Webサービスの呼び出しごとに最大接続数を維持しています。 EntityManagerが毎回作成され、データベースへの新しい接続を作成しているように見えますが、接続を完全に閉じたり解放したりすることはありません。私は常に私の接続を最大限に使い、私は最初の呼び出しの後に再び接続したり質問を実行することはできません。Hibernate JPAが多すぎる接続
EntityManagerではなくSessionManager/SessionFactoryなどを使用する必要がありますか?
私も静的Connection cconn
を使用せず、EntityManager
との接続を維持してから、最後のブロックでemを閉じますが、まだエラーが表示されます。私はJPAの初心者ですので、私のデザイン、設定、コード、すべてですか?接続を取得
- ConnectionUtil.java
public static Connection cconn = null;
public static Connection conn(){
try {
if(ConnectionUtil.cconn != null && !ConnectionUtil.cconn.isClosed()){
return cconn;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Connection conn = null;
try {
String lcp = ConnectionUtil.getLcp();
logging.info("LCP : " + lcp);
EntityManagerFactory factory = null;
Map<String,Object> prop = null;
String url ,password, user, connString;
// Set default Connection details
if(lcp == null){
factory = Persistence.createEntityManagerFactory(LOCAL_PER);
prop = factory.getProperties();
url = (String) prop.get("javax.persistence.jdbc.url");
password = (String) prop.get("javax.persistence.jdbc.password");
user = (String) prop.get("javax.persistence.jdbc.user");
connString = url +"?user="+user+"&password="+password;
connString = "jdbc:mysql://localhost:3306/"+ConnectionUtil.DATABASE+"?" + "user=root&password=password";
logging.info("Setting EntityManager to: default values");
logging.info("Using string: "+ connString);
Properties properties = new Properties();
properties.put("connectTimeout", "20000");
conn = DriverManager.getConnection(connString,properties);
cconn = conn;
}
persistance.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="Hunting" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/database"/>
<property name="javax.persistence.jdbc.user" value="root"/>
<property name="javax.persistence.jdbc.password" value="password"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<!-- Hibernate properties -->
<property name="hibernate.show_sql" value="false" />
<property name="hibernate.format_sql" value="false" />
<property name="hibernate.connection.release_mode" value="on_close" />
<property name="hibernate.connection.pool_size" value="100" />
<!-- Configuring Connection Pool -->
<property name="hibernate.c3p0.min_size" value="5" />
<property name="hibernate.c3p0.max_size" value="20" />
<property name="hibernate.c3p0.timeout" value="20" />
<property name="hibernate.c3p0.max_statements" value="50" />
<property name="hibernate.c3p0.idle_test_period" value="2000" />
</properties>
</persistence-unit>
私のWebサービス内の関数からクラブのユーザーを取得します。
public static Club getClubById(long id){
Club cc = new Club();
EntityManager em = null;
try{
em = ConnectionUtil.getEnitityManager();
cc = em.find(Club.class, id);
cc.buildClubUsers();
}finally{
if(em != null){
em.close();
}
}
return cc;
}
接続エラー
15:32:26.315 [http-bio-8080-exec-7] WARN org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator - HHH000022: c3p0 properties were encountered, but the org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider provider class was not found on the classpath; these properties are going to be ignored.
15:32:26.315 [http-bio-8080-exec-7] INFO org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl - HHH000402: Using Hibernate built-in connection pool (not for production use!)
15:32:26.315 [http-bio-8080-exec-7] INFO org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl - HHH000115: Hibernate connection pool size: 100
15:32:26.315 [http-bio-8080-exec-7] INFO org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl - HHH000006: Autocommit mode: true
15:32:26.315 [http-bio-8080-exec-7] INFO org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl - HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/database]
15:32:26.315 [http-bio-8080-exec-7] INFO org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl - HHH000046: Connection properties: {user=root, password=password, autocommit=true, release_mode=on_close}
15:32:26.315 [http-bio-8080-exec-7] DEBUG org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl - Opening new JDBC connection
15:32:26.316 [http-bio-8080-exec-7] WARN org.hibernate.engine.jdbc.internal.JdbcServicesImpl - HHH000342: Could not obtain connection to query metadata : Data source rejected establishment of connection, message from server: "Too many connections"
編集:1つのを追加しましたC3POと同じ "あまりにも多くの接続" エラーを得た
Mar 05, 2017 3:46:17 PM com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask run
WARNING: [email protected]9 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too many connections"
あなたは本当に各ビジネス/リポジトリユースケースで新しい 'EntityManagerFactory'を作成すべきではありません。それはあなたのアプリケーションが何の理由もありませんオーバーヘッドのかなりの量になります。通常、アプリケーションは起動時に 'EntityManagerFactory'または' SessionFactory'を生成し、ユースケースに必要に応じてそれぞれ 'EntityManager'インスタンスまたは' Session'インスタンスを作成するためにファクトリを再利用する必要があります。 – Naros