Failed to sync Periodic migration log error

[Yogesh Mude]

I was working on the migration the JIra DC to cloud and getting the below error due to which the migration getting failed.

I have removed the JIRA_HOME/plugin/.bundled and .osgi but still the same error.

2025-10-03 05:57:18,765+0000 Caesium-1-1 ERROR ServiceRunner [c.a.j.migration.log.PeriodicMigrationLogService] Failed to sync periodic migration log for log period (2025-10-03T05:57:17Z - 2025-10-03T06:57:17Z)
com.atlassian.jira.migration.log.PeriodicMigrationLogException: Failed to upload periodic migration log file (/var/atlassian/application-data/jira/log/atlassian-jira-periodic-migration-20251003055717.0.log) for migration (27381639-c527-4833-9c90-fd68dc22e75c)
at com.atlassian.jira.migration.log.PeriodicMigrationLogService.uploadLogFileToMCS(PeriodicMigrationLogService.kt:418)
at com.atlassian.jira.migration.log.PeriodicMigrationLogService.syncLogPeriod(PeriodicMigrationLogService.kt:248)
at com.atlassian.jira.migration.log.PeriodicMigrationLogService.syncMigrationLogs(PeriodicMigrationLogService.kt:212)
at com.atlassian.jira.migration.log.PeriodicMigrationLogService.sync(PeriodicMigrationLogService.kt:86)
at com.atlassian.jira.migration.log.PeriodicMigrationLogService.sync$default(PeriodicMigrationLogService.kt:76)
at com.atlassian.jira.migration.log.PeriodicMigrationLogJobRunnerImpl.runJob(PeriodicMigrationLogJobRunnerImpl.kt:104)
at com.atlassian.scheduler.core.JobLauncher.runJob(JobLauncher.java:134)
at com.atlassian.scheduler.core.JobLauncher.launchAndBuildResponse(JobLauncher.java:106)
at com.atlassian.scheduler.core.JobLauncher.launch(JobLauncher.java:90)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService.launchJob(CaesiumSchedulerService.java:500)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService.executeLocalJobWithRetryOnFailure(CaesiumSchedulerService.java:463)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService.executeQueuedJob(CaesiumSchedulerService.java:413)
at com.atlassian.scheduler.caesium.impl.SchedulerQueueWorker.executeJob(SchedulerQueueWorker.java:66)
at com.atlassian.scheduler.caesium.impl.SchedulerQueueWorker.executeNextJob(SchedulerQueueWorker.java:60)
at com.atlassian.scheduler.caesium.impl.SchedulerQueueWorker.run(SchedulerQueueWorker.java:35)
at java.base/java.lang.Thread.run(Unknown Source)
Caused by: com.atlassian.jira.migration.log.PeriodicMigrationLogException: Failed to retrieve cloud site for migration (27381639-c527-4833-9c90-fd68dc22e75c)
at com.atlassian.jira.migration.log.PeriodicMigrationLogService.getContainerToken(PeriodicMigrationLogService.kt:451)
at com.atlassian.jira.migration.log.PeriodicMigrationLogService.uploadLogFileToMCS(PeriodicMigrationLogService.kt:412)
... 15 more

[Yogesh Mude]

Strange part is it says... Failed to start transfer: 503 Service Unavailable from POST http://jira-migration-target.mesh:20021/api/migrations/executor/v1/transfer

and there is no error dertails in the log file.