github.com/iqoqo/nomad@v0.11.3-0.20200911112621-d7021c74d101/website/pages/docs/job-specification/migrate.mdx (about)

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