mysqlkillprocess解决死锁问题

mysql kill process解决死锁

mysql死锁异常分析及解决

问题产生

原因分析

解决方案

mysql kill process解决死锁

1、查看进程列表，找到ID

show processlist;
+--------+--------+--------------------+----------+---------+------+----------+------------------+
| Id     | User   | Host               | db       | Command | Time | State    | Info             |
+--------+--------+--------------------+----------+---------+------+----------+------------------+
|      8 | remote | 10.16.30.96:36592  | activity | Sleep   |  239 |          | NULL             |
| 396749 | remote | 172.17.1.122:53028 | activity | Sleep   | 1966 |          | NULL             |
| 397104 | remote | 172.17.3.211:52666 | activity | Sleep   |    7 |          | NULL             |
| 397177 | remote | 172.17.3.211:52819 | activity | Sleep   | 7366 |          | NULL             |
| 397267 | remote | 172.17.1.122:55728 | activity | Sleep   | 5741 |          | NULL             |
| 397268 | remote | 172.17.1.122:55730 | activity | Sleep   | 7849 |          | NULL             |
| 397287 | remote | 172.17.3.150:57151 | activity | Sleep   | 7128 |          | NULL             |
| 397294 | remote | 172.17.3.68:53158  | activity | Sleep   | 2882 |          | NULL             |
| 397296 | remote | 172.17.3.68:53160  | NULL     | Sleep   | 6492 |          | NULL             |

2、查询语句把表锁住了, 赶紧找出第一个Locked的thread_id, 在MySQL的shell里面执行.

kill  id
#!/bin/bash
mysql  - u   root  - e   " show processlist "  |  grep  - i   " Locked "  >>  locked_log . txt
for   line   in   ` cat locked_log.txt | awk '{print  $1 }' `
do  
    echo   " kill  $line ; "  >>  kill_thread_id . sql
done

现在kill_thread_id.sql的内容像这个样子

kill   66402982 ;
kill   66402983 ;
kill   66402986 ;
kill   66402991 ;
.....

好了, 我们在mysql的shell中执行, 就可以把所有锁表的进程杀死了.

mysql > source kill_thread_id . sql

当然了, 也可以一行搞定

for id in `mysqladmin processlist | grep -i locked | awk '{print $1}'`
do
   mysqladmin kill ${id}
done
;

mysql死锁异常分析及解决

其实在这次之前也发生过死锁异常，但当时并没当回事，也没分析数据，简单的认为是偶发现象，并且是修改同一用户产生，于是就在最初添加了select for update，直到这两天发生了好几笔，分析数据发现并不是之前猜测的那样

问题产生

这两天老接到运维通知，说某客户又发生了卡单现象，让我分析下问题，然后找来日志，异常信息如下：

### Error updating database. Cause: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
### The error may involve io.renren.modules.others.dao.PlayerDao.saveZhsz-Inline
### The error occurred while setting parameters
### SQL: INSERT INTO shpt_zhgl_zhsz(rq, jysr, ztzhye, zhye, shid) select ?, ?, zhye, zhye + ?, user_id from sys_user where user_id = ? ON DUPLICATE KEY UPDATE jysr = jysr + values(jysr), zhye = values(zhye)
### Cause: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
; Deadlock found when trying to get lock; try restarting transaction; nested exception is com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction

org.springframework.dao.DeadlockLoserDataAccessException:
### Error updating database. Cause: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
### The error may involve io.renren.modules.others.dao.PlayerDao.saveZhsz-Inline
### The error occurred while setting parameters
### SQL: INSERT INTO shpt_zhgl_zhsz(rq, jysr, ztzhye, zhye, shid) select ?, ?, zhye, zhye + ?, user_id from sys_user where user_id = ? ON DUPLICATE KEY UPDATE jysr = jysr + values(jysr), zhye = values(zhye)
### Cause: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
; Deadlock found when trying to get lock; try restarting transaction; nested exception is com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
   at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:267)
   at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72)
   at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73)
   at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446)
   at com.sun.proxy.$Proxy84.update(Unknown Source)
   at org.mybatis.spring.SqlSessionTemplate.update(SqlSessionTemplate.java:294)
   at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:62)
   at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
   at com.sun.proxy.$Proxy115.saveZhsz(Unknown Source)
   at io.renren.modules.others.service.PlayerService.updateOrder(PlayerService.java:195)
   at io.renren.modules.others.service.PlayerService$$FastClassBySpringCGLIB$$cd68b7fd.invoke(<generated>)
   at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
   at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769)
   at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
   at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
   at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366)
   at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99)
   at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
   at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
   at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)
   at io.renren.modules.others.service.PlayerService$$EnhancerBySpringCGLIB$$5688f237.updateOrder(<generated>)
   at io.renren.modules.others.service.PlayerService$$FastClassBySpringCGLIB$$cd68b7fd.invoke(<generated>)
   at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
   at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769)
   at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
   at org.springframework.a op.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
   at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366)
   at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99)
   at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
   at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
   at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)
   at io.renren.modules.others.service.PlayerService$$EnhancerBySpringCGLIB$$2c59a973.updateOrder(<generated>)
   at io.renren.modules.others.controller.PlayerController.a(PlayerController.java:967)
   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.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
   at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
   at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)
   at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888)
   at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)
   at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
   at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
   at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
   at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
   at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
   at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:112)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at io.renren.common.xss.XssFilter.doFilter(XssFilter.java:23)
&nb sp; at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
   at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
   at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
   at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
   at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
   at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
   at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
   at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
   at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
   at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
   at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
   at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
   at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358)
   at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at io.renren.config.LicenseFilter.doFilter(LicenseFilter.java:136)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at io.renren.config.FilterConfig$1.doFilterInternal(FilterConfig.java:82)
   at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
   at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
   at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
   at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
; at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
   at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
   at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
   at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
   at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
   at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
   at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
   at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
   at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
   at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
   at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860)
   at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1598)
   at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
   at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
   at java.lang.Thread.run(Thread.java:748)
Caused by: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
   at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:123)
   at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
   at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
   at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:955)
   at com.mysql.cj.jdbc.ClientPreparedStatement.execute(ClientPreparedStatement.java:372)
   at com.alibaba.druid.pool.DruidPooledPreparedStatement.execute(DruidPooledPreparedStatement.java:497)
   at sun.reflect.GeneratedMethodAccessor53.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:498)
   at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:59)
   at com.sun.proxy.$Proxy119.execute(Unknown Source)
   at org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:46)
   at org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:74)
   at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:50)
   at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117)
   at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76)
   at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:198)
   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.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)
   ... 108 common frames omitted

异常复现

分析日志发现，出现的几次都是在并发时发生，并且商户都有上级代理，本地并发测试，成功复现

原因分析

数据库相关锁的概念在此不赘述，具体请自行度娘

数据库运行命令：

show engine innodb status

得到日志，主要分析如下片段，是最后一次死锁信息:

------------------------
LATEST DETECTED DEADLOCK
------------------------
2021-03-16 09:56:00 0x3444
*** (1) TRANSACTION:
TRANSACTION 5245990, ACTIVE 0 sec inserting
mysql tables in use 2, locked 2
LOCK WAIT 5 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 4949, OS thread handle 14000, query id 980983 180.126.46.39 root Sending data
INSERT INTO shpt_zhgl_zhsz(rq, jysr, ztzhye, zhye, shid) select '2021-03-13', 8.03, zhye, zhye + 8.03, user_id from sys_user where user_id = 32 ON DUPLICATE KEY UPDATE jysr = jysr + values(jysr), zhye = values(zhye)
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 233 page no 3 n bits 168 index PRIMARY of table `zfpt`.`shpt_zhgl_zhsz` trx id 5245990 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;

*** (2) TRANSACTION:
TRANSACTION 5245989, ACTIVE 0 sec setting auto-inc lock
mysql tables in use 2, locked 2
9 lock struct(s), heap size 1136, 6 row lock(s), undo log entries 2
MySQL thread id 4950, OS thread handle 13380, query id 980987 180.126.46.39 root Sending data
INSERT INTO shpt_zhgl_zhsz(rq, dlsr, ztzhye, zhye, shid) select '2021-03-13', 1.00, zhye, zhye + 1.00, user_id from sys_user where user_id = 1 ON DUPLICATE KEY UPDATE dlsr = dlsr + values(dlsr), zhye = values(zhye)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 233 page no 3 n bits 168 index PRIMARY of table `zfpt`.`shpt_zhgl_zhsz` trx id 5245989 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;

*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
TABLE LOCK table `zfpt`.`shpt_zhgl_zhsz` trx id 5245989 lock mode AUTO-INC waiting
*** WE ROLL BACK TRANSACTION (1)

原来是并发时在业务中INSERT INTO shpt_zhgl_zhsz ON DUPLICATE KEY UPDATE这个商户时，有其他商户也在运行INSERT INTO shpt_zhgl_zhsz ON DUPLICATE KEY UPDATE，而又由于商户拥有上级代理，也会NSERT INTO shpt_zhgl_zhsz ON DUPLICATE KEY UPDATE上级代理的数据，从而产生了死锁

解决方案

1、mysql默认级别repeatable read导致的死锁问题，所以根据业务，决定修改隔离级别为 read committed，从而解决死锁问题

@Transactional(isolation = Isolation.READ_COMMITTED)
public int updateOrder(BigDecimal je, String status, String orderNo, String zfsj) {
    // xxxxx相关业务
}

2、可以在死锁业务外面添加循环，捕获死锁异常，发生死锁异常时循环执行，正常执行时结束循环

3、添加全局异常捕获器，在捕获器中获取本次请求的方法类型(GET/POST…)，方法路径，方法参数，contentType等等，重新请求一次

@ControllerAdvice
public class GlobalExceptionHandler {
    private Logger logger = LoggerFactory.getLogger(getClass());
    // 这是异常锁表，lock wait timeout导致业务失败时的处理，也是比较常见的问题
    @ResponseBody
    @ExceptionHandler(CannotAcquireLockException.class)
    public String cannotAcquireLockException(CannotAcquireLockException e) {
        DruidDataSource dds = SpringContextUtils.getBean("firstDataSource", DruidDataSource.class);
        try (DruidPooledConnection conn = dds.getConnection();
                Statement stmt = conn.createStatement();
                ResultSet rs = stmt.executeQuery("select trx_mysql_thread_id from INFORMATION_SCHEMA.INNODB_TRX"
                        + " where trx_state = 'RUNNING' and trx_started < adddate(now(), INTERVAL -60 SECOND)");
                PreparedStatement ps = conn.prepareStatement("kill ?")) {
            while (rs.next()) {
                ps.setLong(1, rs.getLong(1));
                ps.addBatch();
            }
            ps.executeBatch();
        } catch (SQLException ex) {
            logger.error(ex.getMessage(), ex);
        }
        logger.error(e.getMessage(), e);
        return "{\"code\": 500, \"msg\": \"acquire lock failure, already kill the lock thread, try again\"}";
    }
    // 笔者没有实现这种方式，只是返回了对应异常信息
    @ResponseBody
    @ExceptionHandler(DeadlockLoserDataAccessException.class)
    public String deadLockException(DeadlockLoserDataAccessException e) {
        logger.error(e.getMessage(), e);
        return "{\"code\": 500, \"msg\": \"deadlock found when trying to get lock, try again\"}";
    }
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持易知道(ezd.cc)。