==== Logs ==== Swift has quite verbose logging, and the generated logs can be used for cluster monitoring, utilization calculations, audit records, and more. As an overview, Swift's logs are sent to syslog and organized by log level and syslog facility. All log lines related to the same request have the same transaction id. This page documents the log formats used in the system. .. note:: By default, Swift will log full log lines. However, with the ``log_max_line_length`` setting and depending on your logging server software, lines may be truncated or shortened. With ``log_max_line_length < 7``, the log line will be truncated. With ``log_max_line_length >= 7``, the log line will be "shortened": about half the max length followed by " ... " followed by the other half the max length. Unless you use exceptionally short values, you are unlikely to run across this with the following documented log lines, but you may see it with debugging and error log lines. ---------- Proxy Logs ---------- The proxy logs contain the record of all external API requests made to the proxy server. Swift's proxy servers log requests using a custom format designed to provide robust information and simple processing. The log format is:: client_ip remote_addr datetime request_method request_path protocol status_int referer user_agent auth_token bytes_recvd bytes_sent client_etag transaction_id headers request_time source log_info request_start_time request_end_time =================== ========================================================== **Log Field** **Value** ------------------- ---------------------------------------------------------- client_ip Swift's guess at the end-client IP, taken from various headers in the request. remote_addr The IP address of the other end of the TCP connection. datetime Timestamp of the request, in day/month/year/hour/minute/second format. request_method The HTTP verb in the request. request_path The path portion of the request. protocol The transport protocol used (currently one of http or https). status_int The response code for the request. referer The value of the HTTP Referer header. user_agent The value of the HTTP User-Agent header. auth_token The value of the auth token. This may be truncated or otherwise obscured. bytes_recvd The number of bytes read from the client for this request. bytes_sent The number of bytes sent to the client in the body of the response. This is how many bytes were yielded to the WSGI server. client_etag The etag header value given by the client. transaction_id The transaction id of the request. headers The headers given in the request. request_time The duration of the request. source The "source" of the reuqest. This may be set for requests that are generated in order to fulfill client requests, e.g. bulk uploads. log_info Various info that may be useful for diagnostics, e.g. the value of any x-delete-at header. request_start_time High-resolution timestamp from the start of the request. request_end_time High-resolution timestamp from the end of the request. =================== ========================================================== In one log line, all of the above fields are space-separated and url-encoded. If any value is empty, it will be logged as a "-". This allows for simple parsing by splitting each line on whitespace. New values may be placed at the end of the log line from time to time, but the order of the existing values will not change. Swift log processing utilities should look for the first N fields they require (e.g. in Python using something like ``log_line.split()[:14]`` to get up through the transaction id). Swift Source ============ The ``source`` value in the proxy logs is used to identify the originator of a request in the system. For example, if the client initiates a bulk upload, the proxy server may end up doing many requests. The initial bulk upload request will be logged as normal, but all of the internal "child requests" will have a source value indicating they came from the bulk functionality. ======================= ============================= **Logged Source Value** **Originator of the Request** ----------------------- ----------------------------- FP :ref:`formpost` SLO :ref:`static-large-objects` SW :ref:`staticweb` TU :ref:`tempurl` BD :ref:`bulk` (delete) EA :ref:`bulk` (extract) CQ :ref:`container-quotas` CS :ref:`container-sync` TA :ref:`common_tempauth` DLO :ref:`dynamic-large-objects` ======================= ============================= ----------------- Storage Node Logs ----------------- Swift's account, container, and object server processes each log requests that they receive, if they have been configured to do so with the ``log_requests`` config parameter (which defaults to true). The format for these log lines is:: remote_addr - - [datetime] "request_method request_path" status_int content_length "referer" "transaction_id" "user_agent" request_time additional_info =================== ========================================================== **Log Field** **Value** ------------------- ---------------------------------------------------------- remote_addr The IP address of the other end of the TCP connection. datetime Timestamp of the request, in "day/month/year:hour:minute:second +0000" format. request_method The HTTP verb in the request. request_path The path portion of the request. status_int The response code for the request. content_length The value of the Content-Length header in the response. referer The value of the HTTP Referer header. transaction_id The transaction id of the request. user_agent The value of the HTTP User-Agent header. Swift's proxy server sets its user-agent to ``"proxy-server ".`` request_time The duration of the request. additional_info Additional useful information. =================== ==========================================================