Hello everyone, At present time, %d{ISO8601} is equivalent to writing %d{"yyyy-MM-dd HH:mm:ss,SSS"}. However, to match the ISO8601 standard the output should be that of %d{"yyyy-MM-dd'T'HH:mm:ss,SSS"}. Note the 'T' in the middle. On the other hand, there is also a necessity to maintain backward compatibility for log parsers that rely on the current albeit incorrect format. Thus, we are hesitating between two options Option 1) Introduce the constant ISO8601_OLD so that %d{ISO8601_OLD} is interpreted as equivalent to %d{"yyyy-MM-dd HH:mm:ss,SSS"} and *change* %d{ISO8601} so it is now equivalent to %d{"yyyy-MM-dd HH:mm:ss,SSS"}. Option 2) Keep %d{ISO8601} as equivalent to %d{"yyyy-MM-dd HH:mm:ss,SSS"} and *introduce* new constant ISO8601_STRICT so that %d{ISO8601_STRICT} is interpreted as equivalent to %d{"yyyy-MM-dd'T'HH:mm:ss,SSS"}. Personally, I favor the latter (option 2) as it preserves backward compatibility and allows users to easily refer to the correct ISO8601 format if they wish to do so. Indeed, writing %d{ISO8601_STRICT} is easier than %d{"yyyy-MM-dd'T'HH:mm:ss,SSS"}. Moreover, we can encourage the use of %d{ISO8601_STRICT} by favoring it in the documentation, e.g. by mentioning it more often. Note that writing just %d is equivalent to writing %d{ISO8601}. Thus, we can assume that for most user the output generated by %d is done using the default, i.e. the incorrect format, making the backward compatibility argument more potent. Cheers, -- Ceki On 6/17/2014 4:22, Tony Trinh wrote:
Per LOGBACK-262 [1], logback does not conform to ISO8601 when printing %d{ISO8601}. We're in the process of fixing this [2], but we'd like to maintain backward compatibility for log parsers that might rely on the incorrect format. We have a couple options.
OPTION 1. Add a new option for %d that enables the legacy incorrect format. Deprecate it, and remove it after several releases. Examples:
%d{ISO8601_OLD} %d{NOT8601} %d{OLD8601} %d{ISO8601,,old} other?
OPTION 2. Force users to specify a custom date format that matches the legacy incorrect format:
%d{"yyyy-MM-dd HH:mm:ss,SSS"}
Please provide feedback on these options (or a new one) by June 23.
Thanks, Tony
[1] http://jira.qos.ch/browse/LOGBACK-262 [2] https://github.com/qos-ch/logback/pull/207