mysql - liquibase 无法更新数据库和/或非常慢

Question

当我们使用 Liquibase 执行以下变更集时，我们遇到一个非常奇怪的问题:

<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.3.xsd">

    <changeSet id="add companyinfo.identifier" author="domi">
        <addColumn tableName="companyinfo">
            <column name="identifier" type="VARCHAR(50)" />
        </addColumn>
    </changeSet>

    <changeSet id="add uk companyinfo.identifier" author="domi">
        <addUniqueConstraint    columnNames="identifier" 
                                tableName="companyinfo" 
                                constraintName="uk_companyinfo_identifier"/>
    </changeSet>

</databaseChangeLog>

变更集将新列 (identifier) 添加到表 companyinfo 中，并在同一列上定义唯一约束。该表大约有 1'500'000 条记录。

这些变更集是通过 Jenkins 管道脚本触发的 org.liquibase:liquibase-maven-plugin:3.5.3:update maven 插件/目标针对 MySQL(版本 5.5.54)执行的。 (Jenkins和DB位于美国东海岸)。我们使用的 JDBC 驱动程序是:mysql:mysql-connector-java:5.1.41

通常我们的 liquibase 不会有任何问题，但是当我们运行这个变更集时，我们总是在 2 小时后收到如下错误:

[INFO] --- liquibase-maven-plugin:3.5.3:update (default) @ persistence ---
[INFO] ------------------------------------------------------------------------
[INFO] Executing on Database: jdbc:mysql://yyyy.xxxx.net:3306/my_db?characterEncoding=utf8
INFO 5/2/17 5:11 PM: liquibase: Successfully acquired change log lock
INFO 5/2/17 5:11 PM: liquibase: Reading from DATABASECHANGELOG
SEVERE 5/2/17 7:11 PM: liquibase: src/main/resources/db/db.changelog-master.xml: db/changelog/db.changelog-companyinfo_identifier.xml::add companyinfo.identifier::domi: Change Set db/changelog/db.changelog-companyinfo_identifier.xml::add add companyinfo.identifier::domi failed.  Error: Communications link failure

The last packet successfully received from the server was 7,200,055 milliseconds ago.  The last packet sent successfully to the server was 7,200,054 milliseconds ago. [Failed SQL: ALTER TABLE companyinfo ADD identifier VARCHAR(50) NULL]
INFO 5/2/17 7:11 PM: liquibase: db/changelog/db.changelog-companyinfo_identifier.xml::add companyinfo.identifier::domi: Successfully released change log lock
SEVERE 5/2/17 7:11 PM: liquibase: db/changelog/db.changelog-companyinfo_identifier.xml::add companyinfo.identifier::domi: Could not release lock
liquibase.exception.LockException: liquibase.exception.DatabaseException: Error executing SQL UPDATE DATABASECHANGELOGLOCK SET LOCKED = 0, LOCKEDBY = NULL, LOCKGRANTED = NULL WHERE ID = 1: No operations allowed after connection closed.
    at liquibase.lockservice.StandardLockService.releaseLock(StandardLockService.java:283)
    at liquibase.Liquibase.update(Liquibase.java:218)
    at liquibase.Liquibase.update(Liquibase.java:192)
    at liquibase.Liquibase.update(Liquibase.java:335)
    at org.liquibase.maven.plugins.LiquibaseUpdate.doUpdate(LiquibaseUpdate.java:33)
    at org.liquibase.maven.plugins.AbstractLiquibaseUpdateMojo.performLiquibaseTask(AbstractLiquibaseUpdateMojo.java:30)
    at org.liquibase.maven.plugins.AbstractLiquibaseMojo.execute(AbstractLiquibaseMojo.java:394)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:862)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: liquibase.exception.DatabaseException: Error executing SQL UPDATE DATABASECHANGELOGLOCK SET LOCKED = 0, LOCKEDBY = NULL, LOCKGRANTED = NULL WHERE ID = 1: No operations allowed after connection closed.
    at liquibase.executor.jvm.JdbcExecutor.execute(JdbcExecutor.java:68)
    at liquibase.executor.jvm.JdbcExecutor.update(JdbcExecutor.java:231)
    at liquibase.executor.jvm.JdbcExecutor.update(JdbcExecutor.java:205)
    at liquibase.lockservice.StandardLockService.releaseLock(StandardLockService.java:267)
    ... 28 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.Util.getInstance(Util.java:408)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:897)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:886)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)
    at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1198)
    at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1193)
    at com.mysql.jdbc.ConnectionImpl.createStatement(ConnectionImpl.java:2388)
    at com.mysql.jdbc.ConnectionImpl.createStatement(ConnectionImpl.java:2372)
    at liquibase.executor.jvm.JdbcExecutor.execute(JdbcExecutor.java:52)
    ... 31 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 7,200,055 milliseconds ago.  The last packet sent successfully to the server was 7,200,054 milliseconds ago.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)

当我运行与 Liquibase 从我的笔记本电脑执行的命令相同的命令时，不是通过 JDBC，而是从连接到上述相同数据库的 SequelPro MySql 客户端(瑞士的客户端，美国东海岸的数据库)中执行，它成功完成，没有任何大约 15 分钟内出现问题。

这些是 Liquibase 执行的语句:

--  *********************************************************************
--  Update Database Script
--  *********************************************************************
--  Change Log: src/main/resources/db/db.changelog-master.xml
--  Ran at: 5/3/17 7:55 AM
--  Against: XXXX@CCCCC@jdbc:mysql://yyyy.xxxx.net:3306/my_db?characterEncoding=utf8
--  Liquibase version: 3.5.3
--  *********************************************************************

--  Lock Database
UPDATE DATABASECHANGELOGLOCK SET LOCKED = 1, LOCKEDBY = 'xxxxx (192.168.1.24)', LOCKGRANTED = '2017-05-03 07:55:44.564' WHERE ID = 1 AND LOCKED = 0;

--  Changeset db/changelog/db.changelog-companyinfo_identifier.xml::add companyinfo.identifier::domi
ALTER TABLE companyinfo ADD identifier VARCHAR(50) NULL;

INSERT INTO DATABASECHANGELOG (ID, AUTHOR, FILENAME, DATEEXECUTED, ORDEREXECUTED, MD5SUM, DESCRIPTION, COMMENTS, EXECTYPE, CONTEXTS, LABELS, LIQUIBASE, DEPLOYMENT_ID) VALUES ('add companyinfo.identifier', 'domi', 'db/changelog/db.changelog-companyinfo_identifier.xml', NOW(), 838, '7:b2d3082917bf3ff3aecb6cbc363a5e9c', 'add companyinfo.identifier', '', 'EXECUTED', NULL, NULL, '3.5.3', '3790945685');

--  Changeset db/changelog/db.changelog-companyinfo_identifier.xml::add uk companyinfo.identifier::domi
ALTER TABLE companyinfo ADD CONSTRAINT uk_companyinfo_identifier UNIQUE (identifier);

INSERT INTO DATABASECHANGELOG (ID, AUTHOR, FILENAME, DATEEXECUTED, ORDEREXECUTED, MD5SUM, DESCRIPTION, COMMENTS, EXECTYPE, CONTEXTS, LABELS, LIQUIBASE, DEPLOYMENT_ID) VALUES ('add uk companyinfo.identifier', 'domi', 'db/changelog/db.changelog-companyinfo_identifier.xml', NOW(), 839, '7:5d98affa45f814b9ad32bc9c954ed32b', 'addUniqueConstraint constraintName=uk_companyinfo_identifier, tableName=companyinfo', '', 'EXECUTED', NULL, NULL, '3.5.3', '3790945685');

--  Release Database Lock
UPDATE DATABASECHANGELOGLOCK SET LOCKED = 0, LOCKEDBY = NULL, LOCKGRANTED = NULL WHERE ID = 1;

据我所知，数据库没有设置与 2 小时限制相匹配的超时:

• wait_timeout 设置为 28.8K 秒(8 小时)
• interactive_timeout:28800
• salve_net_timeout:3600(1 小时)
• connect_timeout:10
• lock_wait_timeout:31536000
• net_read_timeout:30
• net_write_timeout:60
• innodb_lock_wait_timeout:50

我认为有两个问题很有趣:

• 是什么导致 liquibase 在两小时后失败？
• 为什么 liquibase 的 DDL 执行速度这么慢？

...但也许两个问题都有相同的答案

<小时/>

更新:我已经执行了与我现在从本地环境中的 Jenkins 触发的完全相同的 maven/liquibase 命令(也连接到有问题的同一个远程数据库) - 你猜怎么着:它就像一个魅力，没有问题全部 - 命令在大约 20 分钟内完成!

mvn -f pom.xml process-resources -Pupdate-db -Dliquibase.username=xxx -Dliquibase.password=xxxx -Dliquibase.url=jdbc:mysql://yyyy.xxxx.net:3306/my_db:3306/yooture_ci?characterEncoding=utf8

所以我最后的猜测是，我们的 CI 基础设施和数据库之间一定存在某些东西导致了这个问题，但是是什么？它总是有效，只是在这种情况下不起作用......

Answer 1

我们终于找到了问题...

该问题是由默认 AWS NAT 配置引起的。 The AWS documentation说:

If a connection that's using a NAT gateway is idle for 5 minutes or more, the connection times out

它真的很低，而且肯定打破了大多数操作系统的默认配置。