Helping setting up cron-based nifi processor

[#1]

I'm trying to setup a nifi processor to run once daily, using the 'cron' option under scheduling.

Under "run schedule", I put "01 18 * * * ?" , which should be 6:01pm (I couldn't get nifi to accept it without the question mark).

But this causes the scheduler to run on the hour, every hour.

Can someone please help me with my syntax here?

[#2 · Accepted solution]

@Zack Riesland

The Cron you have there should run 18 minutes and 1 second into every hour.

What you really are looking for as a cron here for 6:01pm is ( 0 1 18 * * ? * or 0 1 18 * * ? )

• CRON driven: When using the CRON driven scheduling mode, the Processor is scheduled to run periodically, similar to the Timer driven scheduling mode. However, the CRON driven mode provides significantly more flexibility at the expense of increasing the complexity of the configuration. This value is made up of seven fields (where the seventh field is optional), each separated by a space. These fields include:
  • Seconds
  • Minutes
  • Hours
  • Day of Month
  • Month
  • Day of Week
  • Year

The value for each of these fields should be a number, range, or increment. Range here refers to a syntax of <number>-<number>. For example,the Seconds field could be set to 0-30, meaning that the Processor should only be scheduled if the time is 0 to 30 seconds after the minute. Additionally, a value of * indicates that all values are valid for this field. Multiple values can also be entered using a , as a separator: 0,5,10,15,30. An increment is written as <start value>/<increment>. For example, settings a value of 0/10 for the seconds fields means that valid values are 0, 10, 20, 30, 40, and 50. However, if we change this to 5/10, valid values become 5, 15, 25, 35, 45, and 55.

For the Month field, valid values are 1 (January) through 12 (December).

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.

Thanks,

Matt

[#3]

NiFi does not use a linux cron. It uses a Quartz cron/scheduler.

[#4]

When I enter "0 0 18 * * * ?", I get this error message: "Scheduling Period '0 0 18 * * * ?' is not a valid cron expression: '?' can only be specified for Day-of-Month or Day-of-Week"

However, "0 0 18 * * ? *" seems to work.

What is the difference between the meaning of "*" and "?" ?

[#5]

@Zack Riesland

There are seven fields; however, the seventh field is optional. So you are correct.

so both " 0 0 18 * * ? " and " 0 0 18 * * ? * " are valid.

The below is from http://www.quartz-scheduler.org/documentation/quartz-2.x/tutorials/crontrigger.html

----------------

• * (“all values”) - used to select all values within a field. For example, “” in the minute field means *“every minute”.
• ? (“no specific value”) - useful when you need to specify something in one of the two fields in which the character is allowed, but not the other. For example, if I want my trigger to fire on a particular day of the month (say, the 10th), but don’t care what day of the week that happens to be, I would put “10” in the day-of-month field, and “?” in the day-of-week field. See the examples below for clarification.

-----------------

so only fields 4 and 6 will accept ?.

Thanks,

Matt

[#6]

Hi @zack_riesland 

can you provide corn expression for this timing 12:00PM and 11:40AM 

[#7]

@hargav  
It is not possible to create single Quartz cron that will schedule at 12:00:00 PM and 11:40:00 AM each day.

However, the following would execute at 11:40:00AM and 12:40:00PM every day

0 40 11,12 * * ?

 
and following would execute at 11:00:00AM, 11:40:00AM, 12:00:00PM, and 12:40:00PM

0 0,40 11,12 * * ?

 or

0 0/40 11,12 * * ?

Hope this helps you,

Matt

[#8]

Hi @MattWho 

I want corn driven expression for 11:40 am separate and I want corn driven expression for 12:00pm separate

Please send those expressions

[#9]

@hargav 

NiFi processor scheduled every day at 11:40AM:

0 40 11 * * ? *

NiFi processor Scheduled every day at 12:00PM:

0 0 12 * * ? *

If you found that the provided solution(s) assisted you with your query, please take a moment to login and click Accept as Solution below each response that helped.

Thank you,

Matt

[#10]

Hi @MattWho  

I was used below corn expression for merge record but the data  was not went to the queue in nifi platform ,We need to change any configuration in merge record ?

please suggest me any solution 

0 40 11 * * ? *