你好！
我是用的是flink 1.11.2版本，在MySQL的驱动包中有一下的代码：
/*
Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
The MySQL Connector/J is licensed under the terms of the GPLv2
<
http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most MySQL Connectors.
There are special exceptions to the terms and conditions of the GPLv2 as it is applied to
this software, see the FOSS License Exception
<
http://www.mysql.com/about/legal/licensing/foss-exception.html>.
This program is free software; you can redistribute it and/or modify it under the terms
of the GNU General Public License as published by the Free Software Foundation; version 2
of the License.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this
program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth
Floor, Boston, MA 02110-1301 USA
*/
package com.mysql.cj.jdbc;
import java.lang.ref.Reference;
import com.mysql.cj.jdbc.NonRegisteringDriver.ConnectionPhantomReference;
public class AbandonedConnectionCleanupThread extends Thread {
private static boolean running = true;
private static Thread threadRef = null;
public AbandonedConnectionCleanupThread() {
super("Abandoned connection cleanup thread");
}
@Override
public void run() {
threadRef = this;
while (running) {
try {
Reference<? extends ConnectionImpl> ref = NonRegisteringDriver.refQueue.remove(100);
if (ref != null) {
try {
((ConnectionPhantomReference) ref).cleanup();
} finally {
NonRegisteringDriver.connectionPhantomRefs.remove(ref);
}
}
} catch (Exception ex) {
// no where to really log this if we're static
}
}
}
public static void shutdown() throws InterruptedException {
running = false;
if (threadRef != null) {
threadRef.interrupt();
threadRef.join();
threadRef = null;
}
}
}
而上面的shutdown没有被调用，导致有线程停止不了，造成OutOfMemoryError: Metaspace.
------------------ 原始邮件 ------------------
发件人: "user-zh" <
[hidden email]>;
发送时间: 2020年11月4日(星期三) 晚上9:32
收件人: "user-zh"<
[hidden email]>;
主题: Re:1.11.1 报OutOfMemoryError: Metaspace. 错误
Hi Asahi,
你用的 Flink 版本是哪个呢？
对于 Metaspace OOM 的话，如果是稳定在某些值，确实需要加大这个内存大小的话，可以设置 参数 `taskmanager-memory-jvm-metaspace-size` [1]。
对于根本原因的话，需要看下为什么有那么多的无效 Conection，是不是长时间没有数据发送导致 connection invalid，然后再次使用时候就会重启，导致进程级别的缓存无效 Connection对象，这样的话，有线程一直在检测这个对象，就无法 GC。对于 connection 是否 invalid 的处理目前有个 issue[2] 已经解决了。
[1]
https://ci.apache.org/projects/flink/flink-docs-release-1.11/ops/config.html#taskmanager-memory-jvm-metaspace-size[2]
https://issues.apache.org/jira/browse/FLINK-16681Best,
Hailong Wang
在 2020-11-04 19:08:37，"Asahi Lee" <
[hidden email]> 写道：
>你好！
>&nbsp; &nbsp; &nbsp; 我是用flink sql,通过JDBC源读取mysql表数据，多次提交后，报OutOfMemoryError: Metaspace.错误，最后分析是mysql驱动包中有个守护线程一直在检测清理失效的connection，导致有线程一直存在，class资源无法释放导致的，请问这个如何处理？
Locked
