|
@@ -279,24 +279,22 @@ shard will be allocated upon reopening the index.
|
|
|
[float]
|
|
[float]
|
|
|
=== Use two phase commit for Cluster State publishing (STATUS: DONE, v5.0.0)
|
|
=== Use two phase commit for Cluster State publishing (STATUS: DONE, v5.0.0)
|
|
|
|
|
|
|
|
-A master node in Elasticsearch continuously https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery-zen.html#fault-detection[monitors the cluster nodes]
|
|
|
|
|
|
|
+A master node in Elasticsearch continuously https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-fault-detection.html[monitors the cluster nodes]
|
|
|
and removes any node from the cluster that doesn't respond to its pings in a timely
|
|
and removes any node from the cluster that doesn't respond to its pings in a timely
|
|
|
-fashion. If the master is left with fewer nodes than the `discovery.zen.minimum_master_nodes`
|
|
|
|
|
-settings, it will step down and a new master election will start.
|
|
|
|
|
|
|
+fashion. If the master is left with too few nodes, it will step down and a new master election will start.
|
|
|
|
|
|
|
|
When a network partition causes a master node to lose many followers, there is a short window
|
|
When a network partition causes a master node to lose many followers, there is a short window
|
|
|
in time until the node loss is detected and the master steps down. During that window, the
|
|
in time until the node loss is detected and the master steps down. During that window, the
|
|
|
master may erroneously accept and acknowledge cluster state changes. To avoid this, we introduce
|
|
master may erroneously accept and acknowledge cluster state changes. To avoid this, we introduce
|
|
|
a new phase to cluster state publishing where the proposed cluster state is sent to all nodes
|
|
a new phase to cluster state publishing where the proposed cluster state is sent to all nodes
|
|
|
-but is not yet committed. Only once enough nodes (`discovery.zen.minimum_master_nodes`) actively acknowledge
|
|
|
|
|
|
|
+but is not yet committed. Only once enough nodes actively acknowledge
|
|
|
the change, it is committed and commit messages are sent to the nodes. See {GIT}13062[#13062].
|
|
the change, it is committed and commit messages are sent to the nodes. See {GIT}13062[#13062].
|
|
|
|
|
|
|
|
[float]
|
|
[float]
|
|
|
=== Wait on incoming joins before electing local node as master (STATUS: DONE, v2.0.0)
|
|
=== Wait on incoming joins before electing local node as master (STATUS: DONE, v2.0.0)
|
|
|
|
|
|
|
|
During master election each node pings in order to discover other nodes and validate the liveness of existing
|
|
During master election each node pings in order to discover other nodes and validate the liveness of existing
|
|
|
-nodes. Based on this information the node either discovers an existing master or, if enough nodes are found
|
|
|
|
|
-(see https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery-zen.html#master-election[`discovery.zen.minimum_master_nodes`]) a new master will be elected. Currently, the node that is
|
|
|
|
|
|
|
+nodes. Based on this information the node either discovers an existing master or, if enough nodes are found a new master will be elected. Currently, the node that is
|
|
|
elected as master will update the cluster state to indicate the result of the election. Other nodes will submit
|
|
elected as master will update the cluster state to indicate the result of the election. Other nodes will submit
|
|
|
a join request to the newly elected master node. Instead of immediately processing the election result, the elected master
|
|
a join request to the newly elected master node. Instead of immediately processing the election result, the elected master
|
|
|
node should wait for the incoming joins from other nodes, thus validating that the result of the election is properly applied. As soon as enough
|
|
node should wait for the incoming joins from other nodes, thus validating that the result of the election is properly applied. As soon as enough
|
James Rodewig