Jenkins BUILD_NUMBER limit - maximum build number

Question

Curious to know what's the maximum number a Jenkins build number (BUILD_NUMBER) can get? I tried to find online but couldn't find this info.

Is it infinite or has some limit (being INT or INT64 or some other type)?

PS: I'm NOT looking for how to reset it back to #1 or #N using the following plugin or set it value to a given name (using Set build name plugin). https://wiki.jenkins-ci.org/display/JENKINS/Next+Build+Number+Plugin

To find it's limit, using Next Build Number plugin - when I set the build to "65,535", it still worked in getting me 65536 successfully and I kept increasing this value to 999999999 (9 times), and it still worked i.e. the next build ran which was 1000000000 and reaped a valid Jenkins build# for few other runs/builds.

When I tried to set the next build number as: 9999999999 (10 times), Jenkins plugin barfed with an error mesg (which shows the next build number I set was not an INTEGER i.e. not in the range):

A problem occurred while processing the request. Please check our bug tracker to see if a similar problem has already been reported. If it is already reported, please vote and put a comment on it to let us gauge the impact of the problem. If you think this is a new issue, please file a new issue. When you file an issue, make sure to add the entire stack trace, along with the version of Jenkins and relevant plugins. The users list might be also useful in understanding what has happened.

Stack trace

javax.servlet.ServletException: Build number must be an integer
    at org.jvnet.hudson.plugins.nextbuildnumber.NextBuildNumberAction.doSubmit(NextBuildNumberAction.java:87)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

Pretty decent bet it's a 32-bit integer then, surely? Largest value 4,294,967,296 — jonrsharpe
@jonrsharpe it didn't take that value and barfed. To my miss, It the unsigned value for int i.e. it'll take 2147483647 as the last value. — AKS
Then you've still answered your own question. What are you asking? — jonrsharpe
I think I shouldn't have :) or I didn't remember INT limits. Strange thing I found though. If I give a NEGATIVE number while setting the build number, the plugin doesn't error out that means, BUILD_NUMBER is NOT UNSIGNED but then it's not generating build# in -22 -21 -20 ... either. — AKS
Why did you think it would, given that you literally just worked out that it was a signed 32-bit integer? — jonrsharpe

AKS AKS · Accepted Answer · 2016-11-28T21:08:16

Found Jenkins BUILD_NUMBER is a SIGNED Integer data type and INT signed limits are:

int 2 or 4 bytes    -32,768 to 32,767 or -2,147,483,648 to 2,147,483,647

Thus, the last value that a Jenkins job can be set or built is: 2147483647 (4 bytes here). Setting anything above this number will generate the expected INT limit error.

Noticed the following issue as well, with SET NEXT BUILD NUMBER plugin:

If I set the next build number between -2147483648 or 2147483647 (positive), this plugin it works in both cases i.e. giving Negative or a positive Number and setting it doesn't error out. BUT, if you have already reached at build# 2147483647 (under Job history), then even setting the build# to 1 did NOT generate the next build as 1 or 2 . or 3 and so on.
As the BUILD_NUMBER is SIGNED (-N to +N in the above range) and for ex: setting -22 works for setting the next build# using the plugin, it didn't give me build# -21 or build# 21 in my case.

What's happening is, while providing a negative/lower value than the last/previous build# then this plugin is taking that value within the limit BUT not actually doing anything / giving me the expected BUILD#. When I'm clicking on Build Now / every time you hit Build Now and if you click on "Set Next Build Number" to check the value, I noticed that the number listed in the box was auto-decrementing by the number of times I hit "Build Now" (this happens only when you have reached the limit) and negative/lower value has no effect for the next build number (as per the plugin docs).

I tested this by creating a new test_job (discarded old builds by retaining only 1 build):

clicked on Build Now, got Build# 1.
Set next build number to 100.
Clicked Build Now, got Build# 100, Clicked Build now, Got build# 101.
Set Build number to 11 this time.
Clicked Build Now, but instead of giving me build# 12, Jenkins gave me build# 102 (PS: that's the intended behavior by this plugin as per it's documentation as setting next build number to a lower number N will not do anything).

Jenkins BUILD_NUMBER limit - maximum build number

1 Answers