## Collection on all mongod Instances 

local. startup_log 

On startup, each mongod instance inserts a document into startup_log (page 653) with diagnostic informa- tion about the mongod instance itself and host information. startup_log (page 653) is a capped collection. This information is primarily useful for diagnostic purposes. 

Example 

Consider the following prototype of a document from the startup_log (page 653) collection: 

{ "_id" : "<string>", "hostname" : "<string>", "startTime" : ISODate("<date>"), "startTimeLocal" : "<string>", "cmdLine" : { "dbpath" : "<path>", "<option>" : <value> }, "pid" : <number>, "buildinfo" : { "version" : "<string>", "gitVersion" : "<string>", "sysInfo" : "<string>", "loaderFlags" : "<string>", "compilerFlags" : "<string>", "allocator" : "<string>", "versionArray" : [ <num>, <num>, <...> ], "javascriptEngine" : "<string>", "bits" : <number>, "debug" : < boolean >, "maxBsonObjectSize" : <number> } } 

Documents in the startup_log (page 653) collection contain the following fields: 

local.startup_log. _id 

Includes the system hostname and a millisecond epoch value. 

local.startup_log. hostname 

The system’s hostname. 

local.startup_log. startTime 

A UTC ISODate value that reflects when the server started. 

local.startup_log. startTimeLocal 

A string that reports the startTime (page 653) in the system’s local time zone. 

local.startup_log. cmdLine 

An embedded document that reports the mongod runtime options and their values. 

local.startup_log. pid 

The process identifier for this process. 

local.startup_log. buildinfo 

An embedded document that reports information about the build environment and settings used to compile this mongod . This is the same output as buildInfo . See buildInfo . 

