AutoSys Architecture and Components
- AutoSys has four core components: Event Server (database), Event Processor (scheduler daemon), Remote Agents (job executors), and client tools.
- The Event Server is the single source of truth — every job definition, event, and status lives there.
- The Event Processor continuously evaluates job conditions and triggers agents — it never executes jobs directly.
Before you write a single line of JIL or schedule your first job, it helps to understand how AutoSys actually works under the hood. The architecture is straightforward but knowing what each component does — and why — will save you a lot of head-scratching when things go wrong in production.
AutoSys has four major components that work together: the Event Server, the Event Processor, Remote Agents, and client tools. Each has a clear job, and understanding the flow between them makes debugging much easier.
The Event Server — the source of truth
The Event Server is a relational database (typically Sybase or Oracle) that stores everything AutoSys needs to operate. This includes all job definitions (what to run, when, where, under which conditions), all events that have occurred (job started, job succeeded, job failed), global variable values, machine definitions, calendar definitions, and monitor and report definitions.
When a job finishes and reports its status, that status goes into the Event Server. When the Event Processor needs to know whether a dependent job's condition is met, it queries the Event Server. It's the single source of truth for the entire AutoSys environment.
The Event Processor — the brain
The Event Processor (also called the scheduler or the event daemon) is the most important component. It runs continuously, polling the Event Server for events. When it detects that a job's starting conditions are met — the right time has arrived, dependent jobs have succeeded, the machine is available — it triggers the job to run on the appropriate agent.
The Event Processor also handles time-based scheduling, evaluates job condition logic, and manages the overall state machine for each job. On Unix/Linux it's started with the eventor command. There is only ever one Event Processor running per AutoSys instance.
# Start the AutoSys event processor (UNIX only) eventor # Check if AutoSys components are up autoping # Check AutoSys flags and system status autoflags -a
Event Processor: RUNNING
Instance: ACE
Remote Agents — where the work actually happens
Remote Agents run on every machine where AutoSys needs to execute jobs. When the Event Processor decides a job should run, it sends a message to the Remote Agent on the target machine. The agent starts the process, monitors it, captures the exit code, and reports the result back to the Event Server.
Agents can be extended with plugins for specific integrations — SAP, Oracle E-Business, PeopleSoft, and others. If an agent goes down, jobs that are supposed to run on that machine go into PEND_MACH status and wait until the agent comes back up.
Client tools — how you interact with AutoSys
Client tools are the interfaces you use to define, manage, and monitor jobs. The main ones are: jil — the command-line JIL processor for creating and modifying job definitions; autorep — reports job status and definitions; sendevent — manually triggers events like starting a job or putting it on hold; autostatus — checks the current status of a specific job; and the WCC Web UI — a browser-based dashboard for monitoring job flows visually.
Most experienced AutoSys administrators work primarily from the command line using jil, autorep, and sendevent. The GUI is useful for monitoring and for people less comfortable with CLI.
# Check status of a specific job autostatus -J daily_report # Get a detailed report on a job autorep -J daily_report -d # List all jobs in a box autorep -J box_name% # Check machine status autorep -M prod-server-01
Status: SUCCESS
Last Run: 03/19/2026 06:02:15
Exit Code: 0
| Component | Type | Runs on | Key responsibility |
|---|---|---|---|
| Event Server | Database (Sybase/Oracle) | Dedicated server | Stores all job defs, events, state |
| Event Processor | Daemon/service | AutoSys server | Evaluates conditions, triggers jobs |
| Remote Agent | Service | Every target machine | Executes jobs, reports results |
| jil | CLI client | Any client machine | Define/modify job definitions |
| autorep | CLI client | Any client machine | Report job status and definitions |
| sendevent | CLI client | Any client machine | Manually trigger events |
| WCC (Web UI) | Browser GUI | Browser | Visual monitoring and management |
🎯 Key Takeaways
- AutoSys has four core components: Event Server (database), Event Processor (scheduler daemon), Remote Agents (job executors), and client tools.
- The Event Server is the single source of truth — every job definition, event, and status lives there.
- The Event Processor continuously evaluates job conditions and triggers agents — it never executes jobs directly.
- Remote Agents run on target machines and execute the actual work, reporting results back to the Event Server.
- PEND_MACH is one of the most common production issues and is caused by agent machines going offline or running out of disk space.
⚠ Common Mistakes to Avoid
- ✕Assuming the Event Processor runs the job itself — it doesn't. It only triggers the Remote Agent, which actually executes the job on the target machine.
- ✕Running multiple Event Processor instances on the same AutoSys instance — this causes unpredictable behaviour. There must be exactly one.
- ✕Not monitoring the Event Server database size — over time, event history accumulates and can cause performance issues if not purged regularly.
- ✕Forgetting that the agent user account needs the right permissions on the target machine to execute the job's command.
Interview Questions on This Topic
- QWhat are the four main components of AutoSys architecture?
- QWhat does the Event Processor do and how does it interact with the Event Server?
- QWhat happens to jobs when a Remote Agent machine goes down?
- QWhat is PEND_MACH status and what causes it?
- QCan you run multiple Event Processors for the same AutoSys instance?
Frequently Asked Questions
What database does AutoSys use for the Event Server?
AutoSys traditionally used Sybase as its backend database. Newer versions also support Oracle. The Event Server stores all job definitions, events, and system state.
What happens if the Event Processor crashes?
If the Event Processor goes down, no new jobs will be triggered. Jobs that are already running will continue until they complete. AutoSys supports a shadow scheduler that can take over if the primary Event Processor fails, providing high availability.
Can I run AutoSys jobs on Windows machines?
Yes. AutoSys Remote Agents are available for both Unix/Linux and Windows. You can schedule jobs to run on Windows machines the same way as Unix machines, though some command-line tools like eventor are Unix-only.
What is the difference between the Event Server and the Event Processor?
The Event Server is the database that stores all data. The Event Processor is the daemon that reads from the Event Server, evaluates job conditions, and triggers jobs. One is data storage; the other is the decision engine.
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