I am trying to understand when this trigger runs in Jenkins groovy script. Seems to me that Jenkins groovy script has some DSL for cron. Does anyone know when this cron job is triggered?
triggers {
cron('H 5 * * 7')
}
In H 5 * * 7 the H means hash. You can have digit in the first place, but H allows to distribute the load better.
H = minute when less load is expected, Jenkins will propose it the first time, after that it will stay more or less the same, if there are available agents to handle it.
5 = hour,
* = any value (every day),
* = any value (every month),
7 = 7th day of week (Sunday).
Reference:
Spread load evenly by using ‘H * * * *’ rather than ‘5 * * * *’
You can test it using the CRONTab tester.
This means to start at 5:00 on every sunday
https://crontab.guru/#0_5_*_*_7
Related
I want to schedule a jenkins job every 3 hours but exclude 6 o'clock. Something like the following statement which unfortunately is not possible in Jenkins:
H (0-5,7-23)/3 * * *
If I use the following statement it is treated separately:
H 0-5/3,7-23/3 * * *
Hence, the job starts at 0 o'clock even if the previous job was executed at 22 o'clock.
The worst solution would be to specify all times manually. Is there any better way?
You will need to explicitly set the hours.
So if you want to skip 6 PM then Jenkins corn will be
H 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,19,20,21,22,23 * * *
and if you want skip 6 AM then
H 0,1,2,3,4,5,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23 * * *
We have shared global scripts available for our Jenkins repos.
They work by importing the shared library and executing it.
Many people may use the same shared library.
Jenkinsfile (In my repo)
#Library('shared-stuff) _
runSharedTests()
runSharedTests (In a completely separate repo)
def call() {
def agent = getAgent()
def setVariable = setAVariable()
pipline {
agent {
label agent
}
stages {
stage('Do Something') {
steps {
executeSomething()
}
}
}
}
}
Is it possible to add a trigger to my Jenkinsfile that will trigger the runSharedTests pipeline periodically?
I cannot add the trigger directly to runSharedTests directly because then hundreds of repos will get that change and trigger.
In your case most suitable way to achieve your goal is making your jenkins job periodically. Your code does not need to be changed.
Configure → Build Triggers → Build periodically → Schedule:
To allow periodically scheduled tasks to produce even load on the system, the symbol H (for “hash”) should be used wherever possible. For example, using 0 0 * * * for a dozen daily jobs will cause a large spike at midnight. In contrast, using H H * * * would still execute each job once a day, but not all at the same time, better using limited resources.
The H symbol can be used with a range. For example, H H(0-7) * * * means some time between 12:00 AM (midnight) to 7:59 AM. You can also use step intervals with H, with or without ranges.
The H symbol can be thought of as a random value over a range, but it actually is a hash of the job name, not a random function, so that the value remains stable for any given project.
Beware that for the day of month field, short cycles such as */3 or H/3 will not work consistently near the end of most months, due to variable month lengths. For example, */3 will run on the 1st, 4th, …31st days of a long month, then again the next day of the next month. Hashes are always chosen in the 1-28 range, so H/3 will produce a gap between runs of between 3 and 6 days at the end of a month. (Longer cycles will also have inconsistent lengths but the effect may be relatively less noticeable.)
Empty lines and lines that start with # will be ignored as comments.
In addition, #yearly, #annually, #monthly, #weekly, #daily, #midnight, and #hourly are supported as convenient aliases. These use the hash system for automatic balancing. For example, #hourly is the same as H * * * * and could mean at any time during the hour. #midnight actually means some time between 12:00 AM and 2:59 AM.
Examples:
# every fifteen minutes (perhaps at :07, :22, :37, :52)
H/15 * * * *
# every ten minutes in the first half of every hour (three times, perhaps at :04, :14, :24)
H(0-29)/10 * * * *
# once every two hours every weekday (perhaps at 10:38 AM, 12:38 PM, 2:38 PM, 4:38 PM)
H 9-16/2 * * 1-5
# once a day on the 1st and 15th of every month except December
H H 1,15 1-11 *
Another way is using the triggers directive. It defines the automated ways in which the Pipeline should be re-triggered. For example:
pipeline {
agent any
triggers {
cron('H */4 * * 1-5')
}
stages {
stage('Example') {
steps {
echo 'Hello World'
}
}
}
}
But note that the declarative style is used here.
I want to set Jenkins to run a job every 3rd minute, but not starting at 0. Basically, I have 3 jobs and I want to cycle through them each minute.
The first job I can run every 3rd minute with */3 * * * *. But the second I tried 1/3 * * * * and it failed with hudson.remoting.ProxyException: line 1:2: unexpected token: /
How do I write this expression?
I think you're looking for:
job 1: 0-57/3 * * * *
job 2: 1-58/3 * * * *
job 3: 2-59/3 * * * *
Think of the cron minute entry as meaning "range/step" (or, "run this every step minutes over the minute range start-end)
Reference: I was able to figure it out from this excellent answer, which includes some helpful related links and a more in-depth explanation.
Schedule Jenkins Build Execution During Specific Times using Build periodically: (* * * * * *)?
For example: * * * * * * will execute builds continuously,
Is there a way to use the above approach but to run builds continuously between lets say 9am until 11pm.
Example:
Monday: time of execution: 9am until 11pm.
Tuesday: time of execution: 9am until 11pm.
To run jobs between 9am - 11pm every day, you could use the following:
* 9-23 * * *
To run jobs between 9am - 11pm only on Monday, you can use:
* 9-23 * * 1
And likewise for Tuesday:
* 9-23 * * 2
This website is a great resource for experimenting with cron job formats, and seeing a "human translation" for the syntax.
I think you can use the following cron expression : H 9-23 * * *
To build your own new cron expression keep the following link handy and test in Jenkins:
https://www.freeformatter.com/cron-expression-generator-quartz.html
A build that takes about three hours to complete needs to be scheduled for nightly building outside office hours: not sooner than 22:00 and not later than 3:59 next day.
I'd also like to use the "H symbol" to avoid collision with future nightly builds. From in-line help in Jenkins:
To allow periodically scheduled tasks to produce even load on the system, the symbol H (for “hash”) should be used wherever possible. For example, using 0 0 * * * for a dozen daily jobs will cause a large spike at midnight. In contrast, using H H * * * would still execute each job once a day, but not all at the same time, better using limited resources.
(How) can I schedule this using Jenkins? What I've tried was all considered invalid by Jenkins:
H H(22,23,0,1,2,3) * * *
Invalid input: "H H(22,23,0,1,2,3) * * *": line 1:7: expecting "-", found ','
H H22,23,0,1,2,3 * * *
Invalid input: "H H22,23,0,1,2,3 * * *": line 1:4: unexpected token: 22
H H(22-3) * * *
Invalid input: "H H(22-3) * * *": line 1:9: 1 is an invalid value. Must be within 1
and -18
Is it possible to achieve this without using plug-ins?
I think the closest you will get is to use:
H H(0-3) * * * This will run at some point between 0:00 and 3:59
#midnight This will run at some point between 0:00 and 2:59
The H(4-8) construct only works if the second items is larger then the first.
But you might as well fill in the hour yourself. Jenkins actually never changes the hour the jobs runs once it is set. It will basically create some random hour once you save the job and always run the job at that particular time.
Of course, you can also file a bug report or feature request that you should be able to specify this as H(22-3) or better, fix the code and submit a patch ;)
There is no direct support to write the expression like this, but since there is timezone support (now), you can work around this.
# DONT COPY PASTE - THIS DOESNT WORK!
# This is what we would like to write, but is not supported
H H(22-3) * * *
Above expression means we want to build somewhen between 22 PM and 3 AM, this is a 5 hour period, so we could write:
# Assuming we're in GMT+2 we can just shift the timezone
# so 22-03 becomes 10-15 wich is 12 hours earlier so the
# timezone is GMT-10
TZ=Etc/GMT-10
H H(10-15) * * *
I found this workaround in the comments of JENKINS-18313
UPDATE:
There is currently a bug JENKINS-57702 and the timezone GMT-XX is not evaluated correctly. A workaround is to use a equivalent timezone, in this example the one for Hawaii:
TZ=US/Hawaii
H H(10-15) * * *