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Posted to commits@samza.apache.org by "Jagadish (JIRA)" <ji...@apache.org> on 2016/03/17 08:50:33 UTC
[jira] [Updated] (SAMZA-899) Re-design the JobModel class
[ https://issues.apache.org/jira/browse/SAMZA-899?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jagadish updated SAMZA-899:
---------------------------
Description:
The current design of the JobModel class takes in a LocalityManager instance. The JobModel class also populates and mutates the container host mappings by reading from the LocalityManager. This state in the class is also mutated by the methods that make a call to populateContainerToHost mappings.
The JobModel class should *not* know who its LocalityManager is. The JobModel class must merely take in a *final* container-host mapping as a part of its constructor. (as opposed to taking in a LocalityManager and mutating state)
The JobModel class is currently shared from multiple threads, hence it's dangerous to expose public methods that mutate state without proper synchronization.
This re-design will ensure that the JobModel will be immutable and merely expose getters. This is important as the JobModel evolves into a standard interface that all systems that integrate with Samza will have to provide.
was:
The current design of the JobModel class takes in a LocalityManager instance. The JobModel class also populates and mutates the container host mappings by reading from the LocalityManager. This state in the class is also mutated by the methods that make a call to populateContainerToHost mappings.
Mutation of this state must be done external to the JobModel class. The JobModel class should *not* know who its LocalityManager is. The JobModel class must merely take in a *final* container-host mapping as a part of its constructor.
This re-design will ensure that the JobModel will be immutable and merely expose getters.
The JobModel class is shared from multiple threads, hence it's dangerous to expose methods that mutate state without proper synchronization.
> Re-design the JobModel class
> ----------------------------
>
> Key: SAMZA-899
> URL: https://issues.apache.org/jira/browse/SAMZA-899
> Project: Samza
> Issue Type: Bug
> Reporter: Jagadish
>
> The current design of the JobModel class takes in a LocalityManager instance. The JobModel class also populates and mutates the container host mappings by reading from the LocalityManager. This state in the class is also mutated by the methods that make a call to populateContainerToHost mappings.
> The JobModel class should *not* know who its LocalityManager is. The JobModel class must merely take in a *final* container-host mapping as a part of its constructor. (as opposed to taking in a LocalityManager and mutating state)
> The JobModel class is currently shared from multiple threads, hence it's dangerous to expose public methods that mutate state without proper synchronization.
> This re-design will ensure that the JobModel will be immutable and merely expose getters. This is important as the JobModel evolves into a standard interface that all systems that integrate with Samza will have to provide.
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