Logging Overview

You can enable logging to facilitate analysis or audit as required. Access logs enable a bucket owner to analyze the property, type, or trend of requests to the bucket in depth. When the logging function of a bucket is enabled, OBS will log access requests for the bucket automatically, and write the generated log files to the specified bucket (target bucket).

After logging is enabled, the log delivery user group will be automatically granted the permission to read the bucket ACL and write the bucket where logs are saved. If you manually disable such permissions, bucket logging fails.

OBS can record bucket access requests in logs for request analysis and log audit.

Logs occupy the OBS storage that incurs costs, so OBS does not collect bucket access logs by default.

After logging is configured, you can view operation logs in the bucket that stores the logs in approximately fifteen minutes.

The following shows an example access log of the target bucket:

787f2f92b20943998a4fe2ab75eb09b8 bucket [13/Aug/2015:01:43:42 +0000] xx.xx.xx.xx 
787f2f92b20943998a4fe2ab75eb09b8 281599BACAD9376ECE141B842B94535B  REST.GET.BUCKET.LOCATION 
- "GET /bucket?location HTTP/1.1" 200 - 211 - 6 6 "-"  "HttpClient" - -

The access log of each bucket contains the following information.

**Table 1** Bucket log format
Parameter	Value Example	Description
BucketOwner	787f2f92b20943998a4fe2ab75eb09b8	Account ID of the bucket owner
Bucket	bucket	Name of the bucket
Time	[13/Aug/2015:01:43:42 +0000]	Timestamp of the request (UTC)
Remote IP	xx.xx.xx.xx	IP address from where the request is initiated
Requester	787f2f92b20943998a4fe2ab75eb09b8	Requester ID
RequestID	281599BACAD9376ECE141B842B94535B	Request ID
Operation	REST.GET.BUCKET.LOCATION	Name of the operation
Key	-	Object name
Request-URI	GET /bucket?location HTTP/1.1	URI of the request
HTTPStatus	200	Return code
ErrorCode	-	Error code
BytesSent	211	Size of the HTTP response, expressed in bytes
ObjectSize	-	Object size (bytes)
TotalTime	6	Processing time on the server (ms)
Turn-AroundTime	6	Total time for processing the request (ms)
Referer	-	Header field Referer of the request
User-Agent	HttpClient	User-Agent header of the request
VersionID	-	Version ID carried in the request
STSLogUrn	-	Federated authentication and agency information
StorageClass	STANDARD_IA	Current storage class of the object
TargetStorageClass	GLACIER	Storage class that the object will be transited to