Configuring High Availability (HA) with Different Installation Drives
search cancel

Configuring High Availability (HA) with Different Installation Drives

book

Article ID: 410129

calendar_today

Updated On:

Products

Autosys Workload Automation

Issue/Introduction

This guide explains whether an AutoSys High Availability (HA) environment can function correctly when the primary and backup (shadow) schedulers are installed on different drives. For example, you may have a primary scheduler on the E: drive and a backup scheduler on the D: drive. While this configuration is possible, you must verify that job definitions and scripts are configured correctly to avoid failures during a failover.

Environment

  • Product: AutoSys Workload Automation
  • Configuration: High Availability (Dual-Event Server / Shadowing Model)
  • Operating System: Windows (or any OS where installation paths might differ)

Resolution

An AutoSys High Availability (HA) configuration can work when the primary and backup schedulers are installed on different drives (e.g., E: and D:). The core HA mechanism is designed to be independent of the physical installation path. However, the success of a failover depends on avoiding hardcoded file paths in your job definitions and scripts.

 

The standard AutoSys HA model relies on database connectivity and network communication, not the local file system installation path. The key principles are:

  • Shared Database: Both the primary and shadow schedulers connect to the same AutoSys event database, which acts as the single source of truth for all job definitions, statuses, and heartbeats.
  • Network Communication: The schedulers monitor each other's status through the network and by writing heartbeat information to the shared database.
  • Failover Mechanism: If the shadow scheduler detects that the primary scheduler is no longer active, it automatically takes over workload processing.
  • Configuration Files: The HA behavior is controlled by the config.$AUTOSERV file (located in the $AUTOUSER directory on each server), which defines the database connection details and the role of each scheduler.

 

Critical Verification Steps for Different Drive Paths

While the HA logic itself is not affected by different installation drives, this setup can expose a common point of failure: hardcoded file paths. You must perform a thorough audit of your environment to prevent job failures after a failover.

  1. Audit Job Definitions for Hardcoded Paths
    This is the most critical area to investigate. If a job's command or profile attribute contains a hardcoded path with a drive letter, the job will fail if it runs on the server where that path does not exist.

    • Incorrect Example (will fail on the D: drive server):
      command: E:\apps\scripts\my_script.bat

    • Correct Example (uses an environment variable):
      command: %AUTOSYS%\bin\sendevent ...

    You must replace all hardcoded paths with environment variables. The %AUTOSYS% (Windows) or $AUTOSYS (UNIX/Linux) variable always resolves to the correct local installation directory on whichever server is active.

  2. Review Scripts, Profiles, and Integrations
    Any external scripts, user profiles, or third-party application integrations called by AutoSys jobs must also be free of hardcoded paths. Check the following:

    • Batch files (.bat), PowerShell scripts (.ps1), and shell scripts (.sh).
    • User profile scripts that set environment variables or paths.
    • Configuration files for any applications that integrate with AutoSys.

  3. Use UNC Paths for Shared Resources
    If jobs need to access files on a network share, always use a Universal Naming Convention (UNC) path instead of a mapped drive letter. A UNC path is accessible from any server on the network, regardless of local drive mappings.

    • Incorrect Example (relies on a local mapping):
      command: copy Z:\data\input.txt C:\temp\

    • Correct Example (uses a UNC path):
      command: copy \\fileserver01\share\data\input.txt C:\temp\

 

 

 

Additional Information

To ensure a successful HA configuration with different installation drives, follow these steps:

  1. Proceed with your current configuration (e.g., primary on E: drive, backup on D: drive).
  2. Initiate a comprehensive audit of all job definitions and associated scripts to find and remove any hardcoded, drive-specific paths.
  3. Replace all hardcoded paths with environment variables (like %AUTOSYS%) for local files or UNC paths for shared network resources.
  4. Thoroughly test the failover process in a non-production environment. Trigger a manual failover and validate that jobs run successfully on both the primary and backup nodes.
Powered by Wolken Software