[kudu] 01/02: [docs] update the upgrade documentation

[aw...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

awong pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/kudu.git

commit 899f7a101d5713e8e010377d81c06a28e5095973
Author: helifu <hz...@corp.netease.com>
AuthorDate: Tue Jul 9 14:40:57 2019 +0800

    [docs] update the upgrade documentation
    
    The process of upgrading the cluster has been added to
    the installation.adoc.
    
    Change-Id: I6b3e5c549dc05c3388c0b0dd628d205a356da344
    Reviewed-on: http://gerrit.cloudera.org:8080/13820
    Tested-by: Kudu Jenkins
    Reviewed-by: Andrew Wong <aw...@cloudera.com>
---
 docs/installation.adoc | 54 ++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 52 insertions(+), 2 deletions(-)

diff --git a/docs/installation.adoc b/docs/installation.adoc
index a65792b..13e8672 100644
--- a/docs/installation.adoc
+++ b/docs/installation.adoc
@@ -632,8 +632,58 @@ Before upgrading, you should read the link:release_notes.html[Release Notes] for
 the version of Kudu that you are about to install. Pay close attention to the
 incompatibilities, upgrade, and downgrade notes that are documented there.
 
-NOTE: Currently rolling upgrades are not supported. Please shut down all Kudu services before
-  upgrading the software.
+WARNING: The following upgrade process is only relevant when you have binaries available.
+
+. Prepare the software.
+  - Place the new `kudu-tserver`, `kudu-master`, and `kudu` binaries into the appropriate
+    Kudu binary directory.
+. Upgrade the tablet servers.
+  - Set the `follower_unavailable_considered_failed_sec` configuration to a high value
+    (conservatively, twice the expected restart time) to prevent tablet replicas hosted
+    on restarting tablet servers from being evicted and re-replicated.
++
+[source,bash]
+----
+$ ./kudu tserver set_flag <tserver> follower_unavailable_considered_failed_sec 7200
+----
+  - Restart one tablet server.
+  - Wait for all tablet replicas on the tablet server to finish bootstrapping by viewing
+    `/tablets` page in the tablet server web UI.
+  - Restarting the tablet server will have reset the `follower_unavailable_considered_failed_sec`
+    configuration. Raise it again as needed.
+  - Repeat the previous 3 steps for the remaining tablet servers.
+  - Restore the original gflag value of every tablet server (the default is 5 minutes)
++
+[source,bash]
+----
+$ ./kudu tserver set_flag <tserver> follower_unavailable_considered_failed_sec 300
+----
++
+An example for a cluster with three tablet servers A, B, C:
++
+[source,bash]
+----
+# Step 1: Set the unavailable time for every tablet server to a large value
+$ ./kudu tserver set_flag A follower_unavailable_considered_failed_sec 7200
+$ ./kudu tserver set_flag B follower_unavailable_considered_failed_sec 7200
+$ ./kudu tserver set_flag C follower_unavailable_considered_failed_sec 7200
+
+# Step 2: Restart the tablet server and reset the gflag one by one
+<restart A and wait until A is online>
+$ ./kudu tserver set_flag A follower_unavailable_considered_failed_sec 7200
+<restart B and wait until B is online>
+$ ./kudu tserver set_flag B follower_unavailable_considered_failed_sec 7200
+<restart C and wait until C is online>
+$ ./kudu tserver set_flag C follower_unavailable_considered_failed_sec 7200
+
+# Step 3: Restore the default gflag value (5 minutes) for every tablet server
+$ ./kudu tserver set_flag A follower_unavailable_considered_failed_sec 300
+$ ./kudu tserver set_flag B follower_unavailable_considered_failed_sec 300
+$ ./kudu tserver set_flag C follower_unavailable_considered_failed_sec 300
+----
++
+. Upgrade the master servers.
+  - Restart the master server one by one.
 
 [[next_steps]]
 == Next Steps