github.com/anth0d/nomad@v0.0.0-20221214183521-ae3a0a2cad06/website/content/docs/job-specification/migrate.mdx (about)

     1  ---
     2  layout: docs
     3  page_title: migrate Stanza - Job Specification
     4  description: |-
     5    The "migrate" stanza specifies the group's migrate strategy. The migrate
     6    strategy is used to control the job's behavior when it is being migrated off
     7    of a draining node.
     8  ---
     9  
    10  # `migrate` Stanza
    11  
    12  <Placement
    13    groups={[
    14      ['job', 'migrate'],
    15      ['job', 'group', 'migrate'],
    16    ]}
    17  />
    18  
    19  The `migrate` stanza specifies the group's strategy for migrating allocations from
    20  [draining][drain] nodes. If omitted, a default migration strategy is applied.
    21  If specified at the job level, the configuration will apply to all groups
    22  within the job. Only service jobs with a count greater than 1 support migrate
    23  stanzas.
    24  
    25  ```hcl
    26  job "docs" {
    27    migrate {
    28      max_parallel     = 1
    29      health_check     = "checks"
    30      min_healthy_time = "10s"
    31      healthy_deadline = "5m"
    32    }
    33  }
    34  ```
    35  
    36  When one or more nodes are draining, only `max_parallel` allocations will be
    37  stopped at a time. Node draining will not continue until replacement
    38  allocations have been healthy for their `min_healthy_time` or
    39  `healthy_deadline` is reached.
    40  
    41  Note that a node's drain [deadline][deadline] will override the `migrate`
    42  stanza for allocations on that node. The `migrate` stanza is for job authors to
    43  define how their services should be migrated, while the node drain deadline is
    44  for system operators to put hard limits on how long a drain may take.
    45  
    46  See the [Workload Migration Guide](https://learn.hashicorp.com/tutorials/nomad/node-drain) for details
    47  on node draining.
    48  
    49  ## `migrate` Parameters
    50  
    51  - `max_parallel` `(int: 1)` - Specifies the number of allocations that can be
    52    migrated at the same time. This number must be less than the total
    53    [`count`][count] for the group as `count - max_parallel` will be left running
    54    during migrations.
    55  
    56  - `health_check` `(string: "checks")` - Specifies the mechanism in which
    57    allocations health is determined. The potential values are:
    58  
    59    - "checks" - Specifies that the allocation should be considered healthy when
    60      all of its tasks are running and their associated [checks][checks] are
    61      healthy, and unhealthy if any of the tasks fail or not all checks become
    62      healthy. This is a superset of "task_states" mode.
    63  
    64    - "task_states" - Specifies that the allocation should be considered healthy when
    65      all its tasks are running and unhealthy if tasks fail.
    66  
    67  - `min_healthy_time` `(string: "10s")` - Specifies the minimum time the
    68    allocation must be in the healthy state before it is marked as healthy and
    69    unblocks further allocations from being migrated. This is specified using a
    70    label suffix like "30s" or "15m".
    71  
    72  - `healthy_deadline` `(string: "5m")` - Specifies the deadline in which the
    73    allocation must be marked as healthy after which the allocation is
    74    automatically transitioned to unhealthy. This is specified using a label
    75    suffix like "2m" or "1h".
    76  
    77  [checks]: /docs/job-specification/service#check-parameters
    78  [count]: /docs/job-specification/group#count
    79  [drain]: /docs/commands/node/drain
    80  [deadline]: /docs/commands/node/drain#deadline