This is an automated email from the ASF dual-hosted git repository.
alexey pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/kudu.git
commit d411dd1b41a47a5d9f1ee9b68911aa5952475896
Author: Alexey Serbin <ale...@apache.org>
AuthorDate: Tue May 3 14:41:57 2022 -0700
[docs] update a few notes on multi-master migration
This patch updates the warning note for the multi-master migration
section (of course, that's for 1.15 and newer versions) to bring more
clarity on what components to be restarted if not using DNS aliases.
The prior '... bringing the cluster down for maintenance ...' was not
technically correct since it's possible to perform rolling restart of
tablet servers in the cluster.
In addition, the obsolete warning note about the multi-master
migration procedure being unsafe is removed. The new multi-master
migration procedure (for 1.15 and newer versions) is universal and
safe when migrating from N to N+1 masters.
Change-Id: Ie707e8342adf7a5e557079a4121a50d009f7602f
Reviewed-on: http://gerrit.cloudera.org:8080/18487
Tested-by: Kudu Jenkins
Reviewed-by: Attila Bukor <abu...@apache.org>
---
docs/administration.adoc | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/docs/administration.adoc b/docs/administration.adoc
index 2ba1525ca..b7c0c0306 100644
--- a/docs/administration.adoc
+++ b/docs/administration.adoc
@@ -528,9 +528,6 @@ quorum. The below steps do not need to be performed in
these versions.
NOTE: From Kudu version 1.15.0 onwards, the `kudu master add` command has been
added that simplifies
the orchestration to migrate an existing Kudu cluster to multiple masters.
-WARNING: The workflow is unsafe for adding new masters to an existing
configuration that already has
-three or more masters. Do not use it for that purpose.
-
WARNING: An even number of masters doesn't provide any benefit over having one
fewer masters. This
guide should always be used for migrating to three masters.
@@ -561,8 +558,10 @@ and restart the single master.
or an alias in /etc/hosts. The alias should be an abstract representation of
the master (e.g.
`master-1`).
+
-WARNING: Without DNS aliases it is not possible to recover from permanent
master failures without
-bringing the cluster down for maintenance, and as such, it is highly
recommended.
+WARNING: Without DNS aliases it is not possible to recover from permanent
+master failures without restarting the tablet servers in the cluster
+to pick up the replacement master node at different hostname. It is highly
+recommended to use DNS aliases for Kudu master nodes to avoid that.
+
. If you have Kudu tables that are accessed from Impala, you must update
the master addresses in the Apache Hive Metastore (HMS) database.
