HikariCP实战 | 通过查看源码分析如何解决maxLifeTime配置问题

1、追本溯源

很多年前在stackoverflow上写过一篇文章：
https://stackoverflow.com/questions/28180562/hikaricp-and-maxlifetime#

hikariCP是非常优秀的JDBC connection pool. 官方配置：https://github.com/brettwooldridge/HikariCP

2、解决hikariCP的maxLifetime配置出现以下warn问题

WARN com.zaxxer.hikari.HikariConfig - maxLifetime is less than 120000ms, using default 1800000ms.

3、具体解决步骤（查看源码）

i don’t know your HikariCP Version, but in the version 2.2.4 you will find the reason why it will throw the above warning.

HikariConfig.class (in the com.zaxxer.hikari.HikariConfig):

 private void More ...validateNumerics()
  {
     Logger logger = LoggerFactory.getLogger(getClass());

     if (connectionTimeout == Integer.MAX_VALUE) {
        logger.warn("No connection wait timeout is set, this might cause an infinite wait.");
     }

     if (minIdle < 0 || minIdle > maxPoolSize) {
        minIdle = maxPoolSize;
     }

     if (maxLifetime < 0) {
        logger.error("maxLifetime cannot be negative.");
        throw new IllegalArgumentException("maxLifetime cannot be negative.");
     }
     else if (maxLifetime > 0 && maxLifetime < TimeUnit.SECONDS.toMillis(120)) {
        logger.warn("maxLifetime is less than 120000ms, using default {}ms.", MAX_LIFETIME);
        maxLifetime = MAX_LIFETIME;
     }

     if (idleTimeout != 0 && idleTimeout < TimeUnit.SECONDS.toMillis(30)) {
        logger.warn("idleTimeout is less than 30000ms, using default {}ms.", IDLE_TIMEOUT);
        idleTimeout = IDLE_TIMEOUT;
     }
     else if (idleTimeout > maxLifetime && maxLifetime > 0) {
        logger.warn("idleTimeout is greater than maxLifetime, setting to maxLifetime.");
        idleTimeout = maxLifetime;
     }

from this code, the maxLifeTime is at least 120000ms, using default 1800000ms. so you can’t set the maxLifeTime to 30000ms(30*1000). I guess your HikariCP version is at least older than 2.2.4.

But when you find the latest HikariCP version 2.7.4. it said “We strongly recommend setting this value, and it should be at least 30 seconds less than any database or infrastructure imposed connection time limit.”

the same class HikariConfig.class:

private void validateNumerics() {
    if(this.maxLifetime != 0L && this.maxLifetime < TimeUnit.SECONDS.toMillis(30L)) {
        LOGGER.warn("{} - maxLifetime is less than 30000ms, setting to default {}ms.", this.poolName, Long.valueOf(MAX_LIFETIME));
        this.maxLifetime = MAX_LIFETIME;
    }

    if(this.idleTimeout + TimeUnit.SECONDS.toMillis(1L) > this.maxLifetime && this.maxLifetime > 0L) {
        LOGGER.warn("{} - idleTimeout is close to or more than maxLifetime, disabling it.", this.poolName);
        this.idleTimeout = 0L;
    }

    if(this.idleTimeout != 0L && this.idleTimeout < TimeUnit.SECONDS.toMillis(10L)) {
        LOGGER.warn("{} - idleTimeout is less than 10000ms, setting to default {}ms.", this.poolName, Long.valueOf(IDLE_TIMEOUT));
        this.idleTimeout = IDLE_TIMEOUT;
    }

    if(this.leakDetectionThreshold > 0L && !unitTest && (this.leakDetectionThreshold < TimeUnit.SECONDS.toMillis(2L) || this.leakDetectionThreshold > this.maxLifetime && this.maxLifetime > 0L)) {
        LOGGER.warn("{} - leakDetectionThreshold is less than 2000ms or more than maxLifetime, disabling it.", this.poolName);
        this.leakDetectionThreshold = 0L;
    }

    if(this.connectionTimeout < 250L) {
        LOGGER.warn("{} - connectionTimeout is less than 250ms, setting to {}ms.", this.poolName, Long.valueOf(CONNECTION_TIMEOUT));
        this.connectionTimeout = CONNECTION_TIMEOUT;
    }

    if(this.validationTimeout < 250L) {
        LOGGER.warn("{} - validationTimeout is less than 250ms, setting to {}ms.", this.poolName, Long.valueOf(VALIDATION_TIMEOUT));
        this.validationTimeout = VALIDATION_TIMEOUT;
    }

    if(this.maxPoolSize < 1) {
        this.maxPoolSize = this.minIdle <= 0?10:this.minIdle;
    }

    if(this.minIdle < 0 || this.minIdle > this.maxPoolSize) {
        this.minIdle = this.maxPoolSize;
    }

}

完整代码看这里：
https://github.com/brettwooldridge/HikariCP/blob/dev/src/main/java/com/zaxxer/hikari/HikariConfig.java

/*
 * Copyright (C) 2013, 2014 Brett Wooldridge
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.zaxxer.hikari;

import com.codahale.metrics.health.HealthCheckRegistry;
import com.zaxxer.hikari.metrics.MetricsTrackerFactory;
import com.zaxxer.hikari.util.PropertyElf;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.lang.reflect.Modifier;
import java.security.AccessControlException;
import java.sql.Connection;
import java.util.Properties;
import java.util.TreeSet;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadLocalRandom;

import static com.zaxxer.hikari.util.UtilityElf.getNullIfEmpty;
import static com.zaxxer.hikari.util.UtilityElf.safeIsAssignableFrom;
import static java.util.concurrent.TimeUnit.MINUTES;
import static java.util.concurrent.TimeUnit.SECONDS;

@SuppressWarnings({"SameParameterValue", "unused"})
public class HikariConfig implements HikariConfigMXBean
{
   private static final Logger LOGGER = LoggerFactory.getLogger(HikariConfig.class);

   private static final char[] ID_CHARACTERS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
   private static final long CONNECTION_TIMEOUT = SECONDS.toMillis(30);
   private static final long VALIDATION_TIMEOUT = SECONDS.toMillis(5);
   private static final long SOFT_TIMEOUT_FLOOR = Long.getLong("com.zaxxer.hikari.timeoutMs.floor", 250L);
   private static final long IDLE_TIMEOUT = MINUTES.toMillis(10);
   private static final long MAX_LIFETIME = MINUTES.toMillis(30);
   private static final long DEFAULT_KEEPALIVE_TIME = 0L;
   private static final int DEFAULT_POOL_SIZE = 10;

   private static boolean unitTest = false;

   // Properties changeable at runtime through the HikariConfigMXBean
   //
   private volatile String catalog;
   private volatile long connectionTimeout;
   private volatile long validationTimeout;
   private volatile long idleTimeout;
   private volatile long leakDetectionThreshold;
   private volatile long maxLifetime;
   private volatile int maxPoolSize;
   private volatile int minIdle;
   private volatile String username;
   private volatile String password;

   // Properties NOT changeable at runtime
   //
   private long initializationFailTimeout;
   private String connectionInitSql;
   private String connectionTestQuery;
   private String dataSourceClassName;
   private String dataSourceJndiName;
   private String driverClassName;
   private String exceptionOverrideClassName;
   private String jdbcUrl;
   private String poolName;
   private String schema;
   private String transactionIsolationName;
   private boolean isAutoCommit;
   private boolean isReadOnly;
   private boolean isIsolateInternalQueries;
   private boolean isRegisterMbeans;
   private boolean isAllowPoolSuspension;
   private DataSource dataSource;
   private Properties dataSourceProperties;
   private ThreadFactory threadFactory;
   private ScheduledExecutorService scheduledExecutor;
   private MetricsTrackerFactory metricsTrackerFactory;
   private Object metricRegistry;
   private Object healthCheckRegistry;
   private Properties healthCheckProperties;

   private long keepaliveTime;

   private volatile boolean sealed;

   /**
    * Default constructor
    * 

    * If the System property {@code hikari.configurationFile} is set,
    * then the default constructor will attempt to load the specified configuration file
    * 

    * {@link #HikariConfig(String propertyFileName)} can be similarly used
    * instead of using the system property
    */
   public HikariConfig()
   {
      dataSourceProperties = new Properties();
      healthCheckProperties = new Properties();

      minIdle = -1;
      maxPoolSize = -1;
      maxLifetime = MAX_LIFETIME;
      connectionTimeout = CONNECTION_TIMEOUT;
      validationTimeout = VALIDATION_TIMEOUT;
      idleTimeout = IDLE_TIMEOUT;
      initializationFailTimeout = 1;
      isAutoCommit = true;
      keepaliveTime = DEFAULT_KEEPALIVE_TIME;

      var systemProp = System.getProperty("hikaricp.configurationFile");
      if (systemProp != null) {
         loadProperties(systemProp);
      }
   }

   /**
    * Construct a HikariConfig from the specified properties object.
    *
    * @param properties the name of the property file
    */
   public HikariConfig(Properties properties)
   {
      this();
      PropertyElf.setTargetFromProperties(this, properties);
   }

   /**
    * Construct a HikariConfig from the specified property file name.  propertyFileName
    * will first be treated as a path in the file-system, and if that fails the
    * Class.getResourceAsStream(propertyFileName) will be tried.
    *
    * @param propertyFileName the name of the property file
    */
   public HikariConfig(String propertyFileName)
   {
      this();

      loadProperties(propertyFileName);
   }

   // ***********************************************************************
   //                       HikariConfigMXBean methods
   // ***********************************************************************

   /** {@inheritDoc} */
   @Override
   public String getCatalog()
   {
      return catalog;
   }

   /** {@inheritDoc} */
   @Override
   public void setCatalog(String catalog)
   {
      this.catalog = catalog;
   }


   /** {@inheritDoc} */
   @Override
   public long getConnectionTimeout()
   {
      return connectionTimeout;
   }

   /** {@inheritDoc} */
   @Override
   public void setConnectionTimeout(long connectionTimeoutMs)
   {
      if (connectionTimeoutMs == 0) {
         this.connectionTimeout = Integer.MAX_VALUE;
      }
      else if (connectionTimeoutMs < SOFT_TIMEOUT_FLOOR) {
         throw new IllegalArgumentException("connectionTimeout cannot be less than " + SOFT_TIMEOUT_FLOOR + "ms");
      }
      else {
         this.connectionTimeout = connectionTimeoutMs;
      }
   }

   /** {@inheritDoc} */
   @Override
   public long getIdleTimeout()
   {
      return idleTimeout;
   }

   /** {@inheritDoc} */
   @Override
   public void setIdleTimeout(long idleTimeoutMs)
   {
      if (idleTimeoutMs < 0) {
         throw new IllegalArgumentException("idleTimeout cannot be negative");
      }
      this.idleTimeout = idleTimeoutMs;
   }

   /** {@inheritDoc} */
   @Override
   public long getLeakDetectionThreshold()
   {
      return leakDetectionThreshold;
   }

   /** {@inheritDoc} */
   @Override
   public void setLeakDetectionThreshold(long leakDetectionThresholdMs)
   {
      this.leakDetectionThreshold = leakDetectionThresholdMs;
   }

   /** {@inheritDoc} */
   @Override
   public long getMaxLifetime()
   {
      return maxLifetime;
   }

   /** {@inheritDoc} */
   @Override
   public void setMaxLifetime(long maxLifetimeMs)
   {
      this.maxLifetime = maxLifetimeMs;
   }

   /** {@inheritDoc} */
   @Override
   public int getMaximumPoolSize()
   {
      return maxPoolSize;
   }

   /** {@inheritDoc} */
   @Override
   public void setMaximumPoolSize(int maxPoolSize)
   {
      if (maxPoolSize < 1) {
         throw new IllegalArgumentException("maxPoolSize cannot be less than 1");
      }
      this.maxPoolSize = maxPoolSize;
   }

   /** {@inheritDoc} */
   @Override
   public int getMinimumIdle()
   {
      return minIdle;
   }

   /** {@inheritDoc} */
   @Override
   public void setMinimumIdle(int minIdle)
   {
      if (minIdle < 0) {
         throw new IllegalArgumentException("minimumIdle cannot be negative");
      }
      this.minIdle = minIdle;
   }

   /**
    * Get the default password to use for DataSource.getConnection(username, password) calls.
    * @return the password
    */
   public String getPassword()
   {
      return password;
   }

   /**
    * Set the default password to use for DataSource.getConnection(username, password) calls.
    * @param password the password
    */
   @Override
   public void setPassword(String password)
   {
      this.password = password;
   }

   /**
    * Get the default username used for DataSource.getConnection(username, password) calls.
    *
    * @return the username
    */
   public String getUsername()
   {
      return username;
   }

   /**
    * Set the default username used for DataSource.getConnection(username, password) calls.
    *
    * @param username the username
    */
   @Override
   public void setUsername(String username)
   {
      this.username = username;
   }

   /** {@inheritDoc} */
   @Override
   public long getValidationTimeout()
   {
      return validationTimeout;
   }

   /** {@inheritDoc} */
   @Override
   public void setValidationTimeout(long validationTimeoutMs)
   {
      if (validationTimeoutMs < SOFT_TIMEOUT_FLOOR) {
         throw new IllegalArgumentException("validationTimeout cannot be less than " + SOFT_TIMEOUT_FLOOR + "ms");
      }

      this.validationTimeout = validationTimeoutMs;
   }

   // ***********************************************************************
   //                     All other configuration methods
   // ***********************************************************************

   /**
    * Get the SQL query to be executed to test the validity of connections.
    *
    * @return the SQL query string, or null
    */
   public String getConnectionTestQuery()
   {
      return connectionTestQuery;
   }

   /**
    * Set the SQL query to be executed to test the validity of connections. Using
    * the JDBC4 Connection.isValid() method to test connection validity can
    * be more efficient on some databases and is recommended.
    *
    * @param connectionTestQuery a SQL query string
    */
   public void setConnectionTestQuery(String connectionTestQuery)
   {
      checkIfSealed();
      this.connectionTestQuery = connectionTestQuery;
   }

   /**
    * Get the SQL string that will be executed on all new connections when they are
    * created, before they are added to the pool.
    *
    * @return the SQL to execute on new connections, or null
    */
   public String getConnectionInitSql()
   {
      return connectionInitSql;
   }

   /**
    * Set the SQL string that will be executed on all new connections when they are
    * created, before they are added to the pool.  If this query fails, it will be
    * treated as a failed connection attempt.
    *
    * @param connectionInitSql the SQL to execute on new connections
    */
   public void setConnectionInitSql(String connectionInitSql)
   {
      checkIfSealed();
      this.connectionInitSql = connectionInitSql;
   }

   /**
    * Get the {@link DataSource} that has been explicitly specified to be wrapped by the
    * pool.
    *
    * @return the {@link DataSource} instance, or null
    */
   public DataSource getDataSource()
   {
      return dataSource;
   }

   /**
    * Set a {@link DataSource} for the pool to explicitly wrap.  This setter is not
    * available through property file based initialization.
    *
    * @param dataSource a specific {@link DataSource} to be wrapped by the pool
    */
   public void setDataSource(DataSource dataSource)
   {
      checkIfSealed();
      this.dataSource = dataSource;
   }

   /**
    * Get the name of the JDBC {@link DataSource} class used to create Connections.
    *
    * @return the fully qualified name of the JDBC {@link DataSource} class
    */
   public String getDataSourceClassName()
   {
      return dataSourceClassName;
   }

   /**
    * Set the fully qualified class name of the JDBC {@link DataSource} that will be used create Connections.
    *
    * @param className the fully qualified name of the JDBC {@link DataSource} class
    */
   public void setDataSourceClassName(String className)
   {
      checkIfSealed();
      this.dataSourceClassName = className;
   }

   /**
    * Add a property (name/value pair) that will be used to configure the {@link DataSource}/{@link java.sql.Driver}.
    *
    * In the case of a {@link DataSource}, the property names will be translated to Java setters following the Java Bean
    * naming convention.  For example, the property {@code cachePrepStmts} will translate into {@code setCachePrepStmts()}
    * with the {@code value} passed as a parameter.
    *
    * In the case of a {@link java.sql.Driver}, the property will be added to a {@link Properties} instance that will
    * be passed to the driver during {@link java.sql.Driver#connect(String, Properties)} calls.
    *
    * @param propertyName the name of the property
    * @param value the value to be used by the DataSource/Driver
    */
   public void addDataSourceProperty(String propertyName, Object value)
   {
      checkIfSealed();
      dataSourceProperties.put(propertyName, value);
   }

   public String getDataSourceJNDI()
   {
      return this.dataSourceJndiName;
   }

   public void setDataSourceJNDI(String jndiDataSource)
   {
      checkIfSealed();
      this.dataSourceJndiName = jndiDataSource;
   }

   public Properties getDataSourceProperties()
   {
      return dataSourceProperties;
   }

   public void setDataSourceProperties(Properties dsProperties)
   {
      checkIfSealed();
      dataSourceProperties.putAll(dsProperties);
   }

   public String getDriverClassName()
   {
      return driverClassName;
   }

   public void setDriverClassName(String driverClassName)
   {
      checkIfSealed();

      var driverClass = attemptFromContextLoader(driverClassName);
      try {
         if (driverClass == null) {
            driverClass = this.getClass().getClassLoader().loadClass(driverClassName);
            LOGGER.debug("Driver class {} found in the HikariConfig class classloader {}", driverClassName, this.getClass().getClassLoader());
         }
      } catch (ClassNotFoundException e) {
         LOGGER.error("Failed to load driver class {} from HikariConfig class classloader {}", driverClassName, this.getClass().getClassLoader());
      }

      if (driverClass == null) {
         throw new RuntimeException("Failed to load driver class " + driverClassName + " in either of HikariConfig class loader or Thread context classloader");
      }

      try {
         driverClass.getConstructor().newInstance();
         this.driverClassName = driverClassName;
      }
      catch (Exception e) {
         throw new RuntimeException("Failed to instantiate class " + driverClassName, e);
      }
   }

   public String getJdbcUrl()
   {
      return jdbcUrl;
   }

   public void setJdbcUrl(String jdbcUrl)
   {
      checkIfSealed();
      this.jdbcUrl = jdbcUrl;
   }

   /**
    * Get the default auto-commit behavior of connections in the pool.
    *
    * @return the default auto-commit behavior of connections
    */
   public boolean isAutoCommit()
   {
      return isAutoCommit;
   }

   /**
    * Set the default auto-commit behavior of connections in the pool.
    *
    * @param isAutoCommit the desired auto-commit default for connections
    */
   public void setAutoCommit(boolean isAutoCommit)
   {
      checkIfSealed();
      this.isAutoCommit = isAutoCommit;
   }

   /**
    * Get the pool suspension behavior (allowed or disallowed).
    *
    * @return the pool suspension behavior
    */
   public boolean isAllowPoolSuspension()
   {
      return isAllowPoolSuspension;
   }

   /**
    * Set whether or not pool suspension is allowed.  There is a performance
    * impact when pool suspension is enabled.  Unless you need it (for a
    * redundancy system for example) do not enable it.
    *
    * @param isAllowPoolSuspension the desired pool suspension allowance
    */
   public void setAllowPoolSuspension(boolean isAllowPoolSuspension)
   {
      checkIfSealed();
      this.isAllowPoolSuspension = isAllowPoolSuspension;
   }

   /**
    * Get the pool initialization failure timeout.  See {@code #setInitializationFailTimeout(long)}
    * for details.
    *
    * @return the number of milliseconds before the pool initialization fails
    * @see HikariConfig#setInitializationFailTimeout(long)
    */
   public long getInitializationFailTimeout()
   {
      return initializationFailTimeout;
   }

   /**
    * Set the pool initialization failure timeout.  This setting applies to pool
    * initialization when {@link HikariDataSource} is constructed with a {@link HikariConfig},
    * or when {@link HikariDataSource} is constructed using the no-arg constructor
    * and {@link HikariDataSource#getConnection()} is called.
    * 

    *   
Any value greater than zero will be treated as a timeout for pool initialization.
    *       The calling thread will be blocked from continuing until a successful connection
    *       to the database, or until the timeout is reached.  If the timeout is reached, then
    *       a {@code PoolInitializationException} will be thrown. 
    *   
A value of zero will not  prevent the pool from starting in the
    *       case that a connection cannot be obtained. However, upon start the pool will
    *       attempt to obtain a connection and validate that the {@code connectionTestQuery}
    *       and {@code connectionInitSql} are valid.  If those validations fail, an exception
    *       will be thrown.  If a connection cannot be obtained, the validation is skipped
    *       and the the pool will start and continue to try to obtain connections in the
    *       background.  This can mean that callers to {@code DataSource#getConnection()} may
    *       encounter exceptions. 
    *   
A value less than zero will bypass any connection attempt and validation during
    *       startup, and therefore the pool will start immediately.  The pool will continue to
    *       try to obtain connections in the background. This can mean that callers to
    *       {@code DataSource#getConnection()} may encounter exceptions. 
    * 
    * Note that if this timeout value is greater than or equal to zero (0), and therefore an
    * initial connection validation is performed, this timeout does not override the
    * {@code connectionTimeout} or {@code validationTimeout}; they will be honored before this
    * timeout is applied.  The default value is one millisecond.
    *
    * @param initializationFailTimeout the number of milliseconds before the
    *        pool initialization fails, or 0 to validate connection setup but continue with
    *        pool start, or less than zero to skip all initialization checks and start the
    *        pool without delay.
    */
   public void setInitializationFailTimeout(long initializationFailTimeout)
   {
      checkIfSealed();
      this.initializationFailTimeout = initializationFailTimeout;
   }

   /**
    * Determine whether internal pool queries, principally aliveness checks, will be isolated in their own transaction
    * via {@link Connection#rollback()}.  Defaults to {@code false}.
    *
    * @return {@code true} if internal pool queries are isolated, {@code false} if not
    */
   public boolean isIsolateInternalQueries()
   {
      return isIsolateInternalQueries;
   }

   /**
    * Configure whether internal pool queries, principally aliveness checks, will be isolated in their own transaction
    * via {@link Connection#rollback()}.  Defaults to {@code false}.
    *
    * @param isolate {@code true} if internal pool queries should be isolated, {@code false} if not
    */
   public void setIsolateInternalQueries(boolean isolate)
   {
      checkIfSealed();
      this.isIsolateInternalQueries = isolate;
   }

   public MetricsTrackerFactory getMetricsTrackerFactory()
   {
      return metricsTrackerFactory;
   }

   public void setMetricsTrackerFactory(MetricsTrackerFactory metricsTrackerFactory)
   {
      if (metricRegistry != null) {
         throw new IllegalStateException("cannot use setMetricsTrackerFactory() and setMetricRegistry() together");
      }

      this.metricsTrackerFactory = metricsTrackerFactory;
   }

   /**
    * Get the MetricRegistry instance to use for registration of metrics used by HikariCP.  Default is {@code null}.
    *
    * @return the MetricRegistry instance that will be used
    */
   public Object getMetricRegistry()
   {
      return metricRegistry;
   }

   /**
    * Set a MetricRegistry instance to use for registration of metrics used by HikariCP.
    *
    * @param metricRegistry the MetricRegistry instance to use
    */
   public void setMetricRegistry(Object metricRegistry)
   {
      if (metricsTrackerFactory != null) {
         throw new IllegalStateException("cannot use setMetricRegistry() and setMetricsTrackerFactory() together");
      }

      if (metricRegistry != null) {
         metricRegistry = getObjectOrPerformJndiLookup(metricRegistry);

         if (!safeIsAssignableFrom(metricRegistry, "com.codahale.metrics.MetricRegistry")
             && !(safeIsAssignableFrom(metricRegistry, "io.micrometer.core.instrument.MeterRegistry"))) {
            throw new IllegalArgumentException("Class must be instance of com.codahale.metrics.MetricRegistry or io.micrometer.core.instrument.MeterRegistry");
         }
      }

      this.metricRegistry = metricRegistry;
   }

   /**
    * Get the HealthCheckRegistry that will be used for registration of health checks by HikariCP.  Currently only
    * Codahale/DropWizard is supported for health checks.
    *
    * @return the HealthCheckRegistry instance that will be used
    */
   public Object getHealthCheckRegistry()
   {
      return healthCheckRegistry;
   }

   /**
    * Set the HealthCheckRegistry that will be used for registration of health checks by HikariCP.  Currently only
    * Codahale/DropWizard is supported for health checks.  Default is {@code null}.
    *
    * @param healthCheckRegistry the HealthCheckRegistry to be used
    */
   public void setHealthCheckRegistry(Object healthCheckRegistry)
   {
      checkIfSealed();

      if (healthCheckRegistry != null) {
         healthCheckRegistry = getObjectOrPerformJndiLookup(healthCheckRegistry);

         if (!(healthCheckRegistry instanceof HealthCheckRegistry)) {
            throw new IllegalArgumentException("Class must be an instance of com.codahale.metrics.health.HealthCheckRegistry");
         }
      }

      this.healthCheckRegistry = healthCheckRegistry;
   }

   public Properties getHealthCheckProperties()
   {
      return healthCheckProperties;
   }

   public void setHealthCheckProperties(Properties healthCheckProperties)
   {
      checkIfSealed();
      this.healthCheckProperties.putAll(healthCheckProperties);
   }

   public void addHealthCheckProperty(String key, String value)
   {
      checkIfSealed();
      healthCheckProperties.setProperty(key, value);
   }

   /**
    * This property controls the keepalive interval for a connection in the pool. An in-use connection will never be
    * tested by the keepalive thread, only when it is idle will it be tested.
    *
    * @return the interval in which connections will be tested for aliveness, thus keeping them alive by the act of checking. Value is in milliseconds, default is 0 (disabled).
    */
   public long getKeepaliveTime() {
      return keepaliveTime;
   }

   /**
    * This property controls the keepalive interval for a connection in the pool. An in-use connection will never be
    * tested by the keepalive thread, only when it is idle will it be tested.
    *
    * @param keepaliveTimeMs the interval in which connections will be tested for aliveness, thus keeping them alive by the act of checking. Value is in milliseconds, default is 0 (disabled).
    */
   public void setKeepaliveTime(long keepaliveTimeMs) {
      this.keepaliveTime = keepaliveTimeMs;
   }

   /**
    * Determine whether the Connections in the pool are in read-only mode.
    *
    * @return {@code true} if the Connections in the pool are read-only, {@code false} if not
    */
   public boolean isReadOnly()
   {
      return isReadOnly;
   }

   /**
    * Configures the Connections to be added to the pool as read-only Connections.
    *
    * @param readOnly {@code true} if the Connections in the pool are read-only, {@code false} if not
    */
   public void setReadOnly(boolean readOnly)
   {
      checkIfSealed();
      this.isReadOnly = readOnly;
   }

   /**
    * Determine whether HikariCP will self-register {@link HikariConfigMXBean} and {@link HikariPoolMXBean} instances
    * in JMX.
    *
    * @return {@code true} if HikariCP will register MXBeans, {@code false} if it will not
    */
   public boolean isRegisterMbeans()
   {
      return isRegisterMbeans;
   }

   /**
    * Configures whether HikariCP self-registers the {@link HikariConfigMXBean} and {@link HikariPoolMXBean} in JMX.
    *
    * @param register {@code true} if HikariCP should register MXBeans, {@code false} if it should not
    */
   public void setRegisterMbeans(boolean register)
   {
      checkIfSealed();
      this.isRegisterMbeans = register;
   }

   /** {@inheritDoc} */
   @Override
   public String getPoolName()
   {
      return poolName;
   }

   /**
    * Set the name of the connection pool.  This is primarily used in logging and JMX management consoles
    * to identify pools and pool configurations
    *
    * @param poolName the name of the connection pool to use
    */
   public void setPoolName(String poolName)
   {
      checkIfSealed();
      this.poolName = poolName;
   }

   /**
    * Get the ScheduledExecutorService used for housekeeping.
    *
    * @return the executor
    */
   public ScheduledExecutorService getScheduledExecutor()
   {
      return scheduledExecutor;
   }

   /**
    * Set the ScheduledExecutorService used for housekeeping.
    *
    * @param executor the ScheduledExecutorService
    */
   public void setScheduledExecutor(ScheduledExecutorService executor)
   {
      checkIfSealed();
      this.scheduledExecutor = executor;
   }

   public String getTransactionIsolation()
   {
      return transactionIsolationName;
   }

   /**
    * Get the default schema name to be set on connections.
    *
    * @return the default schema name
    */
   public String getSchema()
   {
      return schema;
   }

   /**
    * Set the default schema name to be set on connections.
    *
    * @param schema the name of the default schema
    */
   public void setSchema(String schema)
   {
      checkIfSealed();
      this.schema = schema;
   }

   /**
    * Get the user supplied SQLExceptionOverride class name.
    *
    * @return the user supplied SQLExceptionOverride class name
    * @see SQLExceptionOverride
    */
   public String getExceptionOverrideClassName()
   {
      return this.exceptionOverrideClassName;
   }

   /**
    * Set the user supplied SQLExceptionOverride class name.
    *
    * @param exceptionOverrideClassName the user supplied SQLExceptionOverride class name
    * @see SQLExceptionOverride
    */
   public void setExceptionOverrideClassName(String exceptionOverrideClassName)
   {
      checkIfSealed();

      var overrideClass = attemptFromContextLoader(exceptionOverrideClassName);
      try {
         if (overrideClass == null) {
            overrideClass = this.getClass().getClassLoader().loadClass(exceptionOverrideClassName);
            LOGGER.debug("SQLExceptionOverride class {} found in the HikariConfig class classloader {}", exceptionOverrideClassName, this.getClass().getClassLoader());
         }
      } catch (ClassNotFoundException e) {
         LOGGER.error("Failed to load SQLExceptionOverride class {} from HikariConfig class classloader {}", exceptionOverrideClassName, this.getClass().getClassLoader());
      }

      if (overrideClass == null) {
         throw new RuntimeException("Failed to load SQLExceptionOverride class " + exceptionOverrideClassName + " in either of HikariConfig class loader or Thread context classloader");
      }

      try {
         overrideClass.getConstructor().newInstance();
         this.exceptionOverrideClassName = exceptionOverrideClassName;
      }
      catch (Exception e) {
         throw new RuntimeException("Failed to instantiate class " + exceptionOverrideClassName, e);
      }
   }

   /**
    * Set the default transaction isolation level.  The specified value is the
    * constant name from the Connection class, eg.
    * TRANSACTION_REPEATABLE_READ.
    *
    * @param isolationLevel the name of the isolation level
    */
   public void setTransactionIsolation(String isolationLevel)
   {
      checkIfSealed();
      this.transactionIsolationName = isolationLevel;
   }

   /**
    * Get the thread factory used to create threads.
    *
    * @return the thread factory (may be null, in which case the default thread factory is used)
    */
   public ThreadFactory getThreadFactory()
   {
      return threadFactory;
   }

   /**
    * Set the thread factory to be used to create threads.
    *
    * @param threadFactory the thread factory (setting to null causes the default thread factory to be used)
    */
   public void setThreadFactory(ThreadFactory threadFactory)
   {
      checkIfSealed();
      this.threadFactory = threadFactory;
   }

   void seal()
   {
      this.sealed = true;
   }

   /**
    * Copies the state of {@code this} into {@code other}.
    *
    * @param other Other {@link HikariConfig} to copy the state to.
    */
   public void copyStateTo(HikariConfig other)
   {
      for (var field : HikariConfig.class.getDeclaredFields()) {
         if (!Modifier.isFinal(field.getModifiers())) {
            field.setAccessible(true);
            try {
               field.set(other, field.get(this));
            }
            catch (Exception e) {
               throw new RuntimeException("Failed to copy HikariConfig state: " + e.getMessage(), e);
            }
         }
      }

      other.sealed = false;
   }

   // ***********************************************************************
   //                          Private methods
   // ***********************************************************************

   private Class<?> attemptFromContextLoader(final String driverClassName) {
      final var threadContextClassLoader = Thread.currentThread().getContextClassLoader();
      if (threadContextClassLoader != null) {
         try {
            final var driverClass = threadContextClassLoader.loadClass(driverClassName);
            LOGGER.debug("Driver class {} found in Thread context class loader {}", driverClassName, threadContextClassLoader);
            return driverClass;
         } catch (ClassNotFoundException e) {
            LOGGER.debug("Driver class {} not found in Thread context class loader {}, trying classloader {}",
               driverClassName, threadContextClassLoader, this.getClass().getClassLoader());
         }
      }

      return null;
   }

   @SuppressWarnings("StatementWithEmptyBody")
   public void validate()
   {
      if (poolName == null) {
         poolName = generatePoolName();
      }
      else if (isRegisterMbeans && poolName.contains(":")) {
         throw new IllegalArgumentException("poolName cannot contain ':' when used with JMX");
      }

      // treat empty property as null
      //noinspection NonAtomicOperationOnVolatileField
      catalog = getNullIfEmpty(catalog);
      connectionInitSql = getNullIfEmpty(connectionInitSql);
      connectionTestQuery = getNullIfEmpty(connectionTestQuery);
      transactionIsolationName = getNullIfEmpty(transactionIsolationName);
      dataSourceClassName = getNullIfEmpty(dataSourceClassName);
      dataSourceJndiName = getNullIfEmpty(dataSourceJndiName);
      driverClassName = getNullIfEmpty(driverClassName);
      jdbcUrl = getNullIfEmpty(jdbcUrl);

      // Check Data Source Options
      if (dataSource != null) {
         if (dataSourceClassName != null) {
            LOGGER.warn("{} - using dataSource and ignoring dataSourceClassName.", poolName);
         }
      }
      else if (dataSourceClassName != null) {
         if (driverClassName != null) {
            LOGGER.error("{} - cannot use driverClassName and dataSourceClassName together.", poolName);
            // NOTE: This exception text is referenced by a Spring Boot FailureAnalyzer, it should not be
            // changed without first notifying the Spring Boot developers.
            throw new IllegalStateException("cannot use driverClassName and dataSourceClassName together.");
         }
         else if (jdbcUrl != null) {
            LOGGER.warn("{} - using dataSourceClassName and ignoring jdbcUrl.", poolName);
         }
      }
      else if (jdbcUrl != null || dataSourceJndiName != null) {
         // ok
      }
      else if (driverClassName != null) {
         LOGGER.error("{} - jdbcUrl is required with driverClassName.", poolName);
         throw new IllegalArgumentException("jdbcUrl is required with driverClassName.");
      }
      else {
         LOGGER.error("{} - dataSource or dataSourceClassName or jdbcUrl is required.", poolName);
         throw new IllegalArgumentException("dataSource or dataSourceClassName or jdbcUrl is required.");
      }

      validateNumerics();

      if (LOGGER.isDebugEnabled() || unitTest) {
         logConfiguration();
      }
   }

   private void validateNumerics()
   {
      if (maxLifetime != 0 && maxLifetime < SECONDS.toMillis(30)) {
         LOGGER.warn("{} - maxLifetime is less than 30000ms, setting to default {}ms.", poolName, MAX_LIFETIME);
         maxLifetime = MAX_LIFETIME;
      }

      // keepalive time must larger then 30 seconds
      if (keepaliveTime != 0 && keepaliveTime < SECONDS.toMillis(30)) {
         LOGGER.warn("{} - keepaliveTime is less than 30000ms, disabling it.", poolName);
         keepaliveTime = DEFAULT_KEEPALIVE_TIME;
      }

      // keepalive time must be less than maxLifetime (if maxLifetime is enabled)
      if (keepaliveTime != 0 && maxLifetime != 0 && keepaliveTime >= maxLifetime) {
         LOGGER.warn("{} - keepaliveTime is greater than or equal to maxLifetime, disabling it.", poolName);
         keepaliveTime = DEFAULT_KEEPALIVE_TIME;
      }

      if (leakDetectionThreshold > 0 && !unitTest) {
         if (leakDetectionThreshold < SECONDS.toMillis(2) || (leakDetectionThreshold > maxLifetime && maxLifetime > 0)) {
            LOGGER.warn("{} - leakDetectionThreshold is less than 2000ms or more than maxLifetime, disabling it.", poolName);
            leakDetectionThreshold = 0;
         }
      }

      if (connectionTimeout < SOFT_TIMEOUT_FLOOR) {
         LOGGER.warn("{} - connectionTimeout is less than {}ms, setting to {}ms.", poolName, SOFT_TIMEOUT_FLOOR, CONNECTION_TIMEOUT);
         connectionTimeout = CONNECTION_TIMEOUT;
      }

      if (validationTimeout < SOFT_TIMEOUT_FLOOR) {
         LOGGER.warn("{} - validationTimeout is less than {}ms, setting to {}ms.", poolName, SOFT_TIMEOUT_FLOOR, VALIDATION_TIMEOUT);
         validationTimeout = VALIDATION_TIMEOUT;
      }

      if (maxPoolSize < 1) {
         maxPoolSize = DEFAULT_POOL_SIZE;
      }

      if (minIdle < 0 || minIdle > maxPoolSize) {
         minIdle = maxPoolSize;
      }

      if (idleTimeout + SECONDS.toMillis(1) > maxLifetime && maxLifetime > 0 && minIdle < maxPoolSize) {
         LOGGER.warn("{} - idleTimeout is close to or more than maxLifetime, disabling it.", poolName);
         idleTimeout = 0;
      }
      else if (idleTimeout != 0 && idleTimeout < SECONDS.toMillis(10) && minIdle < maxPoolSize) {
         LOGGER.warn("{} - idleTimeout is less than 10000ms, setting to default {}ms.", poolName, IDLE_TIMEOUT);
         idleTimeout = IDLE_TIMEOUT;
      }
      else  if (idleTimeout != IDLE_TIMEOUT && idleTimeout != 0 && minIdle == maxPoolSize) {
         LOGGER.warn("{} - idleTimeout has been set but has no effect because the pool is operating as a fixed size pool.", poolName);
      }
   }

   private void checkIfSealed()
   {
      if (sealed) throw new IllegalStateException("The configuration of the pool is sealed once started. Use HikariConfigMXBean for runtime changes.");
   }

   private void logConfiguration()
   {
      LOGGER.debug("{} - configuration:", poolName);
      final var propertyNames = new TreeSet<>(PropertyElf.getPropertyNames(HikariConfig.class));
      for (var prop : propertyNames) {
         try {
            var value = PropertyElf.getProperty(prop, this);
            if ("dataSourceProperties".equals(prop)) {
               var dsProps = PropertyElf.copyProperties(dataSourceProperties);
               dsProps.setProperty("password", "");
               value = dsProps;
            }

            if ("initializationFailTimeout".equals(prop) && initializationFailTimeout == Long.MAX_VALUE) {
               value = "infinite";
            }
            else if ("transactionIsolation".equals(prop) && transactionIsolationName == null) {
               value = "default";
            }
            else if (prop.matches("scheduledExecutorService|threadFactory") && value == null) {
               value = "internal";
            }
            else if (prop.contains("jdbcUrl") && value instanceof String) {
               value = ((String)value).replaceAll("([?&;][^&#;=]*[pP]assword=)[^&#;]*", "$1");
            }
            else if (prop.contains("password")) {
               value = "";
            }
            else if (value instanceof String) {
               value = "\"" + value + "\""; // quote to see lead/trailing spaces is any
            }
            else if (value == null) {
               value = "none";
            }
            LOGGER.debug("{}{}", (prop + "................................................").substring(0, 32), value);
         }
         catch (Exception e) {
            // continue
         }
      }
   }

   private void loadProperties(String propertyFileName)
   {
      final var propFile = new File(propertyFileName);
      try (final var is = propFile.isFile() ? new FileInputStream(propFile) : this.getClass().getResourceAsStream(propertyFileName)) {
         if (is != null) {
            var props = new Properties();
            props.load(is);
            PropertyElf.setTargetFromProperties(this, props);
         }
         else {
            throw new IllegalArgumentException("Cannot find property file: " + propertyFileName);
         }
      }
      catch (IOException io) {
         throw new RuntimeException("Failed to read property file", io);
      }
   }

   private String generatePoolName()
   {
      final var prefix = "HikariPool-";
      try {
         // Pool number is global to the VM to avoid overlapping pool numbers in classloader scoped environments
         synchronized (System.getProperties()) {
            final var next = String.valueOf(Integer.getInteger("com.zaxxer.hikari.pool_number", 0) + 1);
            System.setProperty("com.zaxxer.hikari.pool_number", next);
            return prefix + next;
         }
      } catch (AccessControlException e) {
         // The SecurityManager didn't allow us to read/write system properties
         // so just generate a random pool number instead
         final var random = ThreadLocalRandom.current();
         final var buf = new StringBuilder(prefix);

         for (var i = 0; i < 4; i++) {
            buf.append(ID_CHARACTERS[random.nextInt(62)]);
         }

         LOGGER.info("assigned random pool name '{}' (security manager prevented access to system properties)", buf);

         return buf.toString();
      }
   }

   private Object getObjectOrPerformJndiLookup(Object object)
   {
      if (object instanceof String) {
         try {
            var initCtx = new InitialContext();
            return initCtx.lookup((String) object);
         }
         catch (NamingException e) {
            throw new IllegalArgumentException(e);
         }
      }
      return object;
   }
}

from this code, the maxLifeTime has been updated to 30000ms at least in this version.

So now please update your HikariCP version to the latest version 2.7.4 if you want to set maxLifeTime to 30000ms.

But if you update your HikariCP version to 2.7.4 with JDK 8, i also recommend you two points:

1. to set maxLifeTime value to be at least 30000ms.

2. to set maxLifeTime value few minute less than mysql’s wait_timeout(show variables like “%timeout%”) to avoid broken connection exception.

if you want to get more detail. please refer to my answer in the stackoverflow:

https://stackoverflow.com/questions/28180562/hikaricp-and-maxlifetime/47694402#47694402

如果有问题可以私信我