MyCat是一个基于cobar兴起的开源数据库中间件系统，当前深受广大开源爱好者的追捧以及DBA粉丝们的广泛研究。主要是面对解决高并发，高负载，海量存储等屏颈。与任何应用软件一样，MyCAT也有自身的日志文件用于记录MyCAT运行时的相关信息用于排错与跟踪。本文主要描述其日志文件部分。
有关快速安装体验MyCAT请参考：快速体验MyCAT
一、日志配置
### 环境描述
### 当前基于windows 7安装了mycat
### 两台mysql主机，分别为192.168.1.204:3306,192.168.1.143:3307
###查看日志文件配置
D:\>type mycat\conf\log4j.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="ConsoleAppender" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{MM-dd HH:mm:ss.SSS} %5p [%t] (%F:%L) -%m%n" />
</layout>
</appender>
<appender name="FILE" class="org.apache.log4j.RollingFileAppender">
<param name="file" value="${MYCAT_HOME}/logs/mycat.log" /> //日志位置定义
<param name="Append" value="false"/> //记录方式，此时为append
<param name="MaxFileSize" value="1000KB"/> //每个日志文件大小
<param name="MaxBackupIndex" value="10"/> //保留个数
<param name="encoding" value="UTF-8" /> //字符集
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{MM/dd HH:mm:ss.SSS} %5p [%t] (%F:%L) -%m%n" />
</layout>
</appender>
<root>
<level value="info" /> //是日志的级别，生成环境下建议将级别调整为 info/ware。
//如果是研究测试，特别是碰到异常可以通过开启 debug 模式观察日志的信息查找异常原因。
<appender-ref ref="FILE" />
<!--<appender-ref ref="FILE" />-->
</root>
</log4j:configuration>
二、日志分析
1、warpper.log日志
warpper 日志：mycat启动，停止，添加为服务等都会记录到此日志文件，如果系统环境配置错误或缺少配置时，导致 Mycat 无法
启动，可以通过查看 warrpper.log 定位具体错误原因。
warrpper.log可以删除，删除后会自动重新生成该日志
###如果启动异常会有对应的异常信息，比如：
STATUS | wrapper | 2015/09/25 09:26:36 | --> Wrapper Started as Service
STATUS | wrapper | 2015/09/25 09:26:36 | Launching a JVM...
INFO | jvm 1 | 2015/09/25 09:26:37 | Wrapper (Version 3.2.3) http://wrapper.tanukisoftware.org
INFO | jvm 1 | 2015/09/25 09:26:37 | Copyright 1999-2006 Tanuki Software, Inc. All Rights Reserved.
INFO | jvm 1 | 2015/09/25 09:26:37 |
INFO | jvm 1 | 2015/09/25 09:26:37 |
INFO | jvm 1 | 2015/09/25 09:26:37 | WrapperSimpleApp: Encountered an error running main: java.lang.ExceptionInInitializerError
INFO | jvm 1 | 2015/09/25 09:26:37 | java.lang.ExceptionInInitializerError
INFO | jvm 1 | 2015/09/25 09:26:37 | at org.opencloudb.MycatStartup.main(MycatStartup.java:46)
INFO | jvm 1 | 2015/09/25 09:26:37 | at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
INFO | jvm 1 | 2015/09/25 09:26:37 | at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
INFO | jvm 1 | 2015/09/25 09:26:37 | at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
INFO | jvm 1 | 2015/09/25 09:26:37 | at java.lang.reflect.Method.invoke(Method.java:606)
INFO | jvm 1 | 2015/09/25 09:26:37 | at org.tanukisoftware.wrapper.WrapperSimpleApp.run(WrapperSimpleApp.java:240)
INFO | jvm 1 | 2015/09/25 09:26:37 | at java.lang.Thread.run(Thread.java:745)
INFO | jvm 1 | 2015/09/25 09:26:37 | Caused by: org.opencloudb.config.util.ConfigException: org.xml.sax.SAXParseException;
lineNumber: 26; columnNumber: 5; 元素类型 "dataHost" 必须由匹配的结束标记 "</dataHost>" 终止。 //这里说明了错误原因
INFO | jvm 1 | 2015/09/25 09:26:37 | ... 13 more
STATUS | wrapper | 2015/09/25 09:26:39 | <-- Wrapper Stopped
STATUS | wrapper | 2015/09/25 09:28:10 | --> Wrapper Started as Service
###正常启动状态的 warpper 日志为：
STATUS | wrapper | 2015/09/25 11:15:52 | Starting the Mycat-server service...
STATUS | wrapper | 2015/09/25 11:15:52 | --> Wrapper Started as Service
STATUS | wrapper | 2015/09/25 11:15:52 | Launching a JVM...
INFO | jvm 1 | 2015/09/25 11:15:52 | Wrapper (Version 3.2.3) http://wrapper.tanukisoftware.org
INFO | jvm 1 | 2015/09/25 11:15:52 | Copyright 1999-2006 Tanuki Software, Inc. All Rights Reserved.
INFO | jvm 1 | 2015/09/25 11:15:52 |
INFO | jvm 1 | 2015/09/25 11:15:53 | log4j 2015-09-25 11:15:53 [./conf/log4j.xml] load completed.
INFO | jvm 1 | 2015/09/25 11:15:53 | MyCAT Server startup successfully. see logs in logs/mycat.log
STATUS | wrapper | 2015/09/25 11:15:56 | Mycat-server started.
2、mycat.log日志
mycat.log为mycat主要日志文件，记录了启动时分配的相关buffer信息，数据源连接信息，连接池，动态类加载信息等等
在log4j.xml文件中进行相关配置，如保留个数，大小，字符集，日志文件大小等。
非启动状态下可以删除，启动后会自动生成该日志文件
日志的级别为info时的相关信息:
以下日志部分为描述了mycat初始相关参数的配置信息，如Mycat 线程池、 buffer、连接池等等所有的配置信息。
09/25 15:13:19.257 INFO [WrapperSimpleAppMain] (MycatServer.java:195) -===============================================
09/25 15:13:19.257 INFO [WrapperSimpleAppMain] (MycatServer.java:196) -MyCat is ready to startup ...
09/25 15:13:19.258 INFO [WrapperSimpleAppMain] (MycatServer.java:206) -Startup processors ...,total processors:4,aio thread pool size:8
each process allocated socket buffer pool bytes ,buffer chunk size:4096 buffer pool's capacity(buferPool/bufferChunk) is:4000
09/25 15:13:19.258 INFO [WrapperSimpleAppMain] (MycatServer.java:207) -sysconfig params:SystemConfig [processorBufferLocalPercent=100,
frontSocketSoRcvbuf=1048576, frontSocketSoSndbuf=4194304, backSocketSoRcvbuf=4194304, backSocketSoSndbuf=1048576, frontSocketNoDelay=1,
backSocketNoDelay=1, maxStringLiteralLength=65535, frontWriteQueueSize=2048, bindIp=0.0.0.0, serverPort=8066, managerPort=9066, charset=utf8,
processors=4, processorExecutor=8, timerExecutor=2, managerExecutor=2, idleTimeout=1800000, catletClassCheckSeconds=60, sqlExecuteTimeout=300,
processorCheckPeriod=1000, dataNodeIdleCheckPeriod=300000, dataNodeHeartbeatPeriod=10000, clusterHeartbeatUser=_HEARTBEAT_USER_,
clusterHeartbeatPass=_HEARTBEAT_PASS_, clusterHeartbeatPeriod=5000, clusterHeartbeatTimeout=10000, clusterHeartbeatRetry=10, txIsolation=3,
parserCommentVersion=50148, sqlRecordCount=10, processorBufferPool=16384000, processorBufferChunk=4096, defaultMaxLimit=100,
sequnceHandlerType=0, sqlInterceptor=org.opencloudb.interceptor.impl.DefaultSqlInterceptor, sqlInterceptorType=select,
sqlInterceptorFile=D:\mycat/logs/sql.txt, mutiNodeLimitType=0, mutiNodePatchSize=100, defaultSqlParser=druidparser, usingAIO=0,
packetHeaderSize=4, maxPacketSize=16777216, mycatNodeId=1]
09/25 15:13:19.277 INFO [WrapperSimpleAppMain] (MycatServer.java:266) -using nio network handler
09/25 15:13:19.290 INFO [WrapperSimpleAppMain] (MycatServer.java:284) -$_MyCatManager is started and listening on 9066
09/25 15:13:19.290 INFO [WrapperSimpleAppMain] (MycatServer.java:288) -$_MyCatServer is started and listening on 8066
以下部分为分片主机的相关信息，分别初始化了10个连接到2个不同的分片主机
这个是来自配置文件schema.xml里定义的dataHost中minCon="10"
09/25 15:13:19.290 INFO [WrapperSimpleAppMain] (MycatServer.java:290) -===============================================
09/25 15:13:19.291 INFO [WrapperSimpleAppMain] (MycatServer.java:293) -Initialize dataHost ...
09/25 15:13:19.291 INFO [WrapperSimpleAppMain] (PhysicalDBPool.java:272) -init backend myqsl source ,create connections total 10 for hostM1 index :0
09/25 15:13:19.291 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.293 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.293 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.294 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.294 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.294 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.294 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.294 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.295 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.295 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db1
09/25 15:13:19.309 INFO [$_NIOREACTOR-1-RW] (GetConnectionHandler.java:66) -connected successfuly MySQLConnection [id=1, lastTime=1443165199309,
schema=db1, old shema=db1, borrowed=true, fromSlaveDB=false, threadId=363, charset=latin1, txIsolation=0, autocommit=true, attachment=null,
respHandler=null, host=192.168.1.204, port=3306, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
09/25 15:13:19.309 INFO [$_NIOREACTOR-3-RW] (GetConnectionHandler.java:66) -connected successfuly MySQLConnection [id=3, lastTime=1443165199309,
schema=db1, old shema=db1, borrowed=true, fromSlaveDB=false, threadId=365, charset=latin1, txIsolation=0, autocommit=true, attachment=null,
respHandler=null, host=192.168.1.204, port=3306, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
..........
09/25 15:13:19.395 INFO [WrapperSimpleAppMain] (PhysicalDBPool.java:301) -init result :finished 10 success 10 target count:10
09/25 15:13:19.395 INFO [WrapperSimpleAppMain] (PhysicalDBPool.java:243) -192.168.1.204 index:0 init success
09/25 15:13:19.395 INFO [WrapperSimpleAppMain] (PhysicalDBPool.java:272) -init backend myqsl source ,create connections total 10 for hostM1 index :0
09/25 15:13:19.396 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.396 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.396 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.396 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.397 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.397 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.398 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.398 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.399 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.400 INFO [WrapperSimpleAppMain] (PhysicalDatasource.java:373) -not ilde connection in pool,create new connection for hostM1 of schema db2
09/25 15:13:19.409 INFO [$_NIOREACTOR-1-RW] (GetConnectionHandler.java:66) -connected successfuly MySQLConnection [id=13, lastTime=1443165199409,
schema=db2, old shema=db2, borrowed=true, fromSlaveDB=false, threadId=6232, charset=latin1, txIsolation=0, autocommit=true, attachment=null,
respHandler=null, host=192.168.1.143, port=3307, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
09/25 15:13:19.410 INFO [$_NIOREACTOR-1-RW] (GetConnectionHandler.java:66) -connected successfuly MySQLConnection [id=17, lastTime=1443165199410,
schema=db2, old shema=db2, borrowed=true, fromSlaveDB=false, threadId=6235, charset=latin1, txIsolation=0, autocommit=true, attachment=null,
respHandler=null, host=192.168.1.143, port=3307, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
...........
09/25 15:13:19.500 INFO [WrapperSimpleAppMain] (PhysicalDBPool.java:301) -init result :finished 10 success 10 target count:10
09/25 15:13:19.500 INFO [WrapperSimpleAppMain] (PhysicalDBPool.java:243) -192.168.1.143 index:0 init success
以下部分是一个成功连接到9066的信息
09/25 15:13:51.468 INFO [$_NIOREACTOR-1-RW] (FrontendAuthenticator.java:164) -[thread=$_NIOREACTOR-1-RW,
class=ManagerConnection,id=1,host=0:0:0:0:0:0:0:1,port=9066,schema=testdb]'test' login success
日志的级别为debug时的相关信息:
修改日志配置文件log4j.xml，value值改为"debug"，如下：
<level value="debug" />
mysql:9600>reload @@config_all;
Query OK, 1 row affected (0.23 sec)
Reload config success
--发布查询
mysql:8066>select * from goods;
+----+-------+
| id | val |
+----+-------+
| 1 | apple |
+----+-------+
--相关的日志信息，//这里为路由的信息，即sql最终在哪个分片节点执行
09/25 15:52:07.235 DEBUG [$_NIOREACTOR-0-RW] (ServerQueryHandler.java:56) -ServerConnection [id=4, schema=testdb, host=0:0:0:0:0:0:0:1,
user=test,txIsolation=3, autocommit=true, schema=testdb]select * from goods
09/25 15:52:07.235 DEBUG [$_NIOREACTOR-0-RW] (EnchachePool.java:76) -SQLRouteCache miss cache ,key:testdbselect * from goods
09/25 15:52:07.236 DEBUG [$_NIOREACTOR-0-RW] (NonBlockingSession.java:113) -ServerConnection [id=4, schema=testdb, host=0:0:0:0:0:0:0:1,
user=test,txIsolation=3, autocommit=true, schema=testdb]select * from goods, route={
1 -> dn2{SELECT *
FROM goods
LIMIT 100}
} rrs
09/25 15:52:07.236 DEBUG [$_NIOREACTOR-0-RW] (PhysicalDBPool.java:431) -select read source hostM1 for dataHost:192.168.1.143
09/25 15:52:07.236 DEBUG [$_NIOREACTOR-0-RW] (MySQLConnection.java:442) -con need syn ,total syn cmd 2 commands SET names gbk;
SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;schema change:false con:MySQLConnection [id=33, lastTime=1443167527236,
schema=db2, old shema=db2, borrowed=true, fromSlaveDB=false, threadId=6242, charset=latin1, txIsolation=0, autocommit=true, attachment=dn2{SELECT *
FROM goods
LIMIT 100}, respHandler=SingleNodeHandler [node=dn2{SELECT *
FROM goods
LIMIT 100}, packetId=0], host=192.168.1.143, port=3307, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
09/25 15:52:07.238 DEBUG [$_NIOREACTOR-2-RW] (NonBlockingSession.java:230) -release connection MySQLConnection [id=33,
lastTime=1443167527222, schema=db2, old shema=db2, borrowed=true, fromSlaveDB=false, threadId=6242, charset=gbk,
txIsolation=3, autocommit=true, attachment=dn2{SELECT *
FROM goods
LIMIT 100}, respHandler=SingleNodeHandler [node=dn2{SELECT *
FROM goods
LIMIT 100}, packetId=5], host=192.168.1.143, port=3307, statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@9d2f333, writeQueue=0,
modifiedSQLExecuted=false]
09/25 15:52:07.238 DEBUG [$_NIOREACTOR-2-RW] (PhysicalDatasource.java:403) -release channel MySQLConnection
[id=33, lastTime=1443167527222, schema=db2, old shema=db2, borrowed=true, fromSlaveDB=false, threadId=6242, charset=gbk,
txIsolation=3, autocommit=true, attachment=null, respHandler=null, host=192.168.1.143, port=3307, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
09/25 15:52:09.508 DEBUG [Timer1] (SQLJob.java:85) -con query sql:select user() to con:MySQLConnection [id=26,
lastTime=1443167529508, schema=db1, old shema=db1, borrowed=true, fromSlaveDB=false, threadId=376, charset=latin1,
txIsolation=0, autocommit=true, attachment=null, respHandler=null, host=192.168.1.204, port=3306, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
09/25 15:52:09.508 DEBUG [Timer1] (SQLJob.java:85) -con query sql:select user() to con:MySQLConnection [id=32,
lastTime=1443167529508, schema=db2, old shema=db2, borrowed=true, fromSlaveDB=false, threadId=6245, charset=latin1,
txIsolation=0, autocommit=true, attachment=null, respHandler=null, host=192.168.1.143, port=3307, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
09/25 15:52:09.509 DEBUG [$_NIOREACTOR-3-RW] (PhysicalDatasource.java:403) -release channel MySQLConnection [id=26, lastTime=1443167529502, schema=db1,
old shema=db1, borrowed=true, fromSlaveDB=false, threadId=376, charset=latin1, txIsolation=0, autocommit=true, attachment=null, respHandler=null,
host=192.168.1.204, port=3306, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
09/25 15:52:09.509 DEBUG [$_NIOREACTOR-1-RW] (PhysicalDatasource.java:403) -release channel MySQLConnection [id=32, lastTime=1443167529502, schema=db2,
old shema=db2, borrowed=true, fromSlaveDB=false, threadId=6245, charset=latin1, txIsolation=0, autocommit=true, attachment=null, respHandler=null,
host=192.168.1.143, port=3307, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
以下部分是一个分布在既分布在dn1，又分布在dn2上日志路由信息
09/25 16:30:26.641 DEBUG [$_NIOREACTOR-0-RW] (EnchachePool.java:76) -SQLRouteCache miss cache ,key:testdbselect * from travelrecord
09/25 16:30:26.649 DEBUG [$_NIOREACTOR-0-RW] (EnchachePool.java:59) -SQLRouteCache add cache ,key:testdbselect * from travelrecord value:select *
from travelrecord, route={
1 -> dn1{SELECT *
FROM travelrecord
LIMIT 100}
2 -> dn2{SELECT *
FROM travelrecord
LIMIT 100}
}
09/25 16:30:26.649 DEBUG [$_NIOREACTOR-0-RW] (NonBlockingSession.java:113) -ServerConnection [id=4, schema=testdb, host=0:0:0:0:0:0:0:1,
user=test,txIsolation=3, autocommit=true, schema=testdb]select * from travelrecord, route={
1 -> dn1{SELECT *
FROM travelrecord
LIMIT 100}
2 -> dn2{SELECT *
FROM travelrecord
LIMIT 100}
} rrs
09/25 16:30:26.650 DEBUG [$_NIOREACTOR-0-RW] (MultiNodeQueryHandler.java:83) -execute mutinode query select * from travelrecord
09/25 16:30:26.668 DEBUG [$_NIOREACTOR-0-RW] (MultiNodeQueryHandler.java:98) -has data merge logic