Spring #Scheduled fixedDelay is not working as expected - spring

Question

I have 2 jobs running asynchronously one which triggers everymin and another with a fixed delay.
#Scheduled(fixedDelay=30000)
public void runJob() {
try {
JobParameters jobParameters = new JobParametersBuilder().addLong("time",System.currentTimeMillis()).toJobParameters();
JobExecution execution=jobLauncher.run(job,jobParameters);
LOGGER.info(execution.getExitStatus());}
catch (Exception e) {
try {
throw new SystemException("Scheduler ERROR :: Error coocured during Job run "+e);
} catch (SystemException e1) {
LOGGER.error("Scheduler ERROR :: Error coocured during Job run "+e);
}
}
}
#Scheduled(cron = "0 0/1 * * * ?")
public void runJob2() {
try {
JobParameters jobParameters = new JobParametersBuilder().addLong("time",System.currentTimeMillis()).toJobParameters();
JobExecution execution=jobLauncher.run(job2,jobParameters);
LOGGER.info(execution.getExitStatus());}
catch (Exception e) {
try {
throw new SystemException("ERROR:: Exception occured"+e);
} catch (SystemException e1) {
LOGGER.error("ERROR:: JOB Launching exception happened"+e);
}
}
}
as fixedDelay says "the duration between the end of last execution and the start of next execution is fixed" but for me its triggering with a fixed delay between the starts of last and next execution.
2018-05-11 **12:48:00.016** INFO 2112 --- [ taskExecutor-5] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=systemStartJob]] launched with the following parameters: [{time=1526023080016}]
2018-05-11 12:48:00.016 INFO 2112 --- [ taskExecutor-5] org.sapient.t1automation.SystemListener : Intercepting system Job Execution - Before Job!
2018-05-11 12:48:00.017 INFO 2112 --- [ taskExecutor-5] o.s.batch.core.job.SimpleStepHandler : Executing step: [systemStartStep]
.
.
.
.
2018-05-11 **12:48:24.721** INFO 2112 --- [ taskExecutor-6] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=sendMailJob]] launched with the following parameters: [{time=1526023104706}]
2018-05-11 12:48:24.737 INFO 2112 --- [ taskExecutor-6] org.sapient.t1automation.MailListener : Intercepting Job Excution - Before Job!
2018-05-11 12:48:24.737 INFO 2112 --- [ taskExecutor-6] o.s.batch.core.job.SimpleStepHandler : Executing step: [sendMailStep1]
.
.
.
2018-05-11 12:48:44.533 INFO 2112 --- [ taskExecutor-6] org.sapient.t1automation.MailListener : Intercepting Job Excution - After Job!
2018-05-11 12:48:44.533 INFO 2112 --- [ taskExecutor-6] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=sendMailJob]] completed with the following parameters: [{time=1526023104706}] and the following status: [COMPLETED]
2018-05-11 12:48:45.001 INFO 2112 --- [ taskExecutor-3] o.s.t.service.mail.MailReader : Mail:: Mails to process. 1
2018-05-11 12:48:45.017 INFO 2112 --- [ taskExecutor-3] org.sapient.t1automation.MailListener : Intercepting Job Excution - After Job!
2018-05-11 12:48:45.017 INFO 2112 --- [ taskExecutor-3] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=sendMailJob]] completed with the following parameters: [{time=1526023044672}] and the following status: [COMPLETED]
here the time between start of 2 executions is 30s instead of between end of last and start of next execution.

Answer 1

Check the execution time of you code. It may be possible your code executes within a second, hence you cant see the time difference.
Sample example:
#Scheduled(fixedDelay = 3000)
private void test() {
System.out.println("test -> " + new Date());
try {
Thread.sleep(2000);
}
catch (Exception e) {
System.out.println("error");
}
}
Output
test -> Fri May 11 13:45:35 IST 2018
test -> Fri May 11 13:45:40 IST 2018
test -> Fri May 11 13:45:45 IST 2018
test -> Fri May 11 13:45:51 IST 2018
test -> Fri May 11 13:45:56 IST 2018
Here you can see, difference between every print is 5 seconds instead of 3 seconds.
For debugging, you can add logs at start and end of the code. Also, Thread.sleep() for delay.