MySQL數據庫連接下降到JBoss應用程序

Question

我正在帶有MySQL 5.1數據存儲的JBoss 7服務器上運行Java Web應用程序。 我使用JDBC與數據庫通信。 有一種特定的方法需要大量數據庫查詢。 當我運行一次或兩次時，它運行良好，但是運行了5次（即使相距5倍）后，我失去了數據庫連接，並導致以下錯誤：

WARN  [org.jboss.jca.core.connectionmanager.pool.strategy.OnePool] (http-localhost-127.0.0.1-9091-3) IJ000604: Throwable while attempting to get a new connection: null: javax.resource.ResourceException: Could not create connection
    at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.getLocalManagedConnection(LocalManagedConnectionFactory.java:277)
    at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.createManagedConnection(LocalManagedConnectionFactory.java:235)
    at org.jboss.jca.core.connectionmanager.pool.mcp.SemaphoreArrayListManagedConnectionPool.createConnectionEventListener(SemaphoreArrayListManagedConnectionPool.java:706)
    at org.jboss.jca.core.connectionmanager.pool.mcp.SemaphoreArrayListManagedConnectionPool.getConnection(SemaphoreArrayListManagedConnectionPool.java:321)
    at org.jboss.jca.core.connectionmanager.pool.AbstractPool.getSimpleConnection(AbstractPool.java:392)
    at org.jboss.jca.core.connectionmanager.pool.AbstractPool.getConnection(AbstractPool.java:357)
    at org.jboss.jca.core.connectionmanager.AbstractConnectionManager.getManagedConnection(AbstractConnectionManager.java:351)
    at org.jboss.jca.core.connectionmanager.AbstractConnectionManager.getManagedConnection(AbstractConnectionManager.java:326)
    at org.jboss.jca.core.connectionmanager.AbstractConnectionManager.allocateConnection(AbstractConnectionManager.java:467)
    at org.jboss.jca.adapters.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:129)
    ...
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) [:1.7.0_45]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) [:1.7.0_45]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) [:1.7.0_45]
    at java.lang.reflect.Constructor.newInstance(Unknown Source) [:1.7.0_45]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1128)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2336)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.GeneratedConstructorAccessor9.newInstance(Unknown Source) [:1.7.0_45]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) [:1.7.0_45]
    at java.lang.reflect.Constructor.newInstance(Unknown Source) [:1.7.0_45]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
    at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.getLocalManagedConnection(LocalManagedConnectionFactory.java:249)
    ... 86 more

我對此問題進行了一些搜索，我懷疑我沒有在某處正確關閉連接。 我注釋掉了所有進行數據庫調用的方法，直到發現似乎引起問題的方法為止。 它有幾個PreparedStatement在循環內運行，但是我可以肯定地說，我已經在每個最終關閉的打開的PreparedStatements和ResultSet的try-finally中捕獲了每個調用。 這是有問題的方法：

private List<SupplierDisclosureDto> getSupplierDisclosureListInClientDB(UserDto user, List<SupplierDto> coreSuppliers) throws SQLException{
    List<SupplierDisclosureDto> sdList = new ArrayList<SupplierDisclosureDto>();
    Connection connection = user.getConnection();

    PreparedStatement psAllFragrances = null;
    ResultSet rsAllFragrances = null;
    PreparedStatement psFormulations = null;
    ResultSet rsFormulations = null;
    PreparedStatement psIfra = null;
    ResultSet rsIfra = null;
    PreparedStatement psDocuments = null;
    ResultSet rsDocuments = null;

    try{

        //find all fragrances and its corresponding values
        psAllFragrances = connection.prepareStatement(
            "SELECT " +
                "c.child_trade_name AS tradeName, c.child_supplier_name AS supplier, r.raw_material_number AS rmNo, " +
                "r.id AS rid, d.id AS did, o.supplier_id AS contentRole, o.id AS oid, s.short_name AS supplierShortname " +
            "FROM object o " +
                "left join composition c on c.id = (SELECT cx.id FROM composition AS cx WHERE cx.child_object_id = o.id LIMIT 1) " +
                "left join raw_material r on r.id = (SELECT rx.id FROM raw_material AS rx WHERE rx.object_id = o.id LIMIT 1) " +
                "left join document_status d on d.id = (SELECT dx.id FROM document_status AS dx WHERE dx.raw_material_id = r.id LIMIT 1) " +
                "left join supplier s on s.id = o.supplier_id " +
            "WHERE o.type<>0 AND r.is_fragrance=1");
        rsAllFragrances = psAllFragrances.executeQuery();
        while(rsAllFragrances.next()){
            SupplierDisclosureDto sd = new SupplierDisclosureDto();
            sd.setContentRole(rsAllFragrances.getInt("contentRole"));

            List<FormulaDto> formulas = new ArrayList<FormulaDto>();

            try{
                psFormulations = connection.prepareStatement(
                    "SELECT " +
                        "c.child_supplier_name AS supplier, c.child_overall_percent , ca.category , s.subcategory , p.brand , p.sub_brand , p.notebook_number , " +
                        "fo.status AS fStatus , f.unique_id, f.name , f.formula_number , f.version , f.date_modified_provided , f.id AS fid " +
                    "FROM composition c " +
                        "left join formula f on f.id = (SELECT fx.id FROM formula AS fx WHERE fx.object_id = c.parent_object_id LIMIT 1) " +
                        "left join object fo on fo.id = (SELECT fox.id FROM object AS fox WHERE fox.id = c.parent_object_id LIMIT 1) " +
                        "left join product p on p.id = (SELECT px.id FROM product AS px WHERE px.id = f.product_id LIMIT 1) " +
                        "left join subcategory s on s.id = (SELECT sx.id FROM subcategory AS sx WHERE sx.id = p.subcategory_id LIMIT 1) " +
                        "left join category ca on ca.id = (SELECT cax.id FROM category AS cax WHERE cax.id = s.category_id LIMIT 1) " +
                    "WHERE c.child_object_id=?");
                psFormulations.setInt(1, sd.getParentObjectId());
                rsFormulations = psFormulations.executeQuery();
                while(rsFormulations.next()){

                    CategoryDto category = new CategoryDto();
                    category.setCategory(rsFormulations.getString("category"));

                    SubcategoryDto subcategory = new SubcategoryDto();
                    subcategory.setSubcategory(rsFormulations.getString("subcategory"));
                    subcategory.setCategory(category);

                    ProductDto product = new ProductDto();
                    product.setBrand(rsFormulations.getString("brand"));
                    product.setSubcategory(subcategory);

                    ObjectDto formulaObject = new ObjectDto();
                    formulaObject.setStatus(rsFormulations.getString("fStatus"));

                    FormulaDto formula = new FormulaDto();
                    formula.setFormulaNumber(rsFormulations.getString("formula_number"));
                    formula.setObject(formulaObject);
                    formula.setProduct(product);

                    try{
                        psIfra = connection.prepareStatement("SELECT i.category FROM ifra_category i WHERE i.formula_id = ?");
                        psIfra.setInt(1, rsFormulations.getInt("fid"));
                        rsIfra = psIfra.executeQuery();
                        List<String> ifraCategories = new ArrayList<String>();
                        while(rsIfra.next()){
                            ifraCategories.add(rsIfra.getString("category"));
                        }
                        rsIfra.close();
                        psIfra.close();
                        formula.setIfraCategories(ifraCategories.toArray(new String[ifraCategories.size()]));
                    }finally{
                        if(rsIfra!=null)
                            rsIfra.close();
                        if(psIfra!=null)
                            psIfra.close();
                    }

                    formulas.add(formula);
                }
                rsFormulations.close();
                psFormulations.close();
            }finally{
                if(rsFormulations!=null)
                    rsFormulations.close();
                if(psFormulations!=null)
                    psFormulations.close();
            }

            sd.setFormulas(formulas);

            try{
                psDocuments = connection.prepareStatement(
                    "SELECT " +
                        "d.id AS d_id, d.document_status_id, d.document_type, d.is_active AS d_is_active, d.uploaded_by, " +
                        "d.last_uploaded, d.previous_version_id, d.extension, d.filename, u.id AS u_id, u.user_name, u.email, u.role_id, " +
                        "u.content_role_id, u.client_id, u.name, u.address, u.company, u.phone_number, u.fax_number, c.short_name " +
                    "FROM document_status_detail d " +
                        "left join irw.user u on u.id = (SELECT ux.id FROM irw.user AS ux WHERE ux.id = d.uploaded_by LIMIT 1) " +
                        "left join irw.client c on c.id = (SELECT cx.id FROM irw.client AS cx WHERE cx.id = u.client_id LIMIT 1) " +
                    "WHERE d.document_status_id = ? " +
                    "ORDER BY document_type, last_uploaded ASC");
                psDocuments.setInt(1, rsAllFragrances.getInt("did"));
                rsDocuments = psDocuments.executeQuery();
                SupplierDocumentDto previousDocument = null;
                HashMap<String, SupplierDocumentDto> documents = new HashMap<String, SupplierDocumentDto>();
                while(rsDocuments.next()){
                    SupplierDocumentDto currentDocument = new SupplierDocumentDto();
                    currentDocument.setIsActive((rsDocuments.getInt("d_is_active")==0)?false:true);

                    UserDto userDto = new UserDto();
                    userDto.setId(rsDocuments.getInt("u_id"));
                    currentDocument.setUploadedByUser(userDto);

                    if(previousDocument!=null && previousDocument.getType().equalsIgnoreCase(currentDocument.getType())){
                        currentDocument.setPreviousVersion(previousDocument);
                    }

                    documents.put(currentDocument.getType(), currentDocument);

                    previousDocument = currentDocument;
                }
                rsDocuments.close();
                psDocuments.close();

                sd.setDocuments(documents);
                sdList.add(sd);
            }finally{
                if(rsDocuments!=null)
                    rsDocuments.close();
                if(psDocuments!=null)
                    psDocuments.close();
            }

        }
        rsAllFragrances.close();
        psAllFragrances.close();
    }finally{
        if(rsAllFragrances!=null)
            rsAllFragrances.close();
        if(psAllFragrances!=null)
            psAllFragrances.close();
    }
    return sdList;
}

由於可以為不同的用戶分配不同的數據庫，因此用戶登錄時將初始化與數據庫的連接。 如果有幫助，這是standalone.xml中我的數據存儲的配置（每個數據庫都相同）：

<datasource jndi-name="java:jboss/datasources/DATABASEDS" pool-name="DATABASEDS-Pool" enabled="true" jta="false" use-java-context="true" use-ccm="true">
    <connection-url>
        jdbc:mysql://localhost:3306/DATABASE?zeroDateTimeBehavior=convertToNull
    </connection-url>
    <driver>
        mysql-connector-java-5.1.18-bin.jar
    </driver>
    <transaction-isolation>
        TRANSACTION_READ_COMMITTED
    </transaction-isolation>
    <pool>
        <min-pool-size>
            10
        </min-pool-size>
        <max-pool-size>
            500
        </max-pool-size>
        <prefill>
            true
        </prefill>
        <use-strict-min>
            false
        </use-strict-min>
        <flush-strategy>
            FailingConnectionOnly
        </flush-strategy>
    </pool>
    <security>
        <user-name>
            USERNAME
        </user-name>
        <password>
            PASSWORD
        </password>
    </security>
    <validation>
        <check-valid-connection-sql>
            SELECT 1
        </check-valid-connection-sql>
        <validate-on-match>
            false
        </validate-on-match>
        <background-validation>
            false
        </background-validation>
        <use-fast-fail>
            false
        </use-fast-fail>
    </validation>
    <timeout>
        <blocking-timeout-millis>
            60000
        </blocking-timeout-millis>
        <idle-timeout-minutes>
            1
        </idle-timeout-minutes>
    </timeout>
    <statement>
        <track-statements>
            TRUE
        </track-statements>
        <prepared-statement-cache-size>
            0
        </prepared-statement-cache-size>
        <share-prepared-statements/>
    </statement>
</datasource>

我不確定是什么引起了該問題，並且我嘗試了很多解決方案。 任何幫助將非常感激！

解決了：

我通過一些調試發現了泄漏。 事實證明，是通過另一種方法繼續打開新連接，但從未關閉它們。 我進行了最后嘗試，以確保在使用完新連接后立即將其關閉。

Answer 1

嘗試在應用程序啟動中使用連接池，或在jboss中配置它，例如：

 ComboPooledDataSource connectionPoolDatasource = new ComboPooledDataSource();
  connectionPoolDatasource.setDriverClass("com.mysql.jdbc.Driver");
  connectionPoolDatasource.setJdbcUrl("jdbc:mysql://localhost:3306/mydatabase");
  connectionPoolDatasource.setUser("root");
  connectionPoolDatasource.setPassword("");
  connectionPoolDatasource.setMinPoolSize(1);
  connectionPoolDatasource.setAcquireIncrement(5);
  connectionPoolDatasource.setMaxPoolSize(20);
  Connection con = connectionPoolDatasource.getConnection();

您也可以在jboss中進行配置，請參考此鏈接。

Answer 2

您可以在下面嘗試

在<subsystem xmlns="urn:jboss:domain:jca:1.1">添加<cached-connection-manager debug="true"/> <subsystem xmlns="urn:jboss:domain:jca:1.1">

JBoss將關閉泄漏的連接

啟用JCA日志記錄后，您需要通過檢查日志來查找泄漏的連接。 我這樣解決了連接泄漏。

<logger category="org.jboss.jca">
                <level name="DEBUG"/>
</logger>

您將在日志中獲得以下條目

DEBUG [org.jboss.jca.core.connectionmanager.pool.strategy.OnePool] (MSC service thread 1-4) {JNDI_NAME}: getConnection(null, null) [1/100] ->這意味着從池中獲取連接。

DEBUG [org.jboss.jca.core.connectionmanager.pool.strategy.OnePool] (MSC service thread 1-4) {JNDI_NAME}: returnConnection(607e334, false) [1/99] ->表示將連接返回到池

您可以檢查哪個查詢沒有向池返回連接，並從執行該查詢的位置檢查您的應用程序。 修理它。