mongotemplate 连表条件查询 mongodb连接数查询

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mob6454cc64e36b 2024-05-24 17:42:34

文章标签 linux mongodb 连接数 文章分类 机器学习人工智能

在Linux平台下，无论是64位或者32位的MongoDB默认最大连接数都是819，WIN平台不知道，估计也没有人在 WIN平台下使用MongoDB做生产环境

[ 
 root@DELL113 mongodb-linux-i686-2.4.1 
 ]# mongo admin -u root -p password 
 
 MongoDB shell version: 2.4.1 
 
 connecting to: 192.168.6.42/admin 
 
 > db.serverStatus().connections 
 
 { "current" : 1, "available" : 818, "totalCreated" : NumberLong(1) }

途中available显示818少了一个，表示空闲的。current表示已经占用了的连接数，两数一加就等于819，如果我现在在连接一个，那么available就是817，current就是2

# 
  ./bin/mongo 192.168.6.42 
 
MongoDB shell version: 2.4.1 
 
 connecting to: 192.168.6.42/test 
 
 > db.serverStatus().connections 
 
 {  
 " 
 current 
 " : 1,  
 " 
 available 
 " : 818,  
 " 
 totalCreated 
 " : NumberLong(1) } 
 
 > db.serverStatus().connections 
 
 {  
 " 
 current 
 " : 2,  
 " 
 available 
 " : 817,  
 " 
 totalCreated 
 "

819个连接数对于一般的站点我认为已经够用，并且都是现连现取现断。但这个连接数也可以修改，只要在启动的时候加入--maxConns即可
服务器启动

# 
  ./bin/mongod --dbpath=/root/db --maxConns=2000 
 
Wed Apr 3 11:06:21.905 [initandlisten] MongoDB starting : pid=2812 port=27017 dbpath=/root/db 64-bit host=lee 
 
 Wed Apr 3 11:06:21.957 [initandlisten] db version v2.4.1 
 
 Wed Apr 3 11:06:21.957 [initandlisten] git version: 1560959e9ce11a693be8b4d0d160d633eee75110 
 
 Wed Apr 3 11:06:21.957 [initandlisten] build info: Linux ip-10-2-29-40 2.6.21.7-2.ec2.v1.2.fc8xen  
 # 
 1 SMP Fri Nov 20 17:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_49 
 
Wed Apr 3 11:06:21.957 [initandlisten] allocator: tcmalloc 
 
 Wed Apr 3 11:06:21.957 [initandlisten] options: { dbpath:  
 " 
 /root/db 
 ", maxConns: 2000 } 
 
 Wed Apr 3 11:06:21.982 [initandlisten] journal dir=/root/db/journal 
 
 Wed Apr 3 11:06:21.982 [initandlisten] recover : no journal files present, no recovery needed 
 
 Wed Apr 3 11:06:22.297 [initandlisten] preallocateIsFaster=true 2.62 
 
 Wed Apr 3 11:06:22.717 [initandlisten] --maxConns too high, can only handle 819 
 
 Wed Apr 3 11:06:22.724 [initandlisten] waiting  
 for connections on port 27017 
 
 Wed Apr 3 11:06:22.725 [websvr] admin web console waiting  
 for connections on port 28017 
 
 Wed Apr 3 11:06:25.126 [initandlisten] connection accepted  
 from 192.168.4.86:53917  
 # 
 1 (1 connection now open)

查询最大连接数

# 
  ./bin/mongo 192.168.6.42 
 
MongoDB shell version: 2.4.1 
 
 connecting to: 192.168.6.42/test 
 
 > db.serverStatus().connections 
 
 {  
 " 
 current 
 " : 1,  
 " 
 available 
 " : 818,  
 " 
 totalCreated 
 " : NumberLong(1) } 
 
 >

发现还是819？其实是Linux默认进程能打开最大文件数有关，可以通过ulimit 解决

# 
  ulimit -n 2500 
 
[root@lee mongodb-linux-x86_64-2.4.1] 
 # 
  ./bin/mongod --dbpath=/root/db --maxConns=2000 
 
Wed Apr 3 11:11:07.013 [initandlisten] MongoDB starting : pid=2930 port=27017 dbpath=/root/db 64-bit host=lee 
 
 Wed Apr 3 11:11:07.013 [initandlisten] db version v2.4.1 
 
 Wed Apr 3 11:11:07.013 [initandlisten] git version: 1560959e9ce11a693be8b4d0d160d633eee75110 
 
 Wed Apr 3 11:11:07.013 [initandlisten] build info: Linux ip-10-2-29-40 2.6.21.7-2.ec2.v1.2.fc8xen  
 # 
 1 SMP Fri Nov 20 17:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_49 
 
Wed Apr 3 11:11:07.013 [initandlisten] allocator: tcmalloc 
 
 Wed Apr 3 11:11:07.013 [initandlisten] options: { dbpath:  
 " 
 /root/db 
 ", maxConns: 2000 } 
 
 Wed Apr 3 11:11:07.031 [initandlisten] journal dir=/root/db/journal 
 
 Wed Apr 3 11:11:07.031 [initandlisten] recover : no journal files present, no recovery needed 
 
 Wed Apr 3 11:11:07.170 [initandlisten] waiting  
 for connections on port 27017 
 
 Wed Apr 3 11:11:07.171 [websvr] admin web console waiting  
 for connections on port 28017 
 
 Wed Apr 3 11:11:10.076 [initandlisten] connection accepted  
 from 192.168.4.86:53161  
 # 
 1 (1 connection now open)

再查看最大连接数，

# 
  ./bin/mongo 192.168.6.42 
 
MongoDB shell version: 2.4.1 
 
 connecting to: 192.168.6.42/test 
 
 > db.serverStatus().connections 
 
 {  
 " 
 current 
 " : 1,  
 " 
 available 
 " : 1999,  
 " 
 totalCreated 
 " : NumberLong(1) } 
 
 >

如果我们只是普通用户，只是暂时的修改ulimit -n，可以直接shell命令来修改（ulimit -n 1024000）。但是这个设置时暂时的保留！当我们退出bash后，该值恢复原值。
如果要永久修改ulimit，需要修改/etc/security/limits.conf。
vim /etc/security/limits.conf
# 添加如下两行