title: start mongos failed
body: <p>I have three mongod shard process and three mongod config server in different server.</p>
  
  <p>The deploy:</p>
  
  <p>ShardA on server 192.168.2.101, 192.168.2.102,192.168.2.163, and three shards are replica set, and the 192.168.2.102 is a Arbiters</p>
  
  <p>the Config:
  A. <strong>192.168.2.101</strong></p>
  
  <pre><code>XXXX@ubuntu:~$ ps aux | grep mongo
  root     22651  0.2  2.5 899768 46944 ?        Sl   12:35   0:10 mongod -shardsvr -replSet shardA -port 27017 -dbpath /var/lib/mongodb/shardA1 -oplogSize 100 -logpath /var/log/mongodb/shardA1.log -logappend -fork
  root     22710  0.2  2.5 236084 47512 ?        Sl   12:35   0:08 mongod -configsvr -dbpath /var/lib/mongodb/config -port 20000 -logpath /var/log/mongodb/config.log -logappend -fork
  </code></pre>
  
  <p>B. <strong>192.168.2.102</strong></p>
  
  <pre><code>XXXXX@ubuntu:~$ ps aux | grep mongo
  root     10556  0.2  1.0 262468 38688 ?        Sl   13:07   0:04 mongod -shardsvr -replSet shardA -port 27017 -dbpath /var/lib/mongodb/shardA3 -oplogSize 100 -logpath /var/log/mongodb/shardA3.log -journal -logappend -fork
  root     10583  0.2  0.5 113940 21848 ?        Sl   13:07   0:03 mongod -configsvr -dbpath /var/lib/mongodb/config -port 20000 -logpath /var/log/mongodb/config.log -logappend -fork
  </code></pre>
  
  <p>C. <strong>192.168.2.163</strong></p>
  
  <pre><code>XXXXX@ubuntu:~$ ps aux | grep mongo
  root      5594  0.3  0.7 804604 30952 ?        Sl   10:45   0:21 mongod -shardsvr -replSet shardA -port 27017 -dbpath /var/lib/mongodb/shardA2 -oplogSize 100 -logpath /var/log/mongodb/shardA2.log -logappend -fork
  root      5650  0.2  0.7 134652 29456 ?        Sl   10:45   0:19 mongod -configsvr -dbpath /var/lib/mongodb/config -port 20000 -logpath /var/log/mongodb/config.log -logappend -fork
  </code></pre>
  
  <p>I start mongos on server <strong>192.168.2.102</strong>, but start failed</p>
  
  <p>the command is :</p>
  
  <pre><code>sudo mongos -configdb 192.168.2.101:20000,192.168.2.163:20000,192.168.2.102:20000 -port 30000 -chunkSize 256 -logpath $LOGPATH/mongos.log -logappend -fork
  </code></pre>
  
  <p>the log output is:</p>
  
  <pre><code>   XXXXX@ubuntu:~$ cat  /var/log/mongodb/mongos.log
      Tue Mar 19 13:10:16 [mongosMain] MongoS version 2.2.3 starting: pid=10666 port=30000 32-bit host=ubuntu (--help for usage)
      Tue Mar 19 13:10:16 [mongosMain] git version: f570771a5d8a3846eb7586eaffcf4c2f4a96bf08
      Tue Mar 19 13:10:16 [mongosMain] build info: Linux bs-linux32.10gen.cc 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_49
      Tue Mar 19 13:10:16 [mongosMain] options: { chunkSize: 256, configdb: "192.168.2.101:20000,192.168.2.163:20000,192.168.2.102:20000", fork: true, logappend: true, logpath: "/var/log/mongodb/mongos.log", port: 30000 }
      Tue Mar 19 13:10:16 [mongosMain] ERROR: config servers 192.168.2.101:20000 and 192.168.2.163:20000 differ config servers 192.168.2.101:20000 and 192.168.2.163:20000 differ config servers 192.168.2.101:20000 and 192.168.2.163:20000 differ config servers 192.168.2.101:20000 and 192.168.2.163:20000 differ config servers not in sync! config servers 192.168.2.101:20000 and 192.168.2.163:20000 differ
      chunks: "d41d8cd98f00b204e9800998ecf8427e"  EOO
      databases: "0195c739c938fdafd9632279694ea64e"   EOO
      Tue Mar 19 13:10:16 [mongosMain] configServer connection startup check failed
  </code></pre>
  
  <p>The error info is: config servers 192.168.2.101:20000 and 192.168.2.163:20000 differ, what's meaing?</p>
  
  <p>Thanks !</p>