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https://issues.apache.org/jira/browse/HBASE-15071?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15085087#comment-15085087
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Heng Chen edited comment on HBASE-15071 at 1/6/16 9:27 AM:
-----------------------------------------------------------
{quote}
The point of bypass is to skip further core code processing. The coprocessor
says it has taken care of everything, time to return back to the client taking
no further action. What you propose directly contravenes this semantic in place
everywhere a coprocessor can call bypass()
{quote}
Hmm... Sounds reasonable...
So we should make all "pre" actions respect bypass returned (e.g.
preDeleteTable did not return bypass, we should return it and respect it ),
right?
There are some special case, e.g. preGetNamespaceDescriptor, currently it
return nothing, but as bypass logic, it should return one
{{NamespaceDescriptor}} instance and the caller will use bypass to decide
whether we should return it to client or not, but if so, it will be
incompatible with old observer.
Or we can just comment the interface "it can't bypass the default action" just
like preListSnapshot did now. And i notice except {{preBalanceSwitch}}, all
interfaces in MasterObserver return nothing, is it means we just bypass the
default action and return something arbitrary is fine? If so, maybe we should
modify the semantic of bypass.....
Thanks [~apurtell] for your reply.
was (Author: chenheng):
{quote}
The point of bypass is to skip further core code processing. The coprocessor
says it has taken care of everything, time to return back to the client taking
no further action. What you propose directly contravenes this semantic in place
everywhere a coprocessor can call bypass()
{quote}
Hmm... Sounds reasonable...
So we should make all "pre" actions respect bypass returned (e.g.
preDeleteTable did not return bypass, we should return it and respect it ),
right?
There are some special case, e.g. preGetNamespaceDescriptor, currently it
return nothing, but as bypass logic, it should return one
{{NamespaceDescriptor}} instance and the caller will use bypass to decide
whether we should return it to client. Or we can comment the interface it
can't bypass the default action just like preListSnapshot did now.
Thanks [~apurtell] for your reply.
> Cleanup bypass semantic in MasterCoprocessorHost
> ------------------------------------------------
>
> Key: HBASE-15071
> URL: https://issues.apache.org/jira/browse/HBASE-15071
> Project: HBase
> Issue Type: Task
> Components: Coprocessors
> Affects Versions: 2.0.0
> Reporter: stack
> Priority: Blocker
>
> Lets decide on this one before we release 2.0.0.
> A bunch of methods in MasterCoprocessorHost on the 'pre' step allow returning
> true which indicates the method invocation is not to proceed.
> Not all 'pre' steps do this. Just some.
> Seems a little arbitrary.
> How we skip out if we are not proceed with the invocation is also a little
> arbitrary.
> When a deleteColumn call is supposed to skip out, it returns a -1, a
> non-procId. If we are to skip a balance call, we log that CP said skip and
> then return false to indicate the balancer did not run (why?). Elsewhere we
> just exit silently. In createNamespace we used to exit silently but
> HBASE-14888 just changed it so we throw a BypassCoprocessorException
> instead...
> Lets make them all work the same way.
> (This issue comes of chat w/ Matteo)
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