java - Play Framework : DB Connection Pool Shut Down

Question

我有一个使用 HikariCP jdbc 连接池运行的 Play 应用程序。

该应用程序将正常运行一段时间，但短时间后它将关闭连接池，这意味着我无法再使用该应用程序。

SBT 构建:

name := "virtual-betting"
version := "1.0"

lazy val root = (project in file(".")).enablePlugins(PlayJava).settings(javacOptions ++= Seq("-source", "1.8", "-target", "1.8"))

scalaVersion := "2.11.8"

libraryDependencies ++= Seq(
  javaJdbc,
  javaJpa,
  javaJpa.exclude("org.hibernate.javax.persistence", "hibernate-jpa-2.1-api"),
  "org.hibernate" % "hibernate-core" % "5.1.0.Final",
  "org.hibernate" % "hibernate-entitymanager" % "5.1.0.Final",
  "com.typesafe.play" % "play-java-jpa_2.11" % "2.5.3",
  "org.springframework" % "spring-context" % "4.2.4.RELEASE",
  "org.webjars" % "bootstrap" % "3.3.4",
  "mysql" % "mysql-connector-java" % "5.1.42",
  cache,
  javaWs,
  "org.jsoup" % "jsoup" % "1.7.2",
  "org.apache.commons" % "commons-email" % "1.4",
  "org.apache.cxf" % "cxf-rt-rs-client" % "3.1.6",
  "com.google.code.gson" % "gson" % "2.7",
  "com.squareup.okhttp3" % "okhttp" % "3.4.1"
)

fork in run := false


fork in run := true

应用程序.conf:

## Database Connection Pool
# https://www.playframework.com/documentation/latest/SettingsJDBC
# ~~~~~
# Play doesn't require a JDBC database to run, but you can easily enable one.
#
# libraryDependencies += jdbc
#

play.db {
  # The combination of these two settings results in "db.default" as the
  # default JDBC pool:
  config = "db"
  default = "default"

  pool = "hikaricp"
  # Play uses HikariCP as the default connection pool.  You can override
  # settings by changing the prototype:

  prototype {
    pool = "hikaricp"

    # Sets a fixed JDBC connection pool size of 50
    hikaricp.minimumIdle = 0
    hikaricp.maximumPoolSize = 30
    hikaricp.connectionTimeout = 30000
    hikaricp.idleTimeout = 600000
    hikaricp.maxLifetime = 1800000
    hikaricp.leakDetectionThreshold = 5000
    hikaricp.connectionTestQuery = "SELECT 1"
    hikaricp.readOnly = false

    hikari.dataSourceClassName = com.mysql.jdbc.jdbc2.optional.MysqlDataSource
    # The database url
    #url = "jdbc:mysql://localhost:3306/madduxsp_sportsbook?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8"

    registerMBeans = true
    poolName = "sportsbook_pool"
  }
}

db.default.driver=com.mysql.jdbc.Driver
db.default.url="jdbc:mysql://localhost:3306/madduxsp_sportsbook_new?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8"
db.default.username=root
db.default.password=mypassword
db.default.jndiName=DefaultDS
jpa.default=defaultPersistenceUnit

application.secret="mysecret"

spring.context.location=application-context.xml

我编写了一些代码来保持数据库连接处于 Activity 状态，万一它因不活动而关闭，这可以工作。

我的 DbKeepAliveService:

package services;

import play.Logger;
import play.db.jpa.JPAApi;
import util.DbKeepAliveTask;

import javax.inject.Inject;
import javax.inject.Singleton;
import java.util.Timer;

@Singleton
public class DbKeepAliveService {

    private final JPAApi jpa;

    @Inject
    public DbKeepAliveService(JPAApi jpa) {
        this.jpa = jpa;

        DbKeepAliveTask dbKeepAliveTask = new DbKeepAliveTask(jpa);
        Logger.info("Application has started");

        Timer timer = new Timer("dbKeepAlive", true);
        timer.schedule(dbKeepAliveTask, 0, 1200000);
    }
}

但这不起作用。这是我的日志:

2017-05-06 06:12:15,010 [INFO] from application in dbKeepAlive - Keeping database connection alive...
2017-05-06 06:32:15,010 [INFO] from application in dbKeepAlive - Keeping database connection alive...
2017-05-06 06:52:15,010 [INFO] from application in dbKeepAlive - Keeping database connection alive...
2017-05-06 06:58:35,894 [INFO] from application in Thread-8 - Application shutdown...
2017-05-06 06:58:36,054 [INFO] from application in Thread-8 - Shutting down connection pool.

有谁知道为什么它可能会不断关闭数据库连接池？我怀疑这与我的配置有关，但老实说我不能确定。

我还了解到这可能与不在生产模式下运行应用程序有关，但我已经设置了 secret 。

我使用以下命令运行应用程序:

./bin/virtual-betting -Dconfig.file=conf/production.conf -Dplay.crypto.secret="mysecret" &

在 conf/development.conf 文件中设置 play.crypto.secret 属性。

我已经关注这个问题很长时间了，非常感谢您的帮助!

Answer 1

从您提供的日志来看，数据库连接池关闭的原因是应用程序(play)关闭了。

如 Play documentation 中所述:

When you run the start command, Play forks a new JVM and runs the default Netty HTTP server. The standard output stream is redirected to the Play console, so you can monitor its status.

The server's process id is displayed at bootstrap and written to the RUNNING_PID file. To kill a running Play server, it is enough to send a SIGTERM to the process to properly shutdown the application.

If you type Ctrl+D, the Play console will quit, but the created server process will continue running in background. The forked JVM’s standard output stream is then closed, and logging can be read from the logs/application.log file.

因此，进程可能已收到 SIGTERM 信号，Play 应用程序是使用 play run 而不是 play start 启动的，并且有人使用了 Ctrl+控制台上的 D 或者服务器可能正在终止该进程，因为它的内存不足，这可能表明也可能不表明您的应用程序中存在内存泄漏，请参阅 OOM killer :

Under desperately low memory conditions, the out-of-memory (OOM) killer kicks in and picks a process to kill using a set of heuristics which has evolved over time.

我建议您分析您的应用程序/监视服务器内存(您还可以检查服务器日志以查看内核是否杀死了任何进程)。

如果您能够延长HikariCPModule并覆盖 close 方法，您可以添加一个记录器调用来打印当前线程堆栈跟踪并验证实际调用 close 的内容，例如。关闭 Hook 或其他东西。

  override def close(dataSource: DataSource) = {
    Logger.info("Shutting down connection pool.")
    Thread.dumpStack()
    dataSource match {
      case ds: HikariDataSource => ds.close()
      case _ => sys.error("Unable to close data source: not a HikariDataSource")
    }

为“com.zaxxer.hikari”和 Play 启用调试日志记录可能有助于进一步诊断数据库设置/应用程序的问题。

祝你好运!