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https://issues.apache.org/jira/browse/HBASE-18359?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16254736#comment-16254736
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Anoop Sam John commented on HBASE-18359:
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[~samarth.j...@gmail.com], [~sergey.soldatov]. Coming to this jira again.
In trunk, things are changed a lot and there is no CoprocessorHConnection any
more. We have CoprocessorEnvironment#getConnection(). This will give short
circuited connection. Means any calls, via this connection , on regions in same
RS will go a short circuited path.
On the old code u mentioned, we were passing CoprocessorEnvironment. This is
the object u r getting from HBase core and you can just GET config from that.
This is the same config that Region uses. So am not sure how u can create
custom conf. You can not really set any config in CoprocessorEnvironment
object. I guess what u were doing is just changing /setting some config
attributes on the config getting from CoprocessorEnvironment. That will be
wrong. Because the conf object is a shared one for every thing in this Region.
All CPs over this Region and Region, Store and level down will use this changed
config. What ideally should be done is clone the config and set the new
attributes. If we were having an API which takes Config, it would have been
possible. Also CoprocessorHConnection was a Private class.
So this is not the ideal path for what you want to do.
Checking the new trunk code also, seems you can not do what u really want.
Because all calls CoprocessorEnvironment#getConnection() will return a same
Cluster connection object which is created in HRS. So if u need to have
custom configs to be used for these connection, only way would be to have a
CoprocessorEnvironment#getConnection(Config) API and create new connection
(Short circuited) in the impl. Not good to create the connection on every
call. We have to decide who will do the caching of the connection and reuse.
cc [~Stack]
> CoprocessorHConnection#getConnectionForEnvironment should read config from
> CoprocessorEnvironment
> -------------------------------------------------------------------------------------------------
>
> Key: HBASE-18359
> URL: https://issues.apache.org/jira/browse/HBASE-18359
> Project: HBase
> Issue Type: Bug
> Reporter: Samarth Jain
>
> It seems like the method getConnectionForEnvironment isn't doing the right
> thing when it is creating a CoprocessorHConnection by reading the config from
> HRegionServer and not from the env passed in.
> If coprocessors want to use a CoprocessorHConnection with some custom config
> settings, then they have no option but to configure it in the hbase-site.xml
> of the region servers. This isn't ideal as a lot of times these "global"
> level configs can have side effects. See PHOENIX-3974 as an example where
> configuring ServerRpcControllerFactory (a Phoenix implementation of
> RpcControllerFactory) could result in deadlocks. Or PHOENIX-3983 where
> presence of this global config causes our index rebuild code to incorrectly
> use handlers it shouldn't.
> If the CoprocessorHConnection created through getConnectionForEnvironment API
> used the CoprocessorEnvironment config, then it would allow co-processors to
> pass in their own config without needing to configure them in hbase-site.xml.
> The change would be simple. Basically change the below
> {code}
> if (services instanceof HRegionServer) {
> return new CoprocessorHConnection((HRegionServer) services);
> }
> {code}
> to
> {code}
> if (services instanceof HRegionServer) {
> return new CoprocessorHConnection(env.getConfiguration(),
> (HRegionServer) services);
> }
> {code}
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