The agent couldn't open the std_out_file or std_err_file, so the command never ran.
The job fails in about 0 seconds and its log is empty.
Four usual causes: the folder doesn't exist on the agent machine, the job owner can't write there, the disk is full, or another process has the file locked (common on Windows).
Fix a lock by writing a new file per run: std_out_file: /logs/$AUTO_JOB_NAME.$AUTORUN.out.
Check paths on the agent machine, as the job's owner.
✦ Definition~90s read
What is AutoSys Error Redirecting stdout?
Before running your command, the AutoSys agent opens the files named in std_out_file and std_err_file and connects the process to them. 'Error redirecting stdout' (or stderr) means that open failed, so the job failed before your command started.
★
The agent sets up a notebook before the job starts talking.
Plain-English First
The agent sets up a notebook before the job starts talking. If the shelf for the notebook doesn't exist, is locked, or is full, the agent gives up before the job says a word.
The job fails instantly, the log is empty, and the only message says AutoSys couldn't redirect stdout. There's nothing to debug in the script because it never ran. This guide explains when the agent opens the log files, the four reasons the open fails, and how to make it stop happening.
When the Agent Opens the Log Files
std_out_file and std_err_file aren't written by your script. The agent opens them before it starts your command and connects the process's output to them. If either open fails, the agent can't start the command, so the job fails with zero run time and nothing in the log.
Redirect errors happen before your command starts.
Cause 1: The Folder Doesn't Exist
The path is resolved on the agent machine. A folder that exists on your workstation, or on another batch server, doesn't help. The agent creates the file, not the folders above it.
check_dir.shBASH
1
2
# On the agent machine
ls -ld /apps/fin/logs || mkdir -p /apps/fin/logs
🎯 Key Takeaway
Create the folder on the agent machine.
Cause 2: The Owner Can't Write
The agent opens the file as the job's owner. If that user can't create or overwrite the file, the open fails. This often appears after a job's owner changes, or when an old log file was created by a different user.
If the log folder's filesystem is full, the open or the first write fails. Usually several jobs on the same machine fail at once.
check_space.shBASH
1
df -h /apps/fin/logs
🎯 Key Takeaway
Many jobs failing at once on one machine = check disk space.
Cause 4: The File Is Locked
On Windows, a file held open by another process can't be opened for writing. Log shippers, antivirus scanners and a previous run that hasn't fully released the file are the usual holders. The fix is to stop sharing one file across runs: AutoSys sets AUTO_JOB_NAME and AUTORUN for each run, so put them in the path.
Per-run files pile up. Add a scheduled job that deletes logs older than your retention period.
🎯 Key Takeaway
One file per run avoids every lock.
● Production incidentPOST-MORTEMseverity: high
Locked Out of Its Own Log
Symptom
GL_POST on winbatch02 failed at 06:00 with zero run time and 'Error redirecting stdout file: D:\logs\GL_POST.out'.
Assumption
The team investigated the script, which hadn't changed and never even started.
Root cause
Every run wrote to the same static file. A log shipper kept GL_POST.out open while uploading it, and Windows refused the next run's open.
Fix
Changed std_out_file and std_err_file to D:\logs\$AUTO_JOB_NAME.$AUTORUN.out and .err so every run gets a new file, and added a scheduled cleanup of old logs.
Key lesson
A 0-second failure with an empty log points at the log files.
Static log names collide with anything holding the file.
Paths are checked on the agent, as the job's owner.
Production debug guideFind why the log file can't be opened5 entries
Symptom · 01
Folder recently changed
→
Fix
Check it exists on the agent machine (not your workstation): ls -ld or dir.
Symptom · 02
Job owner changed
→
Fix
Test a write as the owner: sudo -u OWNER touch FOLDER/test.
Symptom · 03
Other jobs on the machine fail too
→
Fix
Check free space: df -h on the log folder.
Symptom · 04
Intermittent, same file every run
→
Fix
Something holds the file open (log shipper, antivirus, a previous run). Use per-run file names.
Symptom · 05
Path contains a variable
→
Fix
Confirm the variable is set where the agent resolves it, or use a literal path.
⚙ Quick Reference
5 commands from this guide
File
Command / Code
Purpose
job.jil
insert_job: GL_POST job_type: CMD
When the Agent Opens the Log Files
check_dir.sh
ls -ld /apps/fin/logs || mkdir -p /apps/fin/logs
Cause 1
check_write.sh
autorep -J FIN_LOAD -q | grep owner
Cause 2
check_space.sh
df -h /apps/fin/logs
Cause 3
fixed.jil
update_job: GL_POST
Cause 4
Key takeaways
1
The agent opens log files before the command starts.
2
A redirect error means the command never ran.
3
Four causes
missing folder, permissions, full disk, a lock.
4
Check on the agent machine, as the job's owner.
5
Use per-run log names to avoid locks.
Common mistakes to avoid
3 patterns
×
Debugging the script
Symptom
Nothing to find: it never ran.
Fix
Check the log path, permissions, space and locks on the agent.
×
Testing the path on your workstation
Symptom
It exists for you, not for the agent.
Fix
Check on the agent machine.
×
One static log file for every run
Symptom
Intermittent failures when something holds the file.
Fix
Use $AUTO_JOB_NAME.$AUTORUN in the file name.
INTERVIEW PREP · PRACTICE MODE
Interview Questions on This Topic
Q01SENIOR
A job fails with zero run time and 'Error redirecting stdout'. What happ...
Q01 of 01SENIOR
A job fails with zero run time and 'Error redirecting stdout'. What happened?
ANSWER
The agent couldn't open the std_out_file, so it never started the command. Check the folder exists on the agent, the owner can write, there's space, and nothing is locking the file.
01
A job fails with zero run time and 'Error redirecting stdout'. What happened?
SENIOR
FAQ · 3 QUESTIONS
Frequently Asked Questions
01
What does 'Error redirecting stdout file' mean in AutoSys?
The agent couldn't open the file in std_out_file, so it didn't start the job's command.
Was this helpful?
02
How do I give each AutoSys run its own log file?
Use $AUTO_JOB_NAME and $AUTORUN in std_out_file and std_err_file.
Was this helpful?
03
Why does it only fail sometimes?
Usually another process (log shipper, antivirus) has the file open at that moment.