Hi Jochen, I'm sorry that you had trouble with the cron documentation. Under the covers we use Quartz to handle the cron scheduling. You can find a more in-depth description of the cron string in their documentation. [1]
Year is an optional field and seems to be absent from the default. 1 is Sunday. The question mark is a placeholder. I've written up an issue to correct our documentation. [2] Thanks, Bryan [1] http://www.quartz-scheduler.org/documentation/quartz-2.x/tutorials/crontrigger.html [2] https://issues.apache.org/jira/browse/NIFI-3391 On Tue, Jan 24, 2017 at 11:37 AM, Jochen Van Den Bossche < [email protected]> wrote: > My first contact with NiFi was not a good one. When reviewing what one of > my more experienced colleagues had set up, I came across a tiny UI bug and > 2 mistakes in the documentation. In just 15 minutes. > > Tiny UI bug: > Open the [Process Details] of a Process with [Scheduling Strategy] = "CRON > driven" (or make one). > In the [Run Schedule] field is a crontab string. Since there was one field > more then what I was used to, I hoped to get an explanation of that field > by hovering over the little question mark. > But the text that pops up is: "The minimum number of seconds that should > elapse between task executions" > This is clearly incorrect. > > 2 mistakes in the Documentation: > To find an answer to my "Why 6 fields?" question I Googled and thus landed > on https://nifi.apache.org/docs/nifi-docs/html/user-guide. > html#Configuring_a_Processor. > There I saw "six fields" and (bulleted list) that there is also a field > for seconds. Question answered. OK. > > But then I reread the entire passage attentively: > This value is made up of six fields, each separated by a > space. These fields include: > > * Seconds > > * Minutes > > * Hours > > * Day of Month > > * Month > > * Day of Week > > * Year > There are seven bullets there. > A bit lower is a paragraph that explains the day-of-week numbering and the > L appendix: > For the Day of Week field, valid values are 1 (Sunday) through 7 > (Saturday). Additionally, a value of L may be appended to one of these > values to indicate the last occurrence of this day in the month. For > example, 1L can be used to indicate the last Monday of the month. > So Is 1 Sunday or Monday???? > > Also my colleague set the Run Schedule to > 0 0 9 * * ? > and apparently that works. > What is the meaning of the question mark? > >
