remove advanced DataSource config from the default DataSource.groovy file, add link to Grails docs

Author: lhotari

grails-resources/src/grails/grails-app/conf/DataSource.groovy

@@ -31,9 +31,7 @@ environments {
             dbCreate = "update"
             url = "jdbc:h2:prodDb;MVCC=TRUE;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE"
             properties {
-               // Documentation for Tomcat JDBC Pool
-               // http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html#Common_Attributes
-               // https://tomcat.apache.org/tomcat-7.0-doc/api/org/apache/tomcat/jdbc/pool/PoolConfiguration.html
+               // See http://grails.org/doc/latest/guide/conf.html#dataSource for documentation
                jmxEnabled = true
                initialSize = 5
                maxActive = 50
@@ -49,51 +47,8 @@ environments {
                testOnBorrow = true
                testWhileIdle = true
                testOnReturn = false
-               ignoreExceptionOnPreLoad = true
-               // http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html#JDBC_interceptors
                jdbcInterceptors = "ConnectionState;StatementCache(max=200)"
-               defaultTransactionIsolation = java.sql.Connection.TRANSACTION_READ_COMMITTED // safe default
-               // controls for leaked connections 
-               abandonWhenPercentageFull = 100 // settings are active only when pool is full
-               removeAbandonedTimeout = 120000
-               removeAbandoned = true
-               // use JMX console to change this setting at runtime
-               logAbandoned = false // causes stacktrace recording overhead, use only for debugging
-               /*
-               // JDBC driver properties
-               // Mysql as example
-               dbProperties {
-                   // Mysql specific driver properties
-                   // http://dev.mysql.com/doc/connector-j/en/connector-j-reference-configuration-properties.html
-                   // let Tomcat JDBC Pool handle reconnecting
-                   autoReconnect=false
-                   // truncation behaviour 
-                   jdbcCompliantTruncation=false
-                   // mysql 0-date conversion
-                   zeroDateTimeBehavior='convertToNull'
-                   // Tomcat JDBC Pool's StatementCache is used instead, so disable mysql driver's cache
-                   cachePrepStmts=false
-                   cacheCallableStmts=false
-                   // Tomcat JDBC Pool's StatementFinalizer keeps track
-                   dontTrackOpenResources=true
-                   // performance optimization: reduce number of SQLExceptions thrown in mysql driver code
-                   holdResultsOpenOverStatementClose=true
-                   // enable MySQL query cache - using server prep stmts will disable query caching
-                   useServerPrepStmts=false
-                   // metadata caching
-                   cacheServerConfiguration=true
-                   cacheResultSetMetadata=true
-                   metadataCacheSize=100
-                   // timeouts for TCP/IP
-                   connectTimeout=15000
-                   socketTimeout=120000
-                   // timer tuning (disable)
-                   maintainTimeStats=false
-                   enableQueryTimeouts=false
-                   // misc tuning
-                   noDatetimeStringSync=true
-               }
-               */
+               defaultTransactionIsolation = java.sql.Connection.TRANSACTION_READ_COMMITTED
             }
         }
     }