Synnefo » snf-ganeti

nodeEvacInstance nl il ChangeAll

                 inst@(Instance.Instance {Instance.diskTemplate = DTDrbd8})

                 avail_nodes =

  do

    let primary = Container.find (Instance.pNode inst) nl

        idx = Instance.idx inst

        gdx = instancePriGroup nl inst

        no_nodes = Left "no nodes available"

    -- if the primary is offline, then we first failover

    (nl1, inst1, ops1) <-

        if Node.offline primary

        then do

          (nl', inst', _, _) <-

              annotateResult "Failing over to the secondary" $

              opToResult $ applyMove nl inst Failover

          return (nl', inst', [Failover])

        else return (nl, inst, [])

    -- we now need to execute a replace secondary to the future

    -- primary node

    (nl2, inst2, _, new_pdx) <- annotateResult "Searching for a new primary" $

                                eitherToResult $

                                foldl' (evacDrbdSecondaryInner nl1 inst1 gdx)

                                no_nodes avail_nodes

    let ops2 = ReplaceSecondary new_pdx:ops1

    -- since we chose the new primary, we remove it from the list of

    -- available nodes

    let avail_nodes_sec = new_pdx `delete` avail_nodes

    -- we now execute another failover, the primary stays fixed now

    (nl3, inst3, _, _) <- annotateResult "Failing over to new primary" $

                          opToResult $ applyMove nl2 inst2 Failover

    let ops3 = Failover:ops2

    -- and finally another replace secondary, to the final secondary

    (nl4, inst4, _, new_sdx) <-

        annotateResult "Searching for a new secondary" $

        eitherToResult $

        foldl' (evacDrbdSecondaryInner nl3 inst3 gdx) no_nodes avail_nodes_sec

    let ops4 = ReplaceSecondary new_sdx:ops3

        il' = Container.add idx inst4 il

        ops = concatMap (iMoveToJob nl4 il' idx) $ reverse ops4

    return (nl4, il', ops)