Hercules: Job Queue and Settings
The Job Queue Screen gives an overview of all of the jobs in the Hercules system, with the ability to show more detailed information for each job.
To view the Job Queue, either click on the "Job Queue" button on the Button Bar across the bottom of the Hercules GUI or right click on any of the Queues at the top of the screen and select "Details". To get back to the main screen, click the green "Overview" button.
The Job Queue can be accessed by clicking the Job Queue button on the bottom of the Hercules GUI Overview page or from each Individual Job list at the top of the page. The job list allows viewing of jobs and sorting based on the job type, status, and date.
The status of a Hercules job is defined as:
| Running | The job is currently being processed by a tape drive |
| Waiting | The job is ready to be processed but there are no drives free to perform the job |
| Pending | The job requires a bar-coded tape which is not present |
Highlighting a job in the job list shows the extended job information panel, this shows additional information regarding the job, such as the barcode of the tape it will use (if the job is pending, this is the barcode which needs to be created).
Event Log Screen
The Event Log Screen is the primary location for the user to find reports about system errors and alerts. Items in the event log have a description and associated importance value; this value indicates the severity of the reported problem, from zero (meaning the problem has little or no impact on the system) to ten (a critical system error that requires user action).
Most of the time the reports are notifications of problems that are dealt with autonomously by the Hercules system, however it is possible that an event is severe enough to warrant user intervention.
Most Errors are automatically retried, but if the problem persists, the log is useful in ensuring that the files can be archived at a later date.
Hercules Job Prioritization
The Hercules Configuration Screen is the main configuration screen on the GUI. It provides users with a large number of options for defining how the Hercules schedules, prioritises and manages jobs. The configuration options are defined in two ways:
- Priority Rules
- General Settings
Priority rules define how priorities are assigned to jobs, various conditions may be met which will optionally modify the priority of jobs. This system is in place to increase the efficiency of the Hercules, customised to different situations.
General Settings define optional parameters of the Hercules’s operation; these do not affect the priorities of jobs.
Selecting a rule or setting from the Priority Screen presents the user with a panel from which they can configure the rule or settings options. The following is a brief description of the available priority rules and settings:
| Name | Job Age Rule |
| Description | If a job has been waiting for more than a specified amount of time, it will receive a bonus to its priority. The bonus it receives can be specified on this page, to disable this rule you can specify a custom priority bonus of zero.
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| Purpose | This rule helps to prevent jobs of a low priority being stuck behind other jobs for extended durations. |
| Name | Time of Day Rule |
| Description | At different times of the day, specified job types are given a bonus to their priorities. Times at which priorities are applied are shown on the graph, which displays an entire 24 hour period horizontally. A time period to apply a priority bonus is added with the green plus buttons, the pressing of which allows you to specify a start and end time by clicking on the corresponding times in the graph.
Bonus periods in the graph are modified by dragging the boxes on the graph, or clicking on the sides of the boxes to extend their start/end time. Bonus periods are deleted by clicking the deletion button next to the corresponding entry in the grid. They may also be disabled by clicking the green tick (turning it to a red cross). |
| Purpose | This rule allows you to have a priority system for jobs based on the time of day, this is often useful when users need to work with restored data during office hours. |
| Name | Media In Drive Rule |
| Description | If the media required for a job is already present in a tape drive, that job will receive a bonus to its priority. The priority bonus may be specified from this panel, to disable the rule specify a custom bonus of zero. |
| Purpose | This rule reduces the amount of removing and inserting the tape robot has to perform, thereby increasing the productivity of the system.
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General Settings
The General Settings are directly below the Priority Engine Settings. These rules control the size of the Hercules Jobs, when to eject a tape after a Job was finished, and other parameters associated with how the Hercules Controller and Creator manage the system.
| Name | Tape Ejection |
| Description
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Tapes are automatically ejected from drives when they have been idle for a set period of time. |
| Purpose | This setting prevents tapes from remaining in tape drives for extended periods of time, where they can become hot, reducing their life. |
| Name | Retry After Error |
| Description | When a file fails to archive, the system will attempt to archive it again up to a fixed number of times. Retrying may be disabled by clicking ‘Never retry files after errors’, otherwise a number of retries may be specified. Note: certain errors will cause the system to not retry archiving. |
| Purpose | This setting allows you to balance speed (less/no retries) with safety (more retries).
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| Name | Job Minimum Duration |
| Description | A job must reach a certain size before it is started by the system; this size is defined by the amount of time the job will take to complete.
However, if a job has been waiting for too long (and still does not match the minimum job size) it will be started anyway. The time it takes for this to happen may be set here as well. |
| Purpose | This setting increases the efficiency of the Hercules System by preventing the processing of many small jobs. Small jobs are undesirable because when more small jobs are processed an increasing large percentage of time is taken to move tapes to and from drives in relation to actual read/write operations on the drive. |
| Name | Job Maximum Duration |
| Description | The maximum amount of time that any job will run under normal conditions. |
| Purpose | This setting increases the efficiency of the Hercules System by preventing excessively long job from taking over the system operation. It is not safe for the system to be shutdown or stopped in the middle of a Job.
This setting also allows for balance in the Hercules operation so that other Jobs of higher priority can have an opportunity to run. |
| Name | New Media Threshold |
| Description | The total number of active media within a series. |
| Purpose | Allows for multiple active media to be used simultaneously in a Hercules system and can be beneficial for a system with multiple Tape Drives. |