getLog
定义
getLoggetLogis an administrative command that returns the most recent 1024 loggedmongodevents.getLogdoes not read log data from themongodlog file. It instead reads data from a RAM cache of loggedmongodevents. To rungetLog, use thedb.adminCommand()method.getLogreturns log data in escaped Relaxed Extended JSON v2.0 format. Previously, log data was returned as plaintext.
兼容性
此命令可用于以下环境中托管的部署：
MongoDB Atlas：用于云中 MongoDB 部署的完全托管服务
注意
所有 MongoDB Atlas 集群都支持此命令。有关 Atlas 对所有命令的支持的信息，请参阅不支持的命令。
MongoDB Enterprise：基于订阅、自我管理的 MongoDB 版本
MongoDB Community：源代码可用、免费使用且可自行管理的 MongoDB 版本
语法
该命令具有以下语法：
db.adminCommand( { getLog: <value> } )
命令字段
The possible values for getLog are:
值 | 说明 |
|---|---|
| Returns a list of the available values to the
|
| Returns the combined output of all recent log entries. |
| Returns log entries that may contain errors or warnings
from MongoDB's log from when the current process started. If
|
输出
If specified *, then the command returns a document with the
names of the other acceptable values.
Otherwise, the command returns a document that includes the following fields:
totalLinesWrittenfield that contains the number of log eventslogfield that contains an array of log eventsA
db.adminCommand()response document, containing status and timestamp information.
行为
Line Truncation
getLog truncates any event that contains more than 1024 characters.
Character Escaping
getLog returns log data in escaped Relaxed Extended JSON v2.0 format, using the following escape sequences
to render log output as valid JSON:
所代表的字符 | 转义序列 |
|---|---|
引号 ( |
|
Backslash ( |
|
退格 ( |
|
进纸 ( |
|
换行符 ( |
|
回车 ( |
|
Horizontal tab ( |
|
上面未列出的控制字符使用 \uXXXX 进行转义，其中 "XXXX" 是十六进制的 unicode 代码点。具有无效 UTF-8 编码的字节将替换为 \ufffd 表示的 unicode 替换字符。
Filtering
Within mongosh
getLog output can be filtered to make results more
readable or to match on specific criteria.
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:
db.adminCommand( { getLog:'global'} ).log.forEach(x => {print(x)})
This operation presents getLog output in the same format as
the MongoDB log file.
Outside mongosh with jq
在使用 MongoDB 结构化日志时，您可以使用第三方 jq 命令行实用程序 来轻松美观地打印日志条目，并提供强大的基于键的匹配和过滤功能。
jq是一个开源JSON解析器，适用于Linux、 Windows和 macOS 。
To use jq with getLog output, you must use the
--eval option to mongosh.
The following operation uses jq to filter on the REPL
component to present only those log
messages associated with replication:
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。
See 解析结构化日志消息 for more examples of filtering log output
using jq. The jq syntax presented in each linked example can be
used with the above mongo --eval operation with minor adjustment.
For example, the following syntax adapts the linked "Counting Unique
Messages" example for use with getLog:
mongosh --quiet --eval "db.adminCommand( { getLog:'global'} ).log.forEach(x => {print(x)})" | jq -r ".msg" | sort | uniq -c | sort -rn | head -10
示例
Retrieve Available Log Filters
The following operation, run from mongosh,
returns the available log filters for passing to getLog:
db.adminCommand( { getLog: "*" } )
该操作将返回以下文档：
{ "names" : [ "global", "startupWarnings" ], "ok" : 1 }
Retrieve Recent Events from Log
The following operation, run from mongosh,
retrieves the most recent global events for the
mongod:
db.adminCommand( { getLog : "global" } )
The operation returns a document similar to the following:
{ "totalLinesWritten" : <num>, "log" : [ "{\"t\":{\"$date\":\"2020-05-19T19:10:48.871+00:00\"},\"s\":\"I\", \"C\":\"STORAGE\", \"id\":4615611, \"ctx\":\"initandlisten\",\"msg\":\"MongoDB starting\",\"attr\":{\"pid\":12345,\"端口\":27001,\"dbPath\":\"/var/lib/mongo\",\"architecture\":\"64-bit\",\"host\":\"server1.example.com\"}}", "{\"t\":{\"$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\":{\"选项\":{\"config\":\"/etc/mongod.conf\",\"net\":{\"bindIp\":\"127.0.0.1\",\"端口\":27001},\"processManagement\":{\"fork\":true,\"timeZoneInfo\":\"/usr/share/zoneinfo\"},\"复制\":{\"replSetName\":\"repl-shard1\"},\"分片\":{\"clusterRole\":\"shardsvr\"},\"storage\":{\"dbPath\":\"/var/lib/mongo\",\"journal\":{\"enabled\":true},\"WiredTiger\":{\"engineConfig\":{\"cacheSizeGB\":0.1}}},\"systemLog\":{\"destination\":\"file\",\"logAppend\":true,\"路径\":\"/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\":{\"$date\":\"2020-05-19T19:15:10.393+00:00\"},\"s\":\"I\", \"C\":\"NETWORK\", \"id\":51800, \"ctx\":\"conn67\",\"msg\":\"client metadata\",\"attr\":{\"remote\":\"127.0.0.1:35724\",\"客户端\":\"conn67\",\"doc\":{\"application\":{\"名称\":\"MongoDB Shell\"},\"驱动\":{\"名称\":\"MongoDB Internal Client\",\"version\":\"4.4.0\"},\"os\":{\"类型\":\"Linux\",\"名称\":\"CentOS Linux release 8.0.1905 (Core) \",\"architecture\":\"x86_64\",\"version\":\"Kernel 4.18.0-80.11.2.el8_0.x86_64\"}}}}" ], "ok" : 1, "$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>) }