How AutoSys File Watcher Works: A Complete Guide

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**AutoSys** is a powerful job scheduling tool used for automating the execution of various processes, scripts, and applications across multiple platforms. One of the advanced features it offers is **File Watcher Jobs**. These jobs allow users to trigger a task or process based on file system events, such as file creation, modification, or deletion. This feature is particularly useful in scenarios where the availability of a file is a prerequisite for starting the next step in a workflow.

In this article, we'll explore how the **AutoSys File Watcher** works, including how to set it up, its key configurations, and practical use cases.

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### What is an AutoSys File Watcher Job?

An **AutoSys File Watcher Job** is a special type of job designed to monitor the presence, modification, or absence of a file or directory in a filesystem. Once the specified condition (such as file creation or modification) is met, the job triggers the next dependent job in the workflow.

For example, if a file must be created or updated in a particular folder before a batch process can begin, an AutoSys File Watcher job can be configured to monitor that directory and launch the process as soon as the file appears.

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### Key Parameters of File Watcher Jobs

To create and configure a **File Watcher Job** in AutoSys, several parameters must be defined in the Job Information Language (JIL). Some of the critical parameters include:

1. **Job Type:**

   - The job type for file watcher jobs is `FW`.

   - Example: `job_type: FW`

2. **File Name (watch_file):**

   - The path and name of the file to be monitored. You can use wildcards like `*` or `?` to specify patterns.

   - Example: `watch_file: /path/to/directory/filename.txt`

3. **File Watcher Conditions (watch_file_criteria):**

   - Defines the condition under which the job will be triggered. The common options are:

     - `c`: To monitor file creation.

     - `m`: To monitor file modification.

     - `d`: To monitor file deletion.

   - Example: `watch_file_criteria: c`

4. **Interval (watch_interval):**

   - This parameter defines how frequently AutoSys should check the file or directory for the specified event. It is set in seconds.

   - Example: `watch_interval: 60` (checks every 60 seconds)

5. **Max Watch Time (watch_file_min_age):**

   - Specifies the minimum age (in seconds) a file must be before triggering the file watcher job.

   - Example: `watch_file_min_age: 120` (file must exist for at least 2 minutes before triggering)

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### How to Create a File Watcher Job in AutoSys

To create a file watcher job in AutoSys, a JIL (Job Information Language) script is used. Below is a sample JIL code that creates a file watcher job:

```bash

insert_job: file_watcher_job_name

job_type: FW

machine: server_name

watch_file: /path/to/directory/myfile.txt

watch_file_criteria: c

watch_interval: 60

watch_file_min_age: 120

description: "This job triggers when myfile.txt is created in the directory"

owner: user_name

std_out_file: /path/to/output_file.log

std_err_file: /path/to/error_file.log

alarm_if_fail: 1

```

### Key Fields in the JIL Script:

- **job_type**: Specifies this is a File Watcher job (`FW`).

- **machine**: Defines the server where the job will be monitored.

- **watch_file**: The path and file being monitored.

- **watch_file_criteria**: Condition for triggering the job (in this case, `c` for creation).

- **watch_interval**: The job will check the file every 60 seconds.

- **watch_file_min_age**: The job will trigger only if the file has existed for at least 120 seconds.

- **owner**: Defines who owns the job (the user running the job).

- **std_out_file** and **std_err_file**: Specify log files for standard output and errors.

- **alarm_if_fail**: If the job fails, an alarm is triggered.

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### Practical Use Cases of File Watcher Jobs

1. **File Arrival Monitoring:**

   One of the most common uses of a file watcher is to monitor when a file arrives in a directory. For example, when a new data file is uploaded to a directory, the file watcher can trigger an ETL (Extract, Transform, Load) process.

2. **File Modification Detection:**

   If a file in a directory is being regularly updated (e.g., a log file or a transaction file), you can configure a file watcher job to monitor modifications (`watch_file_criteria: m`). This can trigger subsequent jobs, such as archiving or further data processing.

3. **File Deletion Monitoring:**

   In scenarios where a file’s deletion is a signal to trigger the next steps, the file watcher can be set to watch for deletions (`watch_file_criteria: d`). For example, after a file is processed and deleted by a system, a cleanup or notification job could be triggered.

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### Best Practices for File Watcher Jobs

1. **Set Proper Watch Intervals:**

   Avoid setting overly frequent intervals, as it can unnecessarily strain system resources. Use an interval that balances between efficiency and resource use, depending on how critical the file monitoring is.

2. **Use Wildcards Wisely:**

   If monitoring a directory with many files, be cautious when using wildcards in the `watch_file` parameter to avoid unintentional file matches.

3. **Log Outputs and Errors:**

   Ensure that the `std_out_file` and `std_err_file` are configured to capture any output and errors, making it easier to debug any issues.

4. **Chain Jobs for File-Dependent Workflows:**

   Use file watcher jobs to trigger other jobs in a workflow when a file-related condition is met. You can chain multiple jobs using conditions based on file creation, modification, or deletion.

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### Conclusion

AutoSys File Watcher Jobs are an essential tool for automating tasks that depend on file system events. By configuring file watcher jobs to monitor file creation, modification, or deletion, organizations can streamline workflows and ensure that processes are triggered as soon as the required files become available. Properly configuring these jobs with intervals and conditions can significantly improve operational efficiency, especially in complex data-driven environments.

By following the steps and examples in this article, you should be able to create and manage file watcher jobs in AutoSys effectively.