IMO, support for Kubernetes, Docker images, Mesos and anything outside
of Yarn deployments is a topic by itself and design for such support
needs to be discussed. I do not want to propose any specific design, but
assume that logic to create proper execution environment would be coded
into Apex client. Whether it (hardcoded logic to create an execution
environment) can be expressed simply as a list of dependent classes or
jars is at minimum questionable. Until design is proposed and agreed
upon, I'd prefer to use plugins for the subject.
On 2/2/18 13:17, Sanjay Pujare wrote:
In cases where we have an "über" docker image containing support for
multiple execution environments it might be useful for the Apex core to
infer what kind of execution environment to use for a particular
invocation (say based on configuration values/environment variables) and
in that case the core will load the corresponding libraries. And I think
this kind of flexibility or support would be difficult through the plugins
hence I think Sergey's proposal will be useful.
On Fri, Feb 2, 2018 at 11:18 AM, Sergey Golovko <ser...@datatorrent.com>
Unfortunately the moving of .apa file to a docker image cannot resolve all
problems with the dependencies. If we assume an Apex application should be
run in different execution environments, the application docker image must
contain all possible execution environment dependencies.
I think the better way is to assume that the original application docker
image like the current .apa file should contain the application specific
dependencies only. And some smart client tool should create the executable
application docker image form the original one and include the execution
specific environment dependencies into the target application docker image.
It means anyway an smart client Apex tool should have an interface to
define different environment dependencies or combination of different
dimensions of the environment dependencies.
On Fri, Feb 2, 2018 at 10:23 AM, Thomas Weise <t...@apache.org> wrote:
The current dependencies are based on how Apex YARN client works. YARN
depends on a DFS implementation for deployment (not necessarily HDFS).
I think a better way to look at this is to consider that instead of an
file the application is a docker image, which would contain Apex and all
dependencies that the "StramClient" today adds for YARN.
In that world there would be no Apex CLI or Apex specific client.
On Thu, Feb 1, 2018 at 5:57 PM, Sergey Golovko <ser...@datatorrent.com>
I agree. It can be implemented with usage of plugins. But if I need to
enable and configurate the plugin I need to put this information into
dt-site.xml. It means The plugin and its parameter must be documented
the list of the added specific jars will be visible and available for
updates to the end-user. The implementation via plugins is more dynamic
solution that is more convenient for the application developers. But
talking about the static configuration of the Apex build or
that relates more to the platform development.
The current Apex core implementation uses the static unchanged list of
for long time, because the Apex implementation still contains several
static assumptions (for instance, the usage of YARN, HDSF, etc.). And
current Apex assumptions are hardcoded in the implementation. But if we
going to improve Apex and use Java interfaces in generic Apex
implementation, the current static approach in Apex code to hardcode a
of dependent jars will not work anymore. It will require to include a
solution to add/change jars in specific Apex builds/configurations.
don't think the usage of the plugins will be good for that.
On Thu, Feb 1, 2018 at 1:47 PM, Vlad Rozov <vro...@apache.org> wrote:
There is a way to get the same end result by using plugins. It will
good to understand why plugin can't be used and can they be extended
provide the required functionality.
On 1/29/18 15:14, Sergey Golovko wrote:
In Apex there are two ways to deploy non-Hadoop jars to the deployed
The first approach is static (hardcoded) and it is used by Apex
developers only. There are several final static arrays of Java
that define which of the available jars should be included into
for every Apex application.
The second approach is to add paths of all dependent jar-files to
of the attribute LIB_JARS. The end-user can set/update the value of
attribute LIB_JARS via dt-site.xml files, command line parameters,
application properties and plugins. The usage of the
attribute LIB_JARS is the official documented way for all Apex users
manage by the deployment jars.
But some of the dependent jars (not from the Apex core) can be
all customer's applications for a specific installation and/or
environment. Unfortunately the Apex implementation does not contain
middle solution that would allow the Apex developers and customer
define and add new dependent jar-files (jars that should not be
configurable/managed by the end-user) without the
the Apex Java code during the Apex building process and/or
Also the having of such kind of flexibility would allow the Apex
developers to use Java interfaces during the development to define
abstraction layer in Apex implementation and configurate Apex core
some specific jars to all Apex applications without recompilation of
Apex source code.
For instance, now the usage of HDFS is hardcoded in Apex platform
it can be replaced with any other distributed or cloud base file
The Apex core code can use an interface for all I/O operations but
supporting of a real specific file system implementation can be
independent jar-file. Or if the implementation of some of Apex
depend on a specific service, and it is necessary to add some of the
service jars to every Apex application implicitly.
- add a predefined configuration text file (we can make any choice
file syntax: XML, JSON or Properties) to Apex engine resources with
predefined values of some of the Apex attributes (now we can include
- allow to have a configuration text file with the same
the Apex installation folder "conf";
- read the content of the predefined configuration text files by the
client in runtime and add the jars to the list of the dependent
- allow to use paths to jars and Java classes to refer to the
jars (the references can have the extensions: .class and .jar).