📄 database-tags.xtp
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<document><header> <title>database: Database tag configuration</title> <version>Resin 3.1</version> <description> <p>The <var>database</var> tag configures a database as a javax.sql.DataSource with numerous options. Resin offers robust database connection pooling. </p> </description></header><body><localtoc/><s1 title="See Also"><ul><li>See <a href="config-env.xtp">Environment</a> configuration for resources: classloader, databases, connectors, and resources.</li><li>See <a href="config-database.xtp">Database Configuration</a> for a detailed overview of databases and Resin.</li></ul></s1><defun title="<connection-wait-time>" version="Resin 3.1"><parents>database</parents><p><connection-wait-time> configures the time a <code>getConnection</code>call should wait when then pool is full before trying to create anoverflow connection.</p><default>10m</default></defun><defun title="<close-dangling-connections>" version="Resin 3.1.1"><parents>database</parents><p><close-dangling-connections> closes open connections at theend of a request and logs a warning and stack trace.</p><default>true</default></defun><defun title="<driver>" version="Resin 3.1"><parents>database</parents><p><driver> configures a database driver for a connection pool.The individual driver information is available from the driver vendoror in the <a href="db-thirdparty.xtp">database driver</a> page.</p><p>The content of the driver tag configures bean properties ofthe driver class, e.g. url, user, password.</p><def title="driver schema">element driver { type, *}</def></defun><defun title="<database>" version="Resin 3.1"><parents>resin, cluster, host, web-app</parents><p><database> configures a database as a <code>javax.sql.DataSource</code>and stores it in jndi with the given <var>jndi-name</var>.</p><deftable-childtags><tr> <td>connection-wait-time</td> <td>When the pool it full, how long to wait before opening a new connection anyway.</td> <td>10m</td></tr></deftable-childtags><example title="Example: mysql database"><web-app xmlns="http://caucho.com/ns/resin"> <database jndi-name="jdbc/test"> <driver type="com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource"> <url>jdbc:mysql://localhost:3306/test</url> <user></user> <password></password> </driver> </database></web-app></example><def title="database schema">element database { jndi-name & connection-Database? & driver+ & connection-wait-time & max-active-time & max-close-statements & max-connections & max-create-connections & max-idle-time & max-overflow-connections & max-pool-time & password & ping & ping-table & ping-query & ping-interval & prepared-statement-cache-size & save-allocation-stack-trace & spy & transaction-timeout & user & xa & xa-forbid-same-rm & wrap-statements}</def></defun><defun title="<max-active-time>" version="Resin 3.1"><parents>database</parents><p><max-active-time> configures the maximum time a connectioncan be active before Resin will automatically close it. Normally,the max-active-time should not be configured, since Resin willalso automatically close a connection at the end of a request.</p><p>Sites should generally leave max-active-time at the default.</p><default>6h</default></defun><defun title="<max-close-statements>" version="Resin 3.1"><parents>database</parents><p><max-close-statements> configures how many open statements Resinshould save to for the connection close. Since the JDBC<code>Connection.close()</code> call automatically closes any openstatements, Resin's database pool needs to keep track of any openstatements to close them in case the application has forgotten. The<max-close-statements> is primarily needed for older database driversimplementing the <code>java.sql.Driver</code> interface.</p><default>256</default></defun><defun title="<max-connections>" version="Resin 3.1"><parents>database</parents><p><max-connections> configures the maximum number ofopen connections allowed for Resin's database pool. Sitescan use <max-connections> to throttle the number of databaseconnections for an overloaded server. When <code>max-connections</code>is reached and an application calls <code>getConnection</code>, Resin willwait <a href="#connection-wait-time">connection-wait-time</a> or untila connection is freed before allocating a new connection.</p><default>128</default></defun><defun title="<max-create-connections>" version="Resin 3.1"><parents>database</parents><p><max-create-connections> configures the maximum number ofsimultaneous connection creations. Since connection creation is slowand database access can be spiky, Resin's pool limits the numberof new connections to the database at any time. Once a connectionhas succeeded, a new connection can proceed.</p><default>5</default></defun><defun title="<max-idle-time>" version="Resin 3.1"><parents>database</parents><p><max-idle-time> configures the maximum time a connectioncan remain idle before Resin automatically closes it. Since idle databasestie up resources, Resin will slowly close idle connections that are nolonger needed.</p><p>Higher values of <max-idle-time> will connections to remain in theidle pool for a longer time. Lower values will close idle connectionsmore quickly.</p><default>30s</default></defun><defun title="<max-pool-time>" version="Resin 3.1"><parents>database</parents><p><max-pool-time> configures the maximum time the connectioncan remain open. A connection could theoretically remain open, switchingbetween active and idle, for an indefinite time. The <max-pool-time>allows a site to limit to total time of that connection.</p><p>Most sites will leave <max-pool-time> at the default.</p><default>24h</default></defun><defun title="<password>" version="Resin 3.1"><parents>database</parents><p><password> configures the database connection password.Sites requiring additional security for their passwords can usethe <a href="env-tags.xtp#resin:type">resin:type</a> attributeto configure a password decoder.</p></defun><defun title="<ping>" version="Resin 3.1"><parents>database</parents><p><ping> enables connection validation. When <ping> is enabled,Resin will test the connection with <a href="#ping-query"><ping-query></a>or <a href="#ping-table"><ping-table></a> before returning a connectionto the user. If the connection fails the test, Resin will close it andreturn a new connection.</p><p>For efficiency, Resin will only validate the connection if ithas been idle for longer than <a href="#ping-interval"><ping-interval></a>.</p><default>false</default></defun><defun title="<ping-table>" version="Resin 3.1"><parents>database</parents><p><ping-table> configures the database table Resin shoulduse to verify if a connection is still valid when returned from the pool.</p></defun><defun title="<ping-query>" version="Resin 3.1"><parents>database</parents><p><ping-query> specifies the query to use for validating if adatabase connection is still valid when returned from the idle pool.</p></defun><defun title="<ping-interval>" version="Resin 3.1"><parents>database</parents><p><ping-interval> configures when Resin should validate anidle connection. Connections which have been idle for less than<ping-interval> are assumed to be still valid without validation.Connections idle for longer than <ping-interval> are validated.</p><p>Sites can force a validation by setting <ping-interval> to 0.</p><default>1s</default></defun><defun title="<prepared-statement-cache-size>" version="Resin 3.1"><parents>database</parents><p><prepared-statement-cache-size> configures how many preparedstatements Resin should cache for each connection. Caching preparedstatement can improve performance for some database drivers by avoidingrepeated parsing of the query SQL.</p><default>0</default></defun><defun title="<save-allocation-stack-trace>" version="Resin 3.1"><parents>database</parents><p><save-allocation-stack-trace> helps debugging application witha missing <code>Connection.close()</code> by saving the stack tracewhere the <code>Connection.getConnection()</code> was called. WhenResin detects that the connection has failed to close, it can thenprint the allocation stack trace, which is more informative fortracking down errors.</p></defun><defun title="<spy>" version="Resin 3.1"><parents>database</parents><p>The <spy> tag is a very useful logging tag for debugging databaseproblems. If <spy> is enabled, all database queries will be loggedat the "fine" level. Applications can use <spy> to debug unexpecteddatabase queries, or to improve query performance.</p><default>false</default><example title="Example: spy output">0.6:setString(1,1)0.6:executeQuery(select o.DATA from my_bean o where o.ID=?)</example></defun><defun title="<transaction-timeout>" version="Resin 3.1"><parents>database</parents><p><transaction-timeout> configures the maximum time a transactioncan be alive before a mandatory rollback.</p><default>-1</default></defun></body></document>⌨️ 快捷键说明
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