增加MongoDB的最大连接数

要增加MongoDB的最大连接数，需要修改MongoDB的配置文件，在mongod.conf中添加相关设置。在文件末尾添加以下配置项：

systemLog:
  destination: file
  path: /path/to/mongod.log
  logAppend: true
  quiet: false
  logRotate: reopen
  pathCheck: true

storage:
  dbPath: /path/to/data
  journal:
    enabled: true
  engine: wiredTiger
  wiredTigerJournalPreallocate: true
  wiredTigerEngineConfig:
    maxObjectSizeKb: 16777216
    minObjectSizeKb: 1000
    blockSizeKb: 4096
    cacheSizeKb: 1000
    indexEntrySizeKb: 250

net:
  bindIp: 127.0.0.1
  port: 27017
  protocolVersion: 3
  writeConcern: 1

然后，重新启动MongoDB服务以应用更改。可以通过在命令行中输入以下命令来检查MongoDB服务是否在运行：

sudo systemctl status mongodb

如果服务未运行，则可以使用以下命令启动MongoDB服务：

sudo systemctl start mongodb

最后，可以在MongoDB的命令行中使用以下命令检查最大连接数是否已更改：

db.runCommand({ connectionStatus: 1 })

如果最大连接数已更改，则命令输出将类似于以下内容：

{

"connections": {

"total": 1,

"successful": 1,

"failed": 0

},

"connectionsPerHost": {

"total": 1,

"successful": 1,

"failed": 0

},

"currentHost": "localhost:27017",

"failoverTimeout": 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000