Author: gourksaha
Date: Tue May 19 15:33:12 2015
New Revision: 1680318
URL: http://svn.apache.org/r1680318
Log:
few modifications of upgrade verbiage
Modified:
incubator/slider/site/trunk/content/docs/slider_specs/application_pkg_upgrade.md
Modified:
incubator/slider/site/trunk/content/docs/slider_specs/application_pkg_upgrade.md
URL:
http://svn.apache.org/viewvc/incubator/slider/site/trunk/content/docs/slider_specs/application_pkg_upgrade.md?rev=1680318&r1=1680317&r2=1680318&view=diff
==============================================================================
---
incubator/slider/site/trunk/content/docs/slider_specs/application_pkg_upgrade.md
(original)
+++
incubator/slider/site/trunk/content/docs/slider_specs/application_pkg_upgrade.md
Tue May 19 15:33:12 2015
@@ -30,7 +30,7 @@ to `1.1.0`, then sufficient **_regionser
at the time of the upgrade. Application owners also need to ensure that their
application is compatible
in a mixed version mode. So, while the **_regionservers_** are getting
upgraded, the **_master_** will
still be the older version. Hence `1.1.0` **_regionserver_** should be
backward compatible with `0.98.4`
-**_masters_**.
+**_master_**.
Currently, _Ambari Slider View_ supports automated deployment and management
of application packages.
Automated application package upgrade will be supported soon.
@@ -38,19 +38,19 @@ Automated application package upgrade wi
## Phases of Upgrade/Downgrade
#### YARN core (libraries and configurations) upgrade/downgrade
-Running Slider apps will continue to run, with no downtime
+> Running Slider apps will continue to run, with no downtime
#### Slider client upgrade/downgrade
-Does not affect running Slider apps at all. New version of client can co-exist
with older versions.
+> Does not affect running Slider apps at all. New version of client can
co-exist with older versions of client.
#### Slider Application Master upgrade/downgrade of running applications
-Applications started prior to the start of YARN core upgrade/downgrade, will
continue to run with the
-older versions of Slider and Hadoop core libraries. To upgrade running Slider
AMs the application needs
-to be stopped and restarted with the new version of the client. There is no
support for rolling upgrade
-of Slider AM.
+> Applications started prior to the start of YARN core upgrade/downgrade, will
continue to run with the
+older versions of Slider core and Hadoop libraries. There is no support for
rolling upgrade of Slider AM.
+To upgrade running Slider AMs, the application needs to be stopped and
restarted with the new version
+of the client.
#### Applications deployed by Slider (binaries and configurations)
upgrade/downgrade
-This is the what this document is primarily about.
+> This is the what this document is primarily about.
## Upgrade Slider Application Packages
@@ -58,6 +58,15 @@ A run-book style list of atomic steps ex
by Apache Ambari in a future release. It can be easily orchestrated by a shell
script
or executed manually in the correct order.
+Note, the following YARN property should be specified to a reasonably high
value (say 5 or 10) before performing
+application upgrade. The default value of this property in a YARN cluster is
set to 2, which is not recommended
+for long running applications (specifically when performing upgrade).
+
+ <property>
+ <name>yarn.resourcemanager.am.max-attempts</name>
+ <value>10</value>
+ </property>
+
### An application owner brings a new package and creates a new instance
Upload a new application package *slider-hbase-app-package_v1.0.zip*
@@ -66,11 +75,11 @@ Upload a new application package *slider
Create an application *MyHBase_Facebook_Finance*
- slider create MyHBase_Facebook_Finance --template
~/myHBase_template_v1.0.json --resources ~/myHBase_resources_v1.0.json
+ slider create MyHBase_Facebook_Finance --template
~/myHBase_appConfig_v1.0.json --resources ~/myHBase_resources_v1.0.json
-Application *MyHBase_Facebook_Finance* goes through its usual lifecycle
+Application *MyHBase_Facebook_Finance* goes through its usual lifecycle, say
flex *regionservers* up
- slider flex MyHBase_Facebook_Finance --component HBASE_MASTER 5
+ slider flex MyHBase_Facebook_Finance --component HBASE_REGIONSERVER 5
### The app owner can list all containers of an app instance with filtering
options
@@ -84,27 +93,27 @@ Application *MyHBase_Facebook_Finance* g
### At some point, the app owner has a newer version of the package and needs
to upgrade
-Uploads the newer version 2.0 of the app package
+Upload the newer version 2.0 of the app package
slider package --install --name MyHBase_Facebook --version 2.0 --package
~/slider-hbase-app-package_v2.0.zip
-This command upgrades the internal state of Slider App Master with the new
config and resource
-specifications. After this, upgrade command needs to be issued against all
containers to upgrade
+The following command upgrades the internal state of Slider App Master with
the new config and resource
+specifications. After this, upgrade command needs to be issued against all
containers, to upgrade
them to the new app version e.g. v2.0 in this case. Note, it is recommended to
not issue the
-flex command, although Slider does not explicitly block it.
+flex command until all containers are upgraded, although Slider does not
explicitly block it.
- slider upgrade MyHBase_Facebook_Finance --template
~/myHBase_template_v2.0.json --resources ~/myHBase_resources_v2.0.json
+ slider upgrade MyHBase_Facebook_Finance --template
~/myHBase_appConfig_v2.0.json --resources ~/myHBase_resources_v2.0.json
At this point the upgrade orchestrator (Ambari or a script) will rely on the
slider `list` command with
`--containers` option (with additional filter options `--components` and/or
`--version`) to find all
the containers that are running for the application. The orchestrator needs to
decide how it wants to
span/schedule the upgrade commands of every single container. This will
primarily depend on the
-type of the application. For e.g. say *HBase* might want to call upgrade on
all *Master* containers
+type of the application. For e.g. say, *HBase* might want to call upgrade on
the *Master* container(s)
first before calling upgrade on any of the *RegionServer* containers. *Storm*
might want to provide
a 5 min delay between the upgrade of the *Nimbus* and *Supervisor*
container(s).
Upgrade all containers with ids `id1, id2, .. idn`. It is possible that all
these n containers can
-actually be down at the same time. If this is not desired, then issue n
upgrade command with a
+actually be down at the same time. If this is not desired, then issue n
upgrade commands with a
single container id at a time.
slider upgrade MyHBase_Facebook_Finance --containers id1 id2 .. idn
@@ -121,9 +130,10 @@ one container at a time.
### When do we know that upgrade is complete?
-The upgrade command need to be executed against all containers and upgrade can
be considered
-complete only if the command `slider list MyHBase_Facebook_Finance
--containers --version 1.0`
-returns no containers.
+The upgrade command needs to be executed against all containers. Upgrade can
be considered
+complete only if the following command returns no containers.
+
+ slider list MyHBase_Facebook_Finance --containers --version 1.0
The app owner can also call `slider list MyHBase_Facebook_Finance
--containers` to explicitly
check that all expected containers are running and with the desired new
version (e.g. 2.0 in
@@ -144,9 +154,9 @@ were upgraded to the newer version.
This command although called upgrade, actually downgrades the internal state
of Slider App
Master with the old v1.0 config and resource specifications
- slider upgrade MyHBase_Facebook_Finance --template
~/myHBase_template_v1.0.json --resources ~/myHBase_resources_v1.0.json
+ slider upgrade MyHBase_Facebook_Finance --template
~/myHBase_appConfig_v1.0.json --resources ~/myHBase_resources_v1.0.json
-Take the list of all containers returned by the list command -
+Gather the list of all containers returned by the *list* command -
slider list MyHBase_Facebook_Finance --containers --version 2.0
@@ -154,38 +164,50 @@ And issue upgrade command on all of them
slider upgrade MyHBase_Facebook_Finance --containers id1 id2 .. idn
+Downgrade is done when the following command returns no containers.
+
+ slider list MyHBase_Facebook_Finance --containers --version 2.0
+
## Pre and post upgrade hooks
### Pre-upgrade hook (optional)
-The pre-upgrade steps, if provided, will allow applications to execute simple
housekeeping tasks
+> The pre-upgrade steps, if provided, will allow applications to execute
simple housekeeping tasks
before Slider actually calls stop operation in an upgrade scenario
(specifically if they need to
be performed in every single container and 1000s of them are running). An
example could be to
send a message to a queue that the current instance of memcached is going down
so that the load
balancer rules can be dynamically updated. Performing long-running tasks or
tasks that needs to
be executed by only 1 instance of a component (n instances of which are
running) should be
-performed manually before calling upgrade (or maybe before calling the upgrade
command). The
+performed manually before starting the upgrade process. The
pre-upgrade hook is not a good candidate for such operations. Additional
parameters might have
to be exposed, like timeout, which can be used to wait at most n seconds (say)
after which Slider
will call the application stop hook even if the pre-upgrade operation is not
completed.
-### Post-upgrade hook (optional) - not yet supported
-This allows applications to perform simple housekeeping tasks prior to calling
start on the new
+> Use `app-packages/hbase/package/scripts/hbase_master.py` as a sample for
defining the
+pre-upgrade hook. Note, the pre-upgrade hook will be triggered only if the
currently running
+application has been created using Slider verion `0.80.0-incubating` or later
and the scripts
+in the package has the pre-upgrade hook defined.
+
+### Post-upgrade hook (optional) - `not yet supported`
+> This allows applications to perform simple housekeeping tasks prior to
calling start on the new
version of the application component. This is helpful only if such tasks are
required to be
-performed in every single container and 1000s of them are running. This is
required only in the
-upgrade scenario and should not be called on new containers created using flex
up in non-upgrade
-scenarios. This is tricky, how will Slider determine this? I donât think we
need a post-upgrade
-hook? Clarify with Rakesh and remove?
+performed in every single container and 1000s of them are running. This hook
will be triggered only in the
+upgrade scenario. It will not be called on new containers created using flex
up, in non-upgrade
+scenarios. This makes triggering of post-upgrade hook a little tricky and
hence is not supported
+today. This will be looked into, in future releases.
## Upgrade support of simple apps with no packages
- Upgrade of such simple apps does not involve binaries
- Upgrade of such simple apps basically means re-configuration only
- The following can be done to perform the reconfiguration (or upgrade if you
prefer to call so)
- - Download the app package that was internally created by Slider from HDFS
(First class Slider
- command-line support will not be provided for download. So refer to
documentation or get
- Slider/Yarn admin support to find the app package location in HDFS.)
+ - Download the app package that was internally created by Slider from
HDFS. This is the path
+ defined in `application.def` property in the *appConfig.json* file.
Slider client command-line
+ support is not available to perform this download (yet). So, refer to
documentation or get
+ Slider/Yarn admin support if required.
+ - Unzip the application package
- Make necessary changes to metainfo.json and repackage the app
- Make necessary updates to appConfig.json and resources.json
- - Follow the upgrade steps provided in this document to upgrade the simple
app
+ - Re-package the application package (this is the newer version of your
package, say v2.0)
+ - Follow the upgrade steps provided in this document to upgrade the simple
app to v2.0
## Assumptions/Recommendations
@@ -195,10 +217,9 @@ hook? Clarify with Rakesh and remove?
(on which the upgrade command was not called yet) fails, then its
replacement container will
come up with the newer version of the application.
- It is recommended to not call `flex` (to increase or decrease the no of
containers assigned
- to a specific role) after the upgrade command has been issued and until
upgrade command is
+ to a specific role) after the upgrade spec command has been issued and until
upgrade command is
issued on all currently running containers (as per current resource
specification). Basically
avoid calling flex until `slider list --containers --version <old_ver>`
returns no more
containers. Note, flex command is not explicitly blocked by Slider, hence
unexpected
- behavior of the application might occur if called.
-
+ behavior of the application might occur, if called.
