A value of 0 means leak detection is disabled, minimum accepted value is 2000 (ms). ( ps: it's rarely needed option, use only for debugging )
:register-mbeans No false This property register mbeans which can be used in jmx to monitor hikari-cp.
:connection-init-sql No None This property sets a SQL statement that will be executed after every new connection creation before adding it to the pool.
:datasource No None This property allows you to directly set the instance of the DataSource to be wrapped by the pool.
:datasource-classname No None This is the name of the DataSource class provided by the JDBC driver.
:metric-registry No None This is an instance of a dropwizard metrics MetricsRegistry

¹ :adapter and :jdbc-url are mutually exclusive.

You can also add other datasource-specific configuration options. By default, keywords will be converted to the camelCase format add added as a datasource property, unless a special translation is defined:

;; {:tcp-keep-alive true} will be:
(.addDataSourceProperty config "tcpKeepAlive" true)

;; {:use-ssl false} has a custom translation, so it will be:
(.addDataSourceProperty config "useSSL" false)

Custom translations of properties can be added by extending the translate-property multimethod.

Please note: All time values are specified in milliseconds.

Adapters and corresponding datasource class names

Adapter Datasource class name Tested with hikari-cp
derby org.apache.derby.jdbc.ClientDataSource No
firebird org.firebirdsql.pool.FBSimpleDataSource No
db2 com.ibm.db2.jcc.DB2SimpleDataSource No
h2 org.h2.jdbcx.JdbcDataSource Yes
hsqldb org.hsqldb.jdbc.JDBCDataSource No
mariadb org.mariadb.jdbc.MySQLDataSource No
mysql com.mysql.jdbc.jdbc2.optional.MysqlDataSource Yes
sqlserver-jtds net.sourceforge.jtds.jdbcx.JtdsDataSource Yes
sqlserver com.microsoft.sqlserver.jdbc.SQLServerDataSource Yes
oracle oracle.jdbc.pool.OracleDataSource Yes
pgjdbc-ng com.impossibl.postgres.jdbc.PGDataSource No
postgresql org.postgresql.ds.PGSimpleDataSource Yes
fdbsql com.foundationdb.sql.jdbc.ds.FDBSimpleDataSource No
sybase com.sybase.jdbcx.SybDataSource No

Usage

PostgreSQL example

(ns hikari-cp.example
  (:require [hikari-cp.core :refer :all]
            [clojure.java.jdbc :as jdbc]))

(def datasource-options {:auto-commit        true
                         :read-only          false
                         :connection-timeout 30000
                         :validation-timeout 5000
                         :idle-timeout       600000
                         :max-lifetime       1800000
                         :minimum-idle       10
                         :maximum-pool-size  10
                         :pool-name          "db-pool"
                         :adapter            "postgresql"
                         :username           "username"
                         :password           "password"
                         :database-name      "database"
                         :server-name        "localhost"
                         :port-number        5432
                         :register-mbeans    false})

(def datasource
  (make-datasource datasource-options))

(defn -main [& args]
  (jdbc/with-db-connection [conn {:datasource datasource}]
    (let [rows (jdbc/query conn "SELECT * FROM table")]
      (println rows)))
  (close-datasource datasource))

H2 minimal config example

(def datasource-options {:adapter "h2"
                         :url     "jdbc:h2:~/test"})

Oracle example

(ns hikari-cp.example
  (:require [hikari-cp.core :refer :all]
            [clojure.java.jdbc :as jdbc]))

(def datasource-options {:username              "username"
                         :password              "password"
                         :database-name         "database"
                         :server-name           "localhost"
                         :port-number           1521
                         :driverType            "thin"       ; Other options are oci8, oci or kprb. See jdbc.pool.OracleDataSource.makeURL()
                         :adapter               "oracle"})

(def datasource
  (make-datasource datasource-options))

(defn -main [& args]
  (jdbc/with-db-connection [conn {:datasource datasource}]
    (let [rows (jdbc/query conn "SELECT * FROM table")]
      (println rows)))
  (close-datasource datasource))

Notice

make-datasource will throw IllegalArgumentException when invalid arguments are provided:

(make-datasource (dissoc config :username :database-name))
;; IllegalArgumentException: Invalid configuration options: (:username :database-name)

License

Copyright © 2014 - 2016 Tomek Wałkuski and Jan Stępień

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.