error c3p0 - bad pool size config start 3 min 5. using 5 as start

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error c3p0 - bad pool size config start 3 min 5. using 5 as start

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#1 by (1 votes)
#2 by (0 votes)

2

Hello everyone! can someone help me how to solve this error below? I tried a lot and nothing.

Error:

12-Dec-2017 20:27:27.908 INFO [http-nio-8084-exec-6] org.springframework.web.servlet.FrameworkServlet.initServletBean FrameworkServlet 'dispatcher': initialization completed in 1266 ms
12-Dec-2017 20:27:27.923 INFO [http-nio-8084-exec-6] org.apache.catalina.core.StandardContext.reload Reloading Context with name [/Head2Head] is completed
12-Dec-2017 20:27:39.276 INFO [MLog-Init-Reporter] com.mchange.v2.log.MLog. MLog clients using java 1.4+ standard logging.
12-Dec-2017 20:27:39.338 INFO [http-nio-8084-exec-2] com.mchange.v2.c3p0.C3P0Registry. Initializing c3p0-0.9.5.2 [built 08-December-2015 22:06:04 -0800; debug? true; trace: 10]
12-Dec-2017 20:27:39.448 INFO [http-nio-8084-exec-2] com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource. Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 5, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, contextClassLoaderSource -> caller, dataSourceName -> 1hge5tw9sldokl6qlaopl|1f977041, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, extensions -> {}, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, forceSynchronousCheckins -> false, forceUseNamedDriverClass -> false, identityToken -> 1hge5tw9sldokl6qlaopl|1f977041, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> jdbc:mysql://*****************.sa-east-1.rds.amazonaws.com:3306/nadalspringmvc?autoReconnect=true&useSSL=false, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 100, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 10, numHelperThreads -> 3, preferredTestQuery -> null, privilegeSpawnedThreads -> false, properties -> {user=******, password=******}, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, testConnectionOnCheckin -> true, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, userOverrides -> {}, usesTraditionalReflectiveProxies -> false ]
12-Dec-2017 20:27:39.465 WARNING [http-nio-8084-exec-2] com.mchange.v2.resourcepool.BasicResourcePool. Bad pool size config, start 3 < min 10. Using 10 as start.

Code:

package br.com.head2head.dao;

import java.beans.PropertyVetoException;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;

public class ConnectionPool {

    private static final String DB_USERNAME = "********";
    private static final String DB_PASSWORD = "********";
    private static final String DB_URL = "jdbc:mysql://********.sa-east-1.rds.amazonaws.com:3306/********?autoReconnect=true&useSSL=false";
    private static final String DB_DRIVER_CLASS = "com.mysql.jdbc.Driver";

    private static ComboPooledDataSource dataSource;

    static {
        try {
            dataSource = new ComboPooledDataSource();
            dataSource.setDriverClass(DB_DRIVER_CLASS);

            dataSource.setJdbcUrl(DB_URL);
            dataSource.setUser(DB_USERNAME);
            dataSource.setPassword(DB_PASSWORD);

            dataSource.setMinPoolSize(100);
            dataSource.setMaxPoolSize(1000);
            dataSource.setAcquireIncrement(5);

        } catch (PropertyVetoException e) {
            e.printStackTrace();
        }
    }

    public static DataSource getDataSource() {
        return dataSource;
    }
}

java spring

asked by anonymous 13.12.2017 / 00:38

2 answers

0

It is only a warning that the initial value of the pool size is less than the minimum size of the pool (start 3

13.12.2017 / 11:20

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score 1 · Accepted Answer

It's not an error, it's just an alert, apparently you're not setting the initial value for the dataSource.

By default the initial value is 3, and by this excerpt:

if ( start < min ){
    if ( logger.isLoggable( MLevel.WARNING ) )
        logger.log( MLevel.WARNING, "Bad pool size config, start " + start + " < min " + min + ". Using " + min + " as start." );
        start = min;
    }
}

From BasicResourcePool available in Git (line 291) .

To fix you have two options:

1 - Decrease the min pool size to a value less than the initial (default = 3)

dataSource.setMinPoolSize(2);
2 - Or raise the initial poolSize to a value greater than min

dataSource.setInitialPoolSize(101);

More remembering again, this is only a warning , and according to the code above it will set the initial value as the minimum value ( start = min; ) when displaying this warning.

In practice your application will continue to function normally.

Another thing, if you are using spring-boot you can set the datasource pool to application.yml :

spring:  
  datasource:
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://********.sa-east-1.rds.amazonaws.com:3306/********?autoReconnect=true&useSSL=false
    username: ********
    password: ********
    validationQuery: SELECT 1
  jpa:
    show-sql: false
    hibernate:
      ddl-auto: update
      naming-strategy: org.hibernate.cfg.ImprovedNamingStrategy
      enable_lazy_load_no_trans: true
    properties:
      hibernate:
        dialect: org.hibernate.dialect.MySQLDialect
        c3p0:
          acquire_increment: 5
          idle_test_period: 3000
          max_size: 1000
          max_statements: 300
          min_size: 100
          timeout: 500
          validate: false