mongo 学习

unijun

mongod 启动参数详解：
--fastsync
--oplogSize arg size limit(in MB) for op log


--master  master mode
--slave   slave mode
--source arg <serverIp:port> if slave mode ,specify master. if master mode , specify slave ;
--only arg   if slave mode , specify a single db to rep
--slavedelay arg delay time in seconds
<wbr style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">--autoresync<span style="white-space:pre"> </span>automatically resync if slave data is stale</div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><br></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><br></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><br></div><span style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">主从配置</span><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">master 启动： ./mongod --dbpath /data/db/master --logpath /data/db/master.log --logappend --fork --port 2717 --master --oplogSize 64</div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><br></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">slave 启动： ./mongod --dbpath /data/db/slave --logpath /data/db/slaver.log --logappend --fork -port 27018 --slave --slavedelay 5 --autoresync --source localhost:27017 </div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><br></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><strong>问题解决：</strong></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">1.Client::~Client _context should be null but is not; client:replslave</div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">从库启动，同步时报错自动关闭；需要删除从库db目录下的记录即可。</div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><strong>参考：</strong></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-size:12px; line-height:23px">注意:这里,最好是用scp命令把主机器的mongodb的所有目录和文件远程拷贝<br><span style="white-space:pre"></span>到从机器上去, 之前不要去启动,主机器,否则启动从的时候会报错(在<br><span style="white-space:pre"></span>日志文件中可以看到错误:mongodb ERROR: Client::~Client _context should be null but is not; client:replslave)<br><span style="white-space:pre"></span>这样的话, 只需要把数据文件data目录下的所有文件删除,重新启动即可</span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><br></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">2. mongodb 启动失败，因为非法关闭造成</div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px">摘自：<a rel="nofollow" href="http://codingstandards.iyunv.com/blog/1214093" style="color:rgb(121,75,21); text-decoration:initial">http://codingstandards.iyunv.com/blog/1214093</a></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="color:rgb(255,0,0); font-family:Helvetica,Tahoma,Arial,sans-serif">mongod没有后台执行，在终端连接非正常断开后，再次执行mongod报错，需要repair修复；</span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif">[initandlisten] exception in initAndListen: 12596 old lock file, terminating</span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif">dbexit</span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><div style="font-weight:bold; padding:5px; margin:5px 0px 0px 15px; font-family:Helvetica,Tahoma,Arial,sans-serif">http://www.mongodb.org/display/DOCS/Durability+and+Repair#DurabilityandRepair-RepairCommand 写道</div><div style="border:1px solid rgb(204,204,204); margin:0px 5px 5px 15px; padding:3px; background-color:rgb(250,250,250); font-family:Helvetica,Tahoma,Arial,sans-serif">Repair Command<br><br>When not using journaling (--nojournal), after a machine crash or kill -9 termination, run the repairDatabase command. This command will check all data for corruption, remove any corruption found, and compact data files a bit. Repair is analogous to runningfsck for a file system.<br><br>When journaling is enabled, it should not be necessary to run repair. However one could still use the repair command to compact a database.<br><br>From the command line:<br><br>mongod --repair<br><br>From the shell (you have to do for all dbs including local if you go this route):<br><br>&gt; db.repairDatabase();<br><br>During a repair operation, mongod must store temporary files to disk. By default, mongod creates temporary directories under the dbpath for this purpose. Alternatively, the --repairpath command line option can be used to specify a base directory for temporaryrepair files.<br><br>Note that repair is a slow operation which inspects the entire database.<br><br>After running with --repair, mongod will start up normally.</div></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><br></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><div> </div></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><br></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><strong>互为主从配置</strong></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif">摘自：</span><span style="font-family:Helvetica,Tahoma,Arial,sans-serif">http://blog.csdn.net/liuyuanshijie/article/details/6735625</span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><br></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><br></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><strong>Replic Sets配置：</strong></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><strong>摘自： http://virusswb.blog.iyunv.com/115214/792897</strong></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><br></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">MongoDB支持两种复制的模式：</p><ol style="margin:5px 0px 5px 40px; padding:0px"><li>Master/Slave，主从复制，角色包括master和slave。</li><li>Replica Set，复制集复制，角色包括primary和secondary。</li></ol><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">介绍Master/Slave的官方地址：</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><a target="_blank" rel="nofollow" href="http://www.mongodb.org/display/DOCS/Master+Slave" style="color:rgb(121,75,21); text-decoration:initial">http://www.mongodb.org/display/DOCS/Master+Slave</a></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">介绍Replica Set的官方地址：</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><a target="_blank" rel="nofollow" href="http://www.mongodb.org/display/DOCS/Replica+Sets" style="color:rgb(121,75,21); text-decoration:initial">http://www.mongodb.org/display/DOCS/Replica+Sets</a></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">今天实战的是replica set，也就是复制集复制。</p><ul style="margin:5px 0px 5px 40px; padding:0px"><li>replica set可以实现自动的failover和自动的recovery。</li><li>replica set由两个或者更多的节点组成，实现彼此的复制。</li><li>replica set自动选择primary节点，没有一个节点是固定的primary。</li><li>mongos会自动发现一个replica set的primary节点发生变化，并将写操作发送给这个新的primary节点。</li></ul><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">通常用于下面几个场景</p><ul style="margin:5px 0px 5px 40px; padding:0px"><li>数据冗余。</li><li>自动failover，提供高可用性的服务。</li><li>分散读的负载。</li><li>简化维护(相对于master-slave来说）。</li><li>灾难恢复。</li></ul><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">首先还是启动mongod，用于replica set的参数有两个：</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><tt>--replSet &lt;setname&gt;，复制集的名称。</tt></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><tt>--oplogSize &lt;MB&gt;，操作日志的大小，单位为MB。</tt></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">这回我们在ubuntu下面配置replica set，先启动两个mongod节点。<br></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">mongod--dbpath/home/andyshi/mongo1/--logpath/home/andyshi/mongo1/log.log--replSetshard1--port10001--bind_ip192.168.0.21</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">mongod--dbpath/home/andyshi/mongo2/--logpath/home/andyshi/mongo2/log.log--replSetshard1--port10002--bind_ip192.168.0.21</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">你会注意到，上面两个mongod的启动参数replSet指定了相同的值shard1，也就是两个个mongod节点处于同一个replica set中。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">Replica Set的初始化</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">光启动了两个个mongod节点，还不能提供任何的服务，这时候你使用mongo连接之后，进行db.book.insert会提示你no master，也就是说没有primary节点，所以他不知道往哪一个节点写入数据。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">在启动了两个个mongod节点之后，需要进行初始化。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">首先用mongo连接到任意一个mongod节点，然后执行下面的命令。</p><pre><ol style="margin:5px 0px 5px 40px; padding:0px"><li>cfg={_id:'shard1',members:[</li><li>{_id:0,host:'192.168.0.21:10001'},</li><li>{_id:1,host:'192.168.0.21:10002'}]</li><li>}</li><li>rs.initiate(cfg)</li></ol></pre><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">出现下面的提示信息就代表成功了，如果没有成功，可以google一下错误提示，会找到很多的答案的。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"></p><pre><ol style="margin:5px 0px 5px 40px; padding:0px"><li>{</li><li>"info":"Confignowsavedlocally.Shouldcomeonlineinaboutaminute.",</li><li>"ok":1</li><li>}</li></ol></pre><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">继续执行</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">rs.status()</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">可以查看replica set的状态，包括名称，时间，当前登录的mongod是primary还是secondary，以及成员的信息等。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">在replica set的信息中，其中重要的是：</p><ul style="margin:5px 0px 5px 40px; padding:0px"><li>myState的值，如果是1代表当前登录的是primary；如果是2代表当前登录的是secondary。</li></ul><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">成员信息中包括地址，健康状态，是primary还是secondary等。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">成员信息中比较重要的是</p><ul style="margin:5px 0px 5px 40px; padding:0px"><li><span style="line-height:21px; font-family:宋体,Arial; background-color:rgb(245,247,248)">state：1表示该host是当前可以进行读写，2：不能读写</span></li><li><span style="line-height:21px; font-family:宋体,Arial; background-color:rgb(245,247,248)">health：1表示该host目前是正常的，0:异常</span></li></ul><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">这时候登录primary的mongod，插入一条数据。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"></p><pre><ol style="margin:5px 0px 5px 40px; padding:0px"><li>//假设10001是primary，可以通过查询rs.status来获取</li><li>mongo192.168.0.21:10001</li><li><li>usetest</li><li>db.book.insert({'title':'computer'})</li></ol></pre><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">然后查看secondary的log文件，会发现发生了复制行为。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">这时候登录secondary，use test，db.book.find()，可以报错了。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"></p><pre><ol style="margin:5px 0px 5px 40px; padding:0px"><li>error:{"$err":"notmasterandslaveok=false","code":13435}</li></ol></pre><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">没有关系，在secondary读取数据还需要我们做最后的一步，在需要读取数据的secondary上执行。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">rs.slaveOK()</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">这时候再次db.book.find()，正常显示结果了，没有问题了。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">添加节点</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">启动新mongod节点</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">mongod--dbpath/home/andyshi/mongo3/--logpath/home/andyshi/mongo3/log.log--replSetshard1--port10003--bind_ip192.168.0.21</p><pre></pre><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">连接primary节点，执行下面的命令。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"></p><pre><ol style="margin:5px 0px 5px 40px; padding:0px"><li>rs.add('192.168.0.21:10003')</li><li>rs.addArb('192.168.0.21:10003')</li><li>//重新配置</li><li>rs.reconfig(rs.conf())</li></ol></pre><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">强制一个节点成为primary</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">在mongodb2.0之后可以使用下面</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">相比master-slave，replica set的优点就是没有单点故障，primary故障之后，整个replica set会自动选择一个健康的节点成为primary，承担写的任务，可用性比master-slave的高，提供更高的可用性。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><br></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><strong>遇到的问题：</strong></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">在replset运行正常的情况下，停止服务，更换端口，重新分配set，造成的问题。</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">可通过use admin  db.runcommand({replSetReconfig:config})从新分配，其中config={} 是set的新配置；当此法还无法解决问题时，可以更改local.system.replset的记录，或者重做local表了</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">具体可借鉴：<a rel="nofollow" href="http://groups.google.com/group/mongoid/browse_thread/thread/6291b8b80158031e" style="color:rgb(121,75,21); text-decoration:initial">http://groups.google.com/group/mongoid/browse_thread/thread/6291b8b80158031e</a></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><a rel="nofollow" href="http://blog.nroed.com/2011/12/15/mongo-replset-badconfig/?replytocom=489" style="color:rgb(121,75,21); text-decoration:initial">http://blog.nroed.com/2011/12/15/mongo-replset-badconfig/?replytocom=489</a></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px"><a rel="nofollow" href="http://groups.google.com/group/mongoid/browse_thread/thread/6291b8b80158031e?pli=1" style="color:rgb(121,75,21); text-decoration:initial">http://groups.google.com/group/mongoid/browse_thread/thread/6291b8b80158031e?pli=1</a></p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">run rs.initiate(...) if not yet done for the set</p><p style="margin-top:0px; margin-bottom:10px; padding-top:0px; padding-bottom:0px">local.oplog.rs is not empty on the initiating member. cannot initiate.</p></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif">loading local.system.replset config (LOADINGCONFIG)</span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif"><br></span></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><br></div><div style="line-height:25px; color:rgb(78,78,78); font-family:Arial,Helvetica,simsun,u5b8bu4f53; font-size:14px"><strong>集群配置</strong></div><br></wbr>