getLog

~~On this page~~本页内容

~~Syntax~~语法
~~Behavior~~行为
~~Filtering~~筛选
~~Examples~~示例

getLog

getLog ~~is an administrative command that returns the most recent 1024 logged mongod events.~~ 是一个管理命令，它返回最近1024个记录的mongod事件。getLog does not read log data from the mongod log file. 不从mongod日志文件读取日志数据。~~It instead reads data from a RAM cache of logged mongod events.~~ 相反，它从记录的mongod事件的RAM缓存中读取数据。~~To run getLog, use the db.adminCommand() method.~~要运行getLog，请使用db.adminCommand()方法。

~~Starting in MongoDB 4.4, getLog returns log data in escaped Relaxed Extended JSON v2.0 format.~~ 从MongoDB 4.4开始，getLog以转义的Relaxed Extended JSON v2.0格式返回日志数据。~~Previously, log data was returned as plaintext.~~以前，日志数据以明文形式返回。

Syntax语法

~~The getLog command has the following syntax:~~getLog命令具有以下语法：

db.adminCommand( { getLog: <value> } )

Command Fields命令字段

~~The possible values for getLog are:~~getLog的可能值为：

~~Value~~值	~~Description~~描述
`*`	~~Returns a list of the available values to the `getLog` command.~~ 向`getLog`命令返回可用值的列表。
`global`	~~Returns the combined output of all recent log entries.~~返回所有最近日志项的组合输出。
`startupWarnings`	~~Returns log entries that may contain errors or warnings from MongoDB's log from when the current process started.~~ 返回当前进程启动时MongoDB日志中可能包含错误或警告的日志条目。~~If `mongod` started without warnings, this filter may return an empty array.~~ 如果`mongod`在没有警告的情况下启动，此筛选器可能会返回一个空数组。

Output

~~If specified *, then the command returns a document with the names of the other acceptable values.~~如果指定了*，则该命令将返回包含其他可接受值名称的文档。

~~Otherwise, the command returns a document that includes the following fields:~~否则，该命令将返回包含以下字段的文档：

~~totalLinesWritten field that contains the number of log events~~包含日志事件数的totalLinesWritten字段
~~log field that contains an array of log events~~包含日志事件数组的log字段
~~A db.adminCommand() response document, containing status and timestamp information.~~db.adminCommand()响应文档，包含状态和时间戳信息。

Behavior行为

Line Truncation线路截断

~~Starting in MongoDB 4.2, getLog truncates any event that contains more than 1024 characters.~~ 从MongoDB 4.2开始，getLog会截断任何包含1024个以上字符的事件。~~In earlier versions, getLog truncates after 512 characters.~~在早期版本中，getLog在512个字符后截断。

Character Escaping字符转义

~~Starting in MongoDB 4.4, getLog returns log data in escaped Relaxed Extended JSON v2.0 format, using the following escape sequences to render log output as valid JSON:~~从MongoDB 4.4开始，getLog以转义的Relaxed Extended JSON v2.0格式返回日志数据，使用以下转义序列将日志输出呈现为有效的JSON：

~~Character Represented~~表示的字符	~~Escape Sequence~~Escape序列
Quotation Mark (`"`)	`\"`
Backslash (`\`)	`\\`
Backspace (`0x08`)	`\b`
Formfeed (`0x0C`)	`\f`
Newline (`0x0A`)	`\n`
Carriage return (`0x0D`)	`\r`
Horizontal tab (`0x09`)	`\t`

~~Control characters not listed above are escaped with \uXXXX where "XXXX" is the unicode codepoint in hexadecimal.~~ 上面未列出的控制字符用\uXXXX转义，其中“XXXX”是十六进制的unicode代码点。~~Bytes with invalid UTF-8 encoding are replaced with the unicode replacement character represented by \ufffd.~~UTF-8编码无效的字节将替换为\ufffd表示的unicode替换字符。

Filtering筛选

Within `mongosh``mongosh`内部

~~getLog output can be filtered to make results more readable or to match on specific criteria.~~可以对getLog输出进行筛选，以使结果更可读或符合特定条件。

~~The following operation prints just the log field (which contains the array of all recent log events), and removes character escaping from each log message:~~以下操作仅打印log字段（包含所有最近日志事件的数组），并从每个日志消息中删除字符转义：

db.adminCommand( { getLog:'global'} ).log.forEach(x => {print(x)})

~~This operation presents getLog output in the same format as the MongoDB log file.~~此操作以与MongoDBlog file相同的格式显示getLog输出。

~~Note~~注意

~~getLog only shows the most recent 1024 logged mongod events, and is not a replacement for the MongoDB log file.~~getLog仅显示最近1024个已记录的mongod事件，不能替代MongoDBlog file。

Outside `mongosh` with `jq``mongosh`和`jq`外部

When working with MongoDB structured logging, the third-party jq command-line utility is a useful tool that allows for easy pretty-printing of log entries, and powerful key-based matching and filtering.在使用MongoDB结构化日志记录时，第三方jq命令行实用程序是一个有用的工具，它允许轻松漂亮地打印日志条目，以及强大的基于键的匹配和筛选。

jq ~~is an open-source JSON parser, and is available for Linux, Windows, and macOS.~~是一个开源JSON解析器，可用于Linux、Windows和macOS。

~~To use jq with getLog output, you must use the --eval option to mongosh.~~ 要在getLog输出中使用jq，必须对mongosh使用--eval选项。~~The following operation uses jq to filter on the REPLcomponent to present only those log messages associated with replication:~~以下操作使用jq对REPL组件进行筛选，以仅显示与复制相关的日志消息：

mongosh --quiet --eval "db.adminCommand( { getLog:'global'} ).log.forEach(x => {print(x)})" | jq -c '. | select(.c=="REPL")'

~~Be sure to provide any necessary connection-specific parameters to mongosh as needed, such as --host or --port.~~确保根据需要向mongosh提供任何必要的连接特定参数，例如--host或--port。

~~See Parsing Structured Log Messages for more examples of filtering log output using jq.~~ 有关使用jq筛选日志输出的更多示例，请参阅解析结构化日志消息。~~The jq syntax presented in each linked example can be used with the above mongo --eval operation with minor adjustment.~~ 每个链接示例中提供的jq语法都可以与上面的mongo --eval操作一起使用，只需稍作调整。~~For example, the following syntax adapts the linked "Counting Unique Messages" example for use with getLog:~~例如，以下语法调整了链接的“计数唯一消息”示例，以便与getLog一起使用：

mongosh --quiet --eval "db.adminCommand( { getLog:'global'} ).log.forEach(x => {print(x)})" | jq -r ".msg" | sort | uniq -c | sort -rn | head -10

Examples示例

Retrieve Available Log Filters检索可用日志筛选器

~~The following operation, run from mongosh, returns the available log filters for passing to getLog:~~从mongosh运行的以下操作将返回可用的日志筛选器以传递给getLog：

db.adminCommand( { getLog: "*" } )

~~The operation returns the following document:~~该操作返回以下文档：

{ "names" : [ "global", "startupWarnings" ], "ok" : 1 }

Retrieve Recent Events from Log从日志中检索最近的事件

~~The following operation, run from mongosh, retrieves the most recent global events for the mongod:~~以下操作从mongosh运行，检索mongod的最新global事件：

db.adminCommand( { getLog : "global" } )

~~The operation returns a document similar to the following:~~该操作返回一个类似于以下内容的文档：

{
      "totalLinesWritten" : <num>,
      "log" : [
              "{\"t\":{\"$date\":\"2020-05-19T19:10:48.871+00:00\"},\"s\":\"I\",  \"c\":\"STORAGE\",  \"id\":4615611, \"ctx\":\"initandlisten\",\"msg\":\"MongoDB starting\",\"attr\":{\"pid\":12345,\"port\":27001,\"dbPath\":\"/var/lib/mongo\",\"architecture\":\"64-bit\",\"host\":\"server1.example.com\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:48.871+00:00\"},\"s\":\"I\",  \"c\":\"CONTROL\",  \"id\":23403,   \"ctx\":\"initandlisten\",\"msg\":\"Build Info\",\"attr\":{\"buildInfo\":{\"version\":\"4.4.0\",\"gitVersion\":\"328c35e4b883540675fb4b626c53a08f74e43cf0\",\"openSSLVersion\":\"OpenSSL 1.1.1c FIPS  28 May 2019\",\"modules\":[],\"allocator\":\"tcmalloc\",\"environment\":{\"distmod\":\"rhel80\",\"distarch\":\"x86_64\",\"target_arch\":\"x86_64\"}}}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:48.871+00:00\"},\"s\":\"I\",  \"c\":\"CONTROL\",  \"id\":51765,   \"ctx\":\"initandlisten\",\"msg\":\"Operating System\",\"attr\":{\"os\":{\"name\":\"CentOS Linux release 8.0.1905 (Core) \",\"version\":\"Kernel 4.18.0-80.11.2.el8_0.x86_64\"}}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:48.871+00:00\"},\"s\":\"I\",  \"c\":\"CONTROL\",  \"id\":21951,   \"ctx\":\"initandlisten\",\"msg\":\"Options set by command line\",\"attr\":{\"options\":{\"config\":\"/etc/mongod.conf\",\"net\":{\"bindIp\":\"127.0.0.1\",\"port\":27001},\"processManagement\":{\"fork\":true,\"timeZoneInfo\":\"/usr/share/zoneinfo\"},\"replication\":{\"replSetName\":\"repl-shard1\"},\"sharding\":{\"clusterRole\":\"shardsvr\"},\"storage\":{\"dbPath\":\"/var/lib/mongo\",\"journal\":{\"enabled\":true},\"wiredTiger\":{\"engineConfig\":{\"cacheSizeGB\":0.1}}},\"systemLog\":{\"destination\":\"file\",\"logAppend\":true,\"path\":\"/var/log/mongodb/mongod.log\"}}}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:48.873+00:00\"},\"s\":\"I\",  \"c\":\"STORAGE\",  \"id\":22270,   \"ctx\":\"initandlisten\",\"msg\":\"Storage engine to use detected by data files\",\"attr\":{\"dbpath\":\"/var/lib/mongo\",\"storageEngine\":\"wiredTiger\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:48.873+00:00\"},\"s\":\"I\",  \"c\":\"STORAGE\",  \"id\":22315,   \"ctx\":\"initandlisten\",\"msg\":\"wiredtiger_open config\",\"attr\":{\"config\":\"create,cache_size=102M,session_max=33000,eviction=(threads_min=4,threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000,close_scan_interval=10,close_handle_minimum=250),statistics_log=(wait=0),verbose=[recovery_progress,checkpoint_progress,compact_progress],\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"CONNPOOL\", \"id\":22576,   \"ctx\":\"ReplicaSetMonitor-TaskExecutor\",\"msg\":\"Connecting\",\"attr\":{\"hostAndPort\":\"server1.example.com:27001\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"CONNPOOL\", \"id\":22576,   \"ctx\":\"ReplicaSetMonitor-TaskExecutor\",\"msg\":\"Connecting\",\"attr\":{\"hostAndPort\":\"server2.example.com:27001\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"CONNPOOL\", \"id\":22576,   \"ctx\":\"ReplicaSetMonitor-TaskExecutor\",\"msg\":\"Connecting\",\"attr\":{\"hostAndPort\":\"server3.example.com:27001\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"CONNPOOL\", \"id\":22576,   \"ctx\":\"ReplicaSetMonitor-TaskExecutor\",\"msg\":\"Connecting\",\"attr\":{\"hostAndPort\":\"server4.example.com:27001\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"CONNPOOL\", \"id\":22576,   \"ctx\":\"ReplicaSetMonitor-TaskExecutor\",\"msg\":\"Connecting\",\"attr\":{\"hostAndPort\":\"server5.example.com:27001\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"CONNPOOL\", \"id\":22576,   \"ctx\":\"ReplicaSetMonitor-TaskExecutor\",\"msg\":\"Connecting\",\"attr\":{\"hostAndPort\":\"server6.example.com:27001\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"NETWORK\",  \"id\":23015,   \"ctx\":\"listener\",\"msg\":\"Listening on\",\"attr\":{\"address\":\"/tmp/mongodb-27001.sock\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"NETWORK\",  \"id\":23015,   \"ctx\":\"listener\",\"msg\":\"Listening on\",\"attr\":{\"address\":\"127.0.0.1\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:10:58.877+00:00\"},\"s\":\"I\",  \"c\":\"NETWORK\",  \"id\":23016,   \"ctx\":\"listener\",\"msg\":\"Waiting for connections\",\"attr\":{\"port\":27001,\"ssl\":\"off\"}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:15:10.392+00:00\"},\"s\":\"I\",  \"c\":\"NETWORK\",  \"id\":22943,   \"ctx\":\"listener\",\"msg\":\"connection accepted\",\"attr\":{\"remote\":\"127.0.0.1:35724\",\"sessionId\":67,\"connectionCount\":30}}",
              "{\"t\":{\"$date\":\"2020-05-19T19:15:10.393+00:00\"},\"s\":\"I\",  \"c\":\"NETWORK\",  \"id\":51800,   \"ctx\":\"conn67\",\"msg\":\"client metadata\",\"attr\":{\"remote\":\"127.0.0.1:35724\",\"client\":\"conn67\",\"doc\":{\"application\":{\"name\":\"MongoDB Shell\"},\"driver\":{\"name\":\"MongoDB Internal Client\",\"version\":\"4.4.0\"},\"os\":{\"type\":\"Linux\",\"name\":\"CentOS Linux release 8.0.1905 (Core) \",\"architecture\":\"x86_64\",\"version\":\"Kernel 4.18.0-80.11.2.el8_0.x86_64\"}}}}"
      ],
      "ok" : 1,
      "$gleStats" : {
              "lastOpTime" : Timestamp(<ts>),
              "electionId" : ObjectId(<id>)
      },
      "lastCommittedOpTime" : Timestamp(<ts>),
      "$configServerState" : {
              "opTime" : {
                      "ts" : Timestamp(<ts>),
                      "t" : NumberLong(8)
               }
      },
      "$clusterTime" : {
              "clusterTime" : Timestamp(<ts>),
              "signature" : {
                      "hash" : BinData(<bin>),
                      "keyId" : NumberLong(0)
               }
      },
      "operationTime" : Timestamp(<ts>)
}

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