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https://issues.apache.org/jira/browse/HBASE-3260?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Andrew Purtell updated HBASE-3260:
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Description:
Considering extending CPs to the master, we have no equivalent to pre/postOpen
and pre/postClose as on the regionserver. We also should consider how to
resolve dependencies and initialization ordering if loading coprocessors that
depend on others.
OSGi (http://en.wikipedia.org/wiki/OSGi) has a lifecycle API and is familiar to
many Java programmers, so we propose to borrow its terminology and state
machine.
A lifecycle layer manages coprocessors as they are dynamically installed,
started, stopped, updated and uninstalled. Coprocessors rely on the framework
for dependency resolution and class loading. In turn, the framework calls up to
lifecycle management methods in the coprocessor as needed.
A coprocessor transitions between the below states over its lifetime:
||State||Description||
|UNINSTALLED|The coprocessor implementation is not installed. This is the
default implicit state.|
|INSTALLED|The coprocessor implementation has been successfully installed|
|STARTING|A coprocessor instance is being started.|
|ACTIVE|The coprocessor instance has been successfully activated and is
running.|
|STOPPING|A coprocessor instance is being stopped.|
See attached state diagram. Transitions to STOPPING will only happen as the
region is being closed. If a coprocessor throws an unhandled exception, this
will cause the RegionServer to close the region, stopping all coprocessor
instances on it.
Transitions from INSTALLED->STARTING and ACTIVE->STOPPING would go through
upcall methods into the coprocessor via the CoprocessorLifecycle interface:
{code:java}
public interface CoprocessorLifecycle {
void start(CoprocessorEnvironment env) throws IOException;
void stop(CoprocessorEnvironment env) throws IOException;
}
{code}
Fix Version/s: 0.92.0
> Coprocessors: Lifecycle management
> ----------------------------------
>
> Key: HBASE-3260
> URL: https://issues.apache.org/jira/browse/HBASE-3260
> Project: HBase
> Issue Type: Sub-task
> Reporter: Andrew Purtell
> Fix For: 0.92.0
>
>
> Considering extending CPs to the master, we have no equivalent to
> pre/postOpen and pre/postClose as on the regionserver. We also should
> consider how to resolve dependencies and initialization ordering if loading
> coprocessors that depend on others.
> OSGi (http://en.wikipedia.org/wiki/OSGi) has a lifecycle API and is familiar
> to many Java programmers, so we propose to borrow its terminology and state
> machine.
> A lifecycle layer manages coprocessors as they are dynamically installed,
> started, stopped, updated and uninstalled. Coprocessors rely on the framework
> for dependency resolution and class loading. In turn, the framework calls up
> to lifecycle management methods in the coprocessor as needed.
> A coprocessor transitions between the below states over its lifetime:
> ||State||Description||
> |UNINSTALLED|The coprocessor implementation is not installed. This is the
> default implicit state.|
> |INSTALLED|The coprocessor implementation has been successfully installed|
> |STARTING|A coprocessor instance is being started.|
> |ACTIVE|The coprocessor instance has been successfully activated and is
> running.|
> |STOPPING|A coprocessor instance is being stopped.|
> See attached state diagram. Transitions to STOPPING will only happen as the
> region is being closed. If a coprocessor throws an unhandled exception, this
> will cause the RegionServer to close the region, stopping all coprocessor
> instances on it.
> Transitions from INSTALLED->STARTING and ACTIVE->STOPPING would go through
> upcall methods into the coprocessor via the CoprocessorLifecycle interface:
> {code:java}
> public interface CoprocessorLifecycle {
> void start(CoprocessorEnvironment env) throws IOException;
> void stop(CoprocessorEnvironment env) throws IOException;
> }
> {code}
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