2018-03-30 00:52:35 +00:00
|
|
|
---
|
2020-02-06 23:45:31 +00:00
|
|
|
layout: docs
|
|
|
|
page_title: migrate Stanza - Job Specification
|
|
|
|
sidebar_title: migrate
|
2018-03-30 00:52:35 +00:00
|
|
|
description: |-
|
|
|
|
The "migrate" stanza specifies the group's migrate strategy. The migrate
|
|
|
|
strategy is used to control the job's behavior when it is being migrated off
|
|
|
|
of a draining node.
|
|
|
|
---
|
|
|
|
|
|
|
|
# `migrate` Stanza
|
|
|
|
|
2020-02-06 23:45:31 +00:00
|
|
|
<Placement
|
|
|
|
groups={[
|
|
|
|
['job', 'migrate'],
|
|
|
|
['job', 'group', 'migrate']
|
|
|
|
]}
|
|
|
|
/>
|
2018-03-30 00:52:35 +00:00
|
|
|
|
|
|
|
The `migrate` stanza specifies the group's strategy for migrating off of
|
|
|
|
[draining][drain] nodes. If omitted, a default migration strategy is applied.
|
|
|
|
If specified at the job level, the configuration will apply to all groups
|
|
|
|
within the job. Only service jobs with a count greater than 1 support migrate
|
|
|
|
stanzas.
|
|
|
|
|
|
|
|
```hcl
|
|
|
|
job "docs" {
|
|
|
|
migrate {
|
|
|
|
max_parallel = 1
|
|
|
|
health_check = "checks"
|
|
|
|
min_healthy_time = "10s"
|
|
|
|
healthy_deadline = "5m"
|
|
|
|
}
|
|
|
|
}
|
|
|
|
```
|
|
|
|
|
|
|
|
When one or more nodes are draining, only `max_parallel` allocations will be
|
|
|
|
stopped at a time. Node draining will not continue until replacement
|
|
|
|
allocations have been healthy for their `min_healthy_time` or
|
|
|
|
`healthy_deadline` is reached.
|
|
|
|
|
|
|
|
Note that a node's drain [deadline][deadline] will override the `migrate`
|
|
|
|
stanza for allocations on that node. The `migrate` stanza is for job authors to
|
|
|
|
define how their services should be migrated, while the node drain deadline is
|
|
|
|
for system operators to put hard limits on how long a drain may take.
|
|
|
|
|
2020-03-27 15:39:03 +00:00
|
|
|
See the [Workload Migration Guide](https://learn.hashicorp.com/nomad/operating-nomad/node-draining) for details
|
2018-04-12 22:50:46 +00:00
|
|
|
on node draining.
|
|
|
|
|
2018-03-30 00:52:35 +00:00
|
|
|
## `migrate` Parameters
|
|
|
|
|
|
|
|
- `max_parallel` `(int: 1)` - Specifies the number of allocations that can be
|
|
|
|
migrated at the same time. This number must be less than the total
|
|
|
|
[`count`][count] for the group as `count - max_parallel` will be left running
|
|
|
|
during migrations.
|
|
|
|
|
|
|
|
- `health_check` `(string: "checks")` - Specifies the mechanism in which
|
|
|
|
allocations health is determined. The potential values are:
|
|
|
|
|
|
|
|
- "checks" - Specifies that the allocation should be considered healthy when
|
|
|
|
all of its tasks are running and their associated [checks][checks] are
|
|
|
|
healthy, and unhealthy if any of the tasks fail or not all checks become
|
2020-02-06 23:45:31 +00:00
|
|
|
healthy. This is a superset of "task_states" mode.
|
2018-03-30 00:52:35 +00:00
|
|
|
|
|
|
|
- "task_states" - Specifies that the allocation should be considered healthy when
|
|
|
|
all its tasks are running and unhealthy if tasks fail.
|
|
|
|
|
|
|
|
- `min_healthy_time` `(string: "10s")` - Specifies the minimum time the
|
|
|
|
allocation must be in the healthy state before it is marked as healthy and
|
|
|
|
unblocks further allocations from being migrated. This is specified using a
|
|
|
|
label suffix like "30s" or "15m".
|
|
|
|
|
|
|
|
- `healthy_deadline` `(string: "5m")` - Specifies the deadline in which the
|
|
|
|
allocation must be marked as healthy after which the allocation is
|
|
|
|
automatically transitioned to unhealthy. This is specified using a label
|
|
|
|
suffix like "2m" or "1h".
|
|
|
|
|
2020-02-06 23:45:31 +00:00
|
|
|
[checks]: /docs/job-specification/service#check-parameters
|
|
|
|
[count]: /docs/job-specification/group#count
|
|
|
|
[drain]: /docs/commands/node/drain
|
|
|
|
[deadline]: /docs/commands/node/drain#deadline
|