This function is called when we receive a master configuration via a * PING, PONG or UPDATE packet. What we receive is a node, a configEpoch of the * node, and the set of slots claimed under this configEpoch. * * What we do is to rebind the slots with newer configuration compared to our * local configuration, and if needed, we turn ourself into a replica of the * node (see the function comme
| 1633 | * Sometimes it is not actually the "Sender" of the information, like in the |
| 1634 | * case we receive the info via an UPDATE packet. */ |
| 1635 | void clusterUpdateSlotsConfigWith(clusterNode *sender, uint64_t senderConfigEpoch, unsigned char *slots) { |
| 1636 | int j; |
| 1637 | clusterNode *curmaster = NULL, *newmaster = NULL; |
| 1638 | /* The dirty slots list is a list of slots for which we lose the ownership |
| 1639 | * while having still keys inside. This usually happens after a failover |
| 1640 | * or after a manual cluster reconfiguration operated by the admin. |
| 1641 | * |
| 1642 | * If the update message is not able to demote a master to slave (in this |
| 1643 | * case we'll resync with the master updating the whole key space), we |
| 1644 | * need to delete all the keys in the slots we lost ownership. */ |
| 1645 | uint16_t dirty_slots[CLUSTER_SLOTS]; |
| 1646 | int dirty_slots_count = 0; |
| 1647 | |
| 1648 | /* We should detect if sender is new master of our shard. |
| 1649 | * We will know it if all our slots were migrated to sender, and sender |
| 1650 | * has no slots except ours */ |
| 1651 | int sender_slots = 0; |
| 1652 | int migrated_our_slots = 0; |
| 1653 | |
| 1654 | /* Here we set curmaster to this node or the node this node |
| 1655 | * replicates to if it's a slave. In the for loop we are |
| 1656 | * interested to check if slots are taken away from curmaster. */ |
| 1657 | curmaster = nodeIsMaster(myself) ? myself : myself->slaveof; |
| 1658 | |
| 1659 | if (sender == myself) { |
| 1660 | serverLog(LL_WARNING,"Discarding UPDATE message about myself."); |
| 1661 | return; |
| 1662 | } |
| 1663 | |
| 1664 | for (j = 0; j < CLUSTER_SLOTS; j++) { |
| 1665 | if (bitmapTestBit(slots,j)) { |
| 1666 | sender_slots++; |
| 1667 | |
| 1668 | /* The slot is already bound to the sender of this message. */ |
| 1669 | if (server.cluster->slots[j] == sender) continue; |
| 1670 | |
| 1671 | /* The slot is in importing state, it should be modified only |
| 1672 | * manually via redis-trib (example: a resharding is in progress |
| 1673 | * and the migrating side slot was already closed and is advertising |
| 1674 | * a new config. We still want the slot to be closed manually). */ |
| 1675 | if (server.cluster->importing_slots_from[j]) continue; |
| 1676 | |
| 1677 | /* We rebind the slot to the new node claiming it if: |
| 1678 | * 1) The slot was unassigned or the new node claims it with a |
| 1679 | * greater configEpoch. |
| 1680 | * 2) We are not currently importing the slot. */ |
| 1681 | if (server.cluster->slots[j] == NULL || |
| 1682 | server.cluster->slots[j]->configEpoch < senderConfigEpoch) |
| 1683 | { |
| 1684 | /* Was this slot mine, and still contains keys? Mark it as |
| 1685 | * a dirty slot. */ |
| 1686 | if (server.cluster->slots[j] == myself && |
| 1687 | countKeysInSlot(j) && |
| 1688 | sender != myself) |
| 1689 | { |
| 1690 | dirty_slots[dirty_slots_count] = j; |
| 1691 | dirty_slots_count++; |
| 1692 | } |
no test coverage detected