【错误处理】-211 Cannot read system catalog

应用错误日志：（URL中IFX_LOCK_MODE_WAIT=10）

Caused by: java.sql.SQLException: Cannot read system catalog (systables).
    at com.gbasedbt.jdbc.IfxSqli.a(IfxSqli.java:3570)
    at com.gbasedbt.jdbc.IfxSqli.D(IfxSqli.java:3852)
    at com.gbasedbt.jdbc.IfxSqli.dispatchMsg(IfxSqli.java:2738)
    at com.gbasedbt.jdbc.IfxSqli.receiveMessage(IfxSqli.java:2663)
    at com.gbasedbt.jdbc.IfxSqli.executePrepare(IfxSqli.java:1290)
    at com.gbasedbt.jdbc.IfxPreparedStatement.f(IfxPreparedStatement.java:485)
    at com.gbasedbt.jdbc.IfxPreparedStatement.a(IfxPreparedStatement.java:466)
    at com.gbasedbt.jdbc.IfxPreparedStatement.<init>(IfxPreparedStatement.java:268)
    at com.gbasedbt.jdbc.IfxSqliConnect.h(IfxSqliConnect.java:6339)
    at com.gbasedbt.jdbc.IfxSqliConnect.prepareStatement(IfxSqliConnect.java:2542)
    at com.alibaba.druid.filter.FilterChainImpl.connection_prepareStatement(FilterChainImpl.java:535)
    at com.alibaba.druid.filter.FilterAdapter.connection_prepareStatement(FilterAdapter.java:908)
    at com.alibaba.druid.filter.FilterEventAdapter.connection_prepareStatement(FilterEventAdapter.java:116)
    at com.alibaba.druid.filter.FilterChainImpl.connection_prepareStatement(FilterChainImpl.java:531)
    at com.alibaba.druid.proxy.jdbc.ConnectionProxyImpl.prepareStatement(ConnectionProxyImpl.java:326)
    at com.alibaba.druid.pool.DruidPooledConnection.prepareStatement(DruidPooledConnection.java:362)
    at org.apache.ibatis.executor.statement.PreparedStatementHandler.instantiateStatement(PreparedStatementHandler.java:86)
    at org.apache.ibatis.executor.statement.BaseStatementHandler.prepare(BaseStatementHandler.java:88)
    at org.apache.ibatis.executor.statement.RoutingStatementHandler.prepare(RoutingStatementHandler.java:59)
    at org.apache.ibatis.executor.ReuseExecutor.prepareStatement(ReuseExecutor.java:89)
    at org.apache.ibatis.executor.ReuseExecutor.doQuery(ReuseExecutor.java:59)
    at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:325)
    at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
    at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:151)
    at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:62)
    at com.sun.proxy.$Proxy583.query(Unknown Source)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:151)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:145)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
    at sun.reflect.GeneratedMethodAccessor262.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:427)
    ... 134 common frames omitted
Caused by: java.sql.SQLException: ISAM error: Lock Timeout Expired
    at com.gbasedbt.util.IfxErrMsg.getSQLException(IfxErrMsg.java:408)
    at com.gbasedbt.jdbc.IfxSqli.D(IfxSqli.java:3857)
    ... 166 common frames omitted

相关错误号：

-211    Cannot read system catalog <error-text\> # 无法读取系统目录 <error-text>。
-154    ISAM error: Lock Timeout Expired. # ISAM错误: 锁定因超时而失效。
-144    ISAM error: key value locked.  # ISAM 错误: 键值被锁定。
-107    ISAM error: record is locked.  # ISAM错误: 记录被锁定。

错误原因：查询的表正在执行ddl操作，表已被锁。如：alter table,create index等。

解决方案：设置锁等待，或稍后重试。或kill锁表的会话。

SQL查找锁表会话：(库名表名替换为目标库名表名)

select first 1 owner as sid from sysmaster:syslocks where dbsname='testdb' and tabname='t';

onstat查找锁表会话：（t为表名，替换为目标表名）

echo "set isolation to dirty read;select lower(hex(partnum)) from systables where tabname='t'" |dbaccess testdb
#输出：
0x00200047
#查找锁表的线程：
onstat -k |grep 200047
#输出：（需要第三列地址46163728）
448b7300         0                46163728           448b57e8         HDR+X    200047   0           0
#查找sessionid：
onstat -u |grep 46163728
#输出：(需要第三列sessionid）
46163728         Y-BP--- 165      gbasedbt 0        47747468         0    18    0        66

查看锁表sql：

onstat -g ses 165

kill会话：

onmode -z 165

以下操作可重现：